Agricultural and Biological Sciences › Agronomy and Crop Science

Ruminant Nutrition and Digestive Physiology

Works Count: 102171

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Description

This cluster of papers explores various aspects of ruminant nutrition, with a focus on strategies to optimize health, production, and environmental impact. Topics include methane production, microbial communities in the rumen, effects of dietary tannins, rumen fermentation, milk composition, feed efficiency, subacute ruminal acidosis, and fatty acid composition. The research aims to improve the understanding and management of nutritional factors affecting ruminant health and productivity.

Keywords

Ruminant Nutrition; Methane Production; Microbial Community; Dietary Tannins; Rumen Fermentation; Milk Composition; Feed Efficiency; Subacute Ruminal Acidosis; Fatty Acid Composition; Forage Quality

Forage in Ruminant Nutrition

1990-01-01

Dennis J. Minson

A net carbohydrate and protein system for evaluating cattle diets: II. Carbohydrate and protein availability

1992-11-01

C.J. Sniffen , John D. O’Connor , P.J. Van Soest +2 more

The Cornell Net Carbohydrate and Protein System (CNCPS) has a submodel that predicts rates of feedstuff degradation in the rumen, the passage of undegraded feed to the lower gut, and … The Cornell Net Carbohydrate and Protein System (CNCPS) has a submodel that predicts rates of feedstuff degradation in the rumen, the passage of undegraded feed to the lower gut, and the amount of ME and protein that is available to the animal. In the CNCPS, structural carbohydrate (SO and nonstructural carbohydrate (NSC) are estimated from sequential NDF analyses of the feed. Data from the literature are used to predict fractional rates of SC and NSC degradation. Crude protein is partitioned into five fractions. Fraction A is NPN, which is trichloroacetic (TCA) acid-soluble N. Unavailable or protein bound to cell wall (Fraction C) is derived from acid detergent insoluble nitrogen (ADIP), and slowly degraded true protein (Fraction B3) is neutral detergent insoluble nitrogen (NDIP) minus Fraction C. Rapidly degraded true protein (Fraction B1) is TCA-precipitable protein from the buffer-soluble protein minus NPN. True protein with an intermediate degradation rate (Fraction B2) is the remaining N. Protein degradation rates are estimated by an in vitro procedure that uses Streptomyces griseus protease, and a curve-peeling technique is used to identify rates for each fraction. The amount of carbohydrate or N that is digested in the rumen is determined by the relative rates of degradation and passage. Ruminal passage rates are a function of DMI, particle size, bulk density, and the type of feed that is consumed (e.g., forage vs cereal grain).

Methane emissions from cattle

1995-08-01

Kristen Johnson , Donald E. Johnson

Increasing atmospheric concentrations of methane have led scientists to examine its sources of origin. Ruminant livestock can produce 250 to 500 L of methane per day. This level of production … Increasing atmospheric concentrations of methane have led scientists to examine its sources of origin. Ruminant livestock can produce 250 to 500 L of methane per day. This level of production results in estimates of the contribution by cattle to global warming that may occur in the next 50 to 100 yr to be a little less than 2%. Many factors influence methane emissions from cattle and include the following: level of feed intake, type of carbohydrate in the diet, feed processing, addition of lipids or ionophores to the diet, and alterations in the ruminal microflora. Manipulation of these factors can reduce methane emissions from cattle. Many techniques exist to quantify methane emissions from individual or groups of animals. Enclosure techniques are precise but require trained animals and may limit animal movement. Isotopic and nonisotopic tracer techniques may also be used effectively. Prediction equations based on fermentation balance or feed characteristics have been used to estimate methane production. These equations are useful, but the assumptions and conditions that must be met for each equation limit their ability to accurately predict methane production. Methane production from groups of animals can be measured by mass balance, micrometeorological, or tracer methods. These techniques can measure methane emissions from animals in either indoor or outdoor enclosures. Use of these techniques and knowledge of the factors that impact methane production can result in the development of mitigation strategies to reduce methane losses by cattle. Implementation of these strategies should result in enhanced animal productivity and decreased contributions by cattle to the atmospheric methane budget.

Rumen microbial community composition varies with diet and host, but a core microbiome is found across a wide geographical range

2015-10-09

Gemma Henderson , Faith Cox , Siva Ganesh +7 more

Abstract Ruminant livestock are important sources of human food and global greenhouse gas emissions. Feed degradation and methane formation by ruminants rely on metabolic interactions between rumen microbes and affect … Abstract Ruminant livestock are important sources of human food and global greenhouse gas emissions. Feed degradation and methane formation by ruminants rely on metabolic interactions between rumen microbes and affect ruminant productivity. Rumen and camelid foregut microbial community composition was determined in 742 samples from 32 animal species and 35 countries, to estimate if this was influenced by diet, host species, or geography. Similar bacteria and archaea dominated in nearly all samples, while protozoal communities were more variable. The dominant bacteria are poorly characterised, but the methanogenic archaea are better known and highly conserved across the world. This universality and limited diversity could make it possible to mitigate methane emissions by developing strategies that target the few dominant methanogens. Differences in microbial community compositions were predominantly attributable to diet, with the host being less influential. There were few strong co-occurrence patterns between microbes, suggesting that major metabolic interactions are non-selective rather than specific.

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Energy contributions of volatile fatty acids from the gastrointestinal tract in various species

1990-04-01

E. N. Bergman

The VFA, also known as short-chain fatty acids, are produced in the gastrointestinal tract by microbial fermentation of carbohydrates and endogenous substrates, such as mucus. This can be of great … The VFA, also known as short-chain fatty acids, are produced in the gastrointestinal tract by microbial fermentation of carbohydrates and endogenous substrates, such as mucus. This can be of great advantage to the animal, since no digestive enzymes exist for breaking down cellulose or other complex carbohydrates. The VFA are produced in the largest amounts in herbivorous animal species and especially in the forestomach of ruminants. The VFA, however, also are produced in the lower digestive tract of humans and all animal species, and intestinal fermentation resembles that occurring in the rumen. The principal VFA in either the rumen or large intestine are acetate, propionate, and butyrate and are produced in a ratio varying from approximately 75:15:10 to 40:40:20. Absorption of VFA at their site of production is rapid, and large quantities are metabolized by the ruminal or large intestinal epithelium before reaching the portal blood. Most of the butyrate is converted to ketone bodies or CO2 by the epithelial cells, and nearly all of the remainder is removed by the liver. Propionate is similarly removed by the liver but is largely converted to glucose. Although species differences exist, acetate is used principally by peripheral tissues, especially fat and muscle. Considerable energy is obtained from VFA in herbivorous species, and far more research has been conducted on ruminants than on other species. Significant VFA, however, are now known to be produced in omnivorous species, such as pigs and humans. Current estimates are that VFA contribute approximately 70% to the caloric requirements of ruminants, such as sheep and cattle, approximately 10% for humans, and approximately 20-30% for several other omnivorous or herbivorous animals. The amount of fiber in the diet undoubtedly affects the amount of VFA produced, and thus the contribution of VFA to the energy needs of the body could become considerably greater as the dietary fiber increases. Pigs and some species of monkey most closely resemble humans, and current research should be directed toward examining the fermentation processes and VFA metabolism in those species. In addition to the energetic or nutritional contributions of VFA to the body, the VFA may indirectly influence cholesterol synthesis and even help regulate insulin or glucagon secretion. In addition, VFA production and absorption have a very significant effect on epithelial cell growth, blood flow, and the normal secretory and absorptive functions of the large intestine, cecum, and rumen. The absorption of VFA and sodium, for example, seem to be interdependent, and release of bicarbonate usually occurs during VFA absorption.(ABSTRACT TRUNCATED AT 400 WORDS)

A theoretically-based model for predicting total digestible nutrient values of forages and concentrates

1992-11-01

W.P. Weiss , H.R. Conrad , N.R. St. Pierre

Gravimetric determination of tannins and their correlations with chemical and protein precipitation methods

1993-01-01

H.P.S. Makkar , Michael Blümmel , N.K. Borowy +1 more

Abstract Abstract. A method for gravimetric determination of tannins based on binding with insoluble polyvinylpyrrolidone (PVP) is presented. The gravimetric method gives the absolute amount of tannins and avoids problems … Abstract Abstract. A method for gravimetric determination of tannins based on binding with insoluble polyvinylpyrrolidone (PVP) is presented. The gravimetric method gives the absolute amount of tannins and avoids problems of standards associated with spectrophotometric methods. The method was applied to nine browse and tree leaves. The values obtained correlate significantly with tannins determined spectrophotometrically, protein precipitation capacities and protein precipitable phenotics. This method together with other tannin assays will be useful in nutritional studies. The present study also demonstrates the different behaviour of tannic acids from different commercial sources towards PVP suggesting the presence of different moieties in tannic acids from different commercial sources and even among batches from the same source thereby affecting the results obtained using the spectrophotometric methods. Use of well‐defined tannic acid as a standard in spectrophotometric methods is suggested which will allow meaningful comparison of values obtained from different laboratories.

The Rumen Microbial Ecosystem

1997-01-01

P. N. Hobson , C.S. Stewart

Fat in Lactation Rations : Review

1980-01-01

D.L. Palmquist , T.C. Jenkins

Evolutionary steps of ecophysiological adaptation and diversification of ruminants: a comparative view of their digestive system

1989-01-01

R. R. Hofmann

Standardization of procedures for nitrogen fractionation of ruminant feeds

1996-03-01

G. Licitra , Torres Hernández , P.J. Van Soest

The Cornell Net Carbohydrate Protein Model (Chalupa et al., 1991;Sniffen et al., 1992) has developed the need for uniform procedures to partition feed nitrogen into A, B, and C fractions … The Cornell Net Carbohydrate Protein Model (Chalupa et al., 1991;Sniffen et al., 1992) has developed the need for uniform procedures to partition feed nitrogen into A, B, and C fractions (Pichard and Van Soest, 1977).While carbohydrate fractions are relatively standardized (based on NDF, ADF with corrections for ash, protein, and lignin), the fractionation of plant nitrogen has been open to considerable variation in procedures.This has led to non-uniformity among reported values for nitrogen fractions.This paper recommends reliable procedures for nonprotein nitrogen (NPN) and buffer-soluble protein.These procedures have been examined for reproducibility and relevance to biological expectations.Procedures for acid-detergent insoluble nitrogen (ADIN), and neutral-detergent insoluble nitrogen (NDIN) am also included as they are required for the model.Some alternatives in certain procedures are offered.

Methods for Dietary Fiber, Neutral Detergent Fiber, and Nonstarch Polysaccharides in Relation to Animal Nutrition

1991-10-01

P.J. Van Soest , James B. Robertson , B.A. Lewis

There is a need to standardize the NDF procedure.Procedures have varied because of the use of different amylases in attempts to remove starch interference.'Ihe original Bacillus subtilis enzyme Type IIIA … There is a need to standardize the NDF procedure.Procedures have varied because of the use of different amylases in attempts to remove starch interference.'Ihe original Bacillus subtilis enzyme Type IIIA (XIA) no longer is available and has been replaced by a less effective enzyme.For fiber work, a new enzyme' has received AOAC approval and is rapidly displacing other amylases in analyt- ical work.This enzyme is available from Sigma (Number A3306, Sigma Chemical Co., St. Louis, MO).The original publications for NDF and ADF (43, 53) and the Agricultural Handbook 379 (14) are obsolete and of historical interest only.Up to date procedures should be followed.Tnethylene glycol has replaced 2-ethoxyethanol because of reported toxicity.Considerable development in regard to fiber methods has occurred over the past 5 yr because of a redefinition of dietary fiber for man and monogastric animals that includes lignin and all polysaccharides resistant to mammalian digestive enzymes.In addition to NDF, new improved methods for total dietary fiber and nonstarch polysaccharides including pectin and B-glucans now are available.The latter are also of interest in rumen fermentation.Unlike starch.

Nitrogen Metabolism in the Rumen

2005-04-01

À. Bach , S. Calsamiglia , M.D. Stern

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A Nutritional Explanation for Body-Size Patterns of Ruminant and Nonruminant Herbivores

1985-05-01

Montague W. Demment , P.J. Van Soest

The gut capacity of mammalian herbivores increases linearly with body weight. This relationship, coupled with the change in basal metabolism with weight, produces an MR/GC ratio (metabolic requirement/gut capacity) that … The gut capacity of mammalian herbivores increases linearly with body weight. This relationship, coupled with the change in basal metabolism with weight, produces an MR/GC ratio (metabolic requirement/gut capacity) that decreases with increasing body size. Since the retention of a food particle within the gut is proportional to this ratio, the extent to which food particles are digested will be related to body size. Plant material is made up of chemical components that react differently to digestive enzymes. The fiber fraction of plant material (i.e., cell wall) is digested slowly and exclusively by microbial symbiotes. A positive relationship probably exists between the fiber content of plant parts and their biomass in the environment. This relationship is used to describe a resource axis on which digestion rate is the scaling variable. In response to this resource axis and metabolic requirements, the fiber content of the diet of herbivores increases with body size. Ruminants are the predominant medium-sized herbivores in East Africa, while nonruminants are mainly small or very large animals. Small herbivores are constrained to rapid passage of ingesta by their high MR/GC ratio. In response, they have evolved hindgut fermentation and feed selectively on rapidly digestible (i.e., low-fiber) foods. Both responses contribute to loss of nutrients (synthesized by gut microbes) in the feces, and thus contribute to coprophagy in this group. To eat a diet higher in fiber, the herbivore must increase its body size. The reduced MR/GC ratio of medium-sized herbivores allows the evolution of gut structures that selectively delay the passage of ingesta. Selective delay results from the rumination process because the probability of passage is tied to particle size. This process produces more efficient fiber digestion in ruminants than that in nonruminants of similar size. Rumination, however, is advantageous over only a limited range of body sizes. The lower limits of ruminant body size are set by maximal fermentation rates. Foregut fermentation will not only digest the cell wall, but also use many of the soluble nutrients before their direct absorption is possible. Therefore, ruminants must rely almost entirely on the production of microbial volatile fatty acids (VFA) for energy and postruminal digestion of microbes for other nutrients. With decreasing body size, the increasing rate at which energy must be produced per unit volume of the rumen cannot be matched by a concomitant increase in the fermentation rate of forages. Nonruminants are favored by the more efficient energy transfer of enzymatic digestion in the foregut of the low-fiber foods often required by small animals. The upper limits may be imposed by two factors. First, rumination rates (g cell wall ruminated per unit time) increase with body size more slowly than does the cell-wall content of the diet. Using the case of the African buffalo, we arrived at calculations which suggest that sufficient intake of a high-fiber diet cannot be maintained to provide the energy necessary to support larger body sizes. Second, with increased body size the very low MR/GC ratio allows very long retention times. A point in body size is reached (600-1200 kg) at which retention times are sufficient to achieve relatively complete digestion of the potentially digestible component of forages, regardless of whether the herbivore possesses a selective delay mechanism of the rumen or the "perfect mixing" of the nonruminant model. Because of the small body size of early ruminants, the evolution of the rumen was probably initiated by selection for the detoxification or synthetic capabilities of foregut fermentation. The foregut then was preadapted for development as a structure for the selective delay of forages when the grasslands expanded. Changing body size is postulated as a mechanism for differentiating the feeding requirements of herbivores. The fiber composition of plant material is the scaling variable for a resource axis for herbivores. Large herbivores can extract more energy from plant material than can smaller herbivores, but cannot concentrate on the rapidly digestible foods used by small animals because these foods are rare. Therefore, if competition is important in structuring herbivore communities, then body size is probably a factor that contributes to feeding differences.

Prediction of the amount of methane produced by ruminants

1965-02-01

K. L. Blaxter , J. L. Clapperton

An abstract is not available for this content so a preview has been provided. As you have access to this content, a full PDF is available via the 'Save PDF' … An abstract is not available for this content so a preview has been provided. As you have access to this content, a full PDF is available via the 'Save PDF' action button.

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The estimation of the digestibility and metabolizable energy content of ruminant feedingstuffs from the gas production when they are incubated with rumen liquor in vitro

1979-08-01

K. H. Menke , L. Raab , A. Salewski +3 more

SUMMARY A rapid method for measuring gas production during incubation of feedingstuffs with rumen liquor in vitro is described. Gas production in 24 h from 200 mg feed dry matter … SUMMARY A rapid method for measuring gas production during incubation of feedingstuffs with rumen liquor in vitro is described. Gas production in 24 h from 200 mg feed dry matter was well correlated with digestibility of organic matter, determined in vivo with sheep. Multiple regression analysis, when it included data from proximate analysis, resulted in an equation ( R = 0·98) for prediction of metabolizable energy content, based on 30 experiments with rations varying in protein and crude fibre content, and 59 other experiments with concentrates. Energy content was in the range of 7·7–13·2 MJ ME/kg D.M. ( ± S.D. = 11·17 ± 1·08). The residual standard deviation of the equation was 0·25 MJ. Gas production was measured in calibrated syringes. The only chemical determinations needed are dry matter, protein and fat. Differences in activity between batches of rumen liquor are corrected by reference to gas production with standard feedingstuffs (hay meal and maize starch).

The effect of condensed tannins on the nutrition and health of ruminants fed fresh temperate forages: a review

2003-04-01

Byeng R. Min , T. N. Barry , Graeme T. Attwood +1 more

Automated Simultaneous Determination of Ammonia and Total Amino Acids in Ruminal Fluid and In Vitro Media

1980-01-01

G.A. Broderick , Jinhe Kang

Subacute ruminal acidosis in dairy cows: The physiological causes, incidence and consequences

2008-03-11

J.C. Plaizier , Denis O. Krause , G.N. Gozho +1 more

Lipid Metabolism in the Rumen

1993-12-01

T.C. Jenkins

Invited Review: Essential Oils as Modifiers of Rumen Microbial Fermentation

2007-05-21

S. Calsamiglia , Marta Busquet , P. W. Cardozo +2 more

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Carbohydrate and lignin contents of plant materials used in animal feeding

1997-08-01

Knud Erik Bach Knudsen

A TWO‐STAGE TECHNIQUE FOR THE IN VITRO DIGESTION OF FORAGE CROPS

1963-06-01

J. M. A. Tilley , R. A. Terry

A simple technique for the determination in vitro of the dry‐ or organic‐matter digestibility of small (0·5 g) samples of dried forages is described. It involves incubation first with rumen … A simple technique for the determination in vitro of the dry‐ or organic‐matter digestibility of small (0·5 g) samples of dried forages is described. It involves incubation first with rumen liquor and then with acid pepsin. Using 146 samples of grass, clover and lucerne of known in vivo digestibility ( Y ), the regression equation Y = 0·99 X– 1·01 (S.E. ± 2·31) has been calculated, where X = in vitro dry‐matter digestibility. This technique has been used for the study of the digestibilities of plant breeder's material, of the leaf and stem fractions of herbage and of herbage consumed by animals.

Effects and fate of tannins in ruminant animals, adaptation to tannins, and strategies to overcome detrimental effects of feeding tannin-rich feeds

2003-06-30

H.P.S. Makkar

Bovine Acidosis: Implications on Laminitis

1997-05-01

J.E. Nocek

A simple gas production method using a pressure transducer to determine the fermentation kinetics of ruminant feeds

1994-08-01

Michael K. Theodorou , Barbara A. Williams , M.S. Dhanoa +2 more

Creating a System for Meeting the Fiber Requirements of Dairy Cows

1997-07-01

D.R. Mertens

Effects of Diet on Short-Term Regulation of Feed Intake by Lactating Dairy Cattle

2000-07-01

Michael S. Allen

Methane production by ruminants: its contribution to global warming

2000-05-01

Angela R. Moss , Jean-Pierre Jouany , J.R. Newbold

The aim of this paper is to review the role of methane in the global warming scenario and to examine the contribution to atmospheric methane made by enteric fermentation, mainly … The aim of this paper is to review the role of methane in the global warming scenario and to examine the contribution to atmospheric methane made by enteric fermentation, mainly by ruminants.Agricultural emissions of methane in the EU-15 have recently been estimated at 10.2 million tonnes per year and represent the greatest source.Of these, approximately two-thirds come from enteric fermentation and one-third from livestock manure.Fermentation of feeds in the rumen is the largest source of methane from enteric fermentation and this paper considers in detail the reasons for, and the consequences of, the fact that the molar percentage of the different volatile fatty acids produced during fermentation influences the production of methane in the rumen.Acetate and butyrate promote methane production while propionate formation can be considered as a competitive pathway for hydrogen use in the rumen.The many alternative approaches to reducing methane are considered, both in terms of reduction per animal and reduction per unit of animal product.It was concluded that the most promising areas for future research for reducing methanogenesis are the development of new products/delivery systems for anti-methanogenic compounds or alternative electron acceptors in the rumen and reduction in protozoal numbers in the rumen.It is also stressed that the reason ruminants are so important to mankind is that much of the world's biomass is rich in fibre.They can convert this into high quality protein sources (i.e.meat and milk) for human consumption and this will need to be balanced against the concomitant production of methane.methane / ruminants / global warning / reduction strategies Résumé -Production de méthane par les ruminants : sa contribution au réchauffement de la planète.Cet article examine le rôle du méthane dans le processus de réchauffement de la planète et évalue la contribution au méthane atmosphérique des gaz d'origine digestive issus principalement des ruminants.Les émissions annuelles de méthane d'origine agricole dans l'Europe des quinze ont été estimées récemment à 10,2 millions de tonnes et représentent la principale source des entrées

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The Rumen Microbial Ecosystem

1975-11-01

R. E. Hungate

Volatile Fatty Acid Analyses of Blood and Rumen Fluid by Gas Chromatography

1961-09-01

Erica Erwin , Gino J. Marco , E. M. Emery

Effect of ammonia concentration on rumen microbial protein production in vitro

1974-09-01

L.D. Satter , L. L. Slyter

1. The effect of ammonia concentration on microbial protein production was determined in continuous-culture fermentors charged with ruminal contents obtained from steers fed on either a protein-free purified diet, a … 1. The effect of ammonia concentration on microbial protein production was determined in continuous-culture fermentors charged with ruminal contents obtained from steers fed on either a protein-free purified diet, a maize-based all-concentrate diet, or a forage–concentrate (23:77) diet. Urea was infused into the fermentors to maintain various concentrations of ammonia in the incubating mixtures. 2. Under nitrogen-limiting conditions, microbial protein yield measured as tungstic acid-precipitable N (TAPN) increased linearly with supplementary urea until ammonia started to accumulate in the incubating ingesta. Increasing the ammonia concentration beyond 50 mg NH 3 -N/l had no effect on microbial protein production. 3. The molar proportions of volatile acids produced were not affected by the level of urea supplementation. Total acid production was decreased slightly under N-limiting conditions, but not to the same extent as microbial protein production. 4. Estimated yield of microbial dry matter/mol ATP produced averaged 15·6 when non-limiting N as urea was provided with the purified diet. 5. These results suggest that addition of non-protein N supplements to ruminant rations are warranted only if the prevailing concentration of ruminal ammonia is less than 50 mg NH 3 -N/l ruminal fluid.

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The estimation of protein degradability in the rumen from incubation measurements weighted according to rate of passage

1979-04-01

E. R. Ørskov , I. McDonald

Summary A method is proposed for estimating the percentage of dietary protein that is degraded by microbial action in the rumen when protein supplement is added to a specified ration. … Summary A method is proposed for estimating the percentage of dietary protein that is degraded by microbial action in the rumen when protein supplement is added to a specified ration. The potential degradability, p , is measured by incubating the supplement in artificial-fibre bags in the rumen and is related to incubation time, t , by the equation p = a+b (1 – e -ct ). The rate constant k , measuring the passage of the supplement from the rumen to the abomasum, is obtained in a separate experiment in which the supplement is combined with a chromium marker which renders it completely indigestible. The effective percentage degradation, p , of the supplement, allowing for rate of passage, is shown to be p = a +[ bc/(c+k) ] (1- e -(e+k)t ) by time, t , after feeding. As t increases, this tends to the asymptotic value a+bc /( c+k ), which therefore provides an estimate of the degradability of the protein supplement under the specified feeding conditions. The method is illustrated by results obtained with soya-bean meal fed as a supplement to a dried-grass diet for sheep. The incubation measurements showed that 89% of the soya-bean protein disappeared within 24 h and indicated that it was all ultimately degradable with this diet. When the dried grass was given at a restricted level of feeding the allowance for time of retention in the rumen reduced the estimate of final degradability to 71% (69% within 24 h). With ad libitum feeding there was a faster rate of passage and the final degradability was estimated to be 66% (65% within 24 h).

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Investigation of chromium, cerium and cobalt as markers in digesta. Rate of passage studies

1980-07-01

Peter C. Uden , P.E. Colucci , P.J. Van Soest

Abstract A new liquid marker, cobalt‐ethylenediamine tetraacetic acid (EDTA), and two solid markers, chromium (Cr) and cerium (Ce) mordanted plant cell walls, were investigated. Synthesis and methods of analysis are … Abstract A new liquid marker, cobalt‐ethylenediamine tetraacetic acid (EDTA), and two solid markers, chromium (Cr) and cerium (Ce) mordanted plant cell walls, were investigated. Synthesis and methods of analysis are described for the markers. The Cr‐ and Ce‐cell wall complexes were tested for stability to EDTA, hydrochloric acid and rumen microorganisms. Plant cell walls were rendered indigestible by mordanting with Cr and 98% of the marker remained on the fibre after a simulated sequence ( in vitro ) of digestion. Ce‐mordanted cell walls were 35% digestible in vitro using a rumen culture, and 56% of the marker could be washed off the remaining fibre. Treatment with EDTA removed all Ce and 15% of the Cr. Hydrochloric acid (0.01 M ) had a negligible effect on the removal of Cr from the cell walls, whereas 0.1 M acid removed, on average, 10% of the marker. Losses of Cr from the mordant may be related to the quality of the preparation. Co‐EDTA was found to be comparable to Cr‐EDTA. The urinary excretion of Cr and Co was 2–3% in most animals except in rabbits, which excreted as much as 30% of the liquid markers in the urine.

Nutritional management for enteric methane abatement: a review

2008-01-01

K. A. Beauchemin , Michael Kreuzer , F.P. O’Mara +1 more

A variety of nutritional management strategies that reduce enteric methane (CH4) production are discussed. Strategies such as increasing the level of grain in the diet, inclusion of lipids and supplementation … A variety of nutritional management strategies that reduce enteric methane (CH4) production are discussed. Strategies such as increasing the level of grain in the diet, inclusion of lipids and supplementation with ionophores (>24 ppm) are most likely to be implemented by farmers because there is a high probability that they reduce CH4 emissions in addition to improving production efficiency. Improved pasture management, replacing grass silage with maize silage and using legumes hold some promise for CH4 mitigation but as yet their impact is not sufficiently documented. Several new strategies including dietary supplementation with saponins and tannins, selection of yeast cultures and use of fibre-digesting enzymes may mitigate CH4, but these still require extensive research. Most of the studies on reductions in CH4 from ruminants due to diet management are short-term and focussed only on changes in enteric emissions. Future research must examine long-term sustainability of reductions in CH4 production and impacts on the entire farm greenhouse gas budget.

Chapter IV A Roll Tube Method for Cultivation of Strict Anaerobes

1969-01-01

R. E. Hungate

Development of a Comprehensive System of Feed Analyses and its Application to Forages

1967-01-01

P.J. Van Soest

Forage dry matter can be divided into two fractions on the basis of nutritional availability. The first fraction corresponds to the cellular contents and is composed of lipids, soluble carbohydrates, … Forage dry matter can be divided into two fractions on the basis of nutritional availability. The first fraction corresponds to the cellular contents and is composed of lipids, soluble carbohydrates, most protein and other water-soluble matter. This fraction is essentially available, but its digestibility appears incomplete because of the excretion of fecal non-cell-wall matter, which is principally of endogenous and bacterial origin. The second fraction corresponds to the plant cell wall, the availability of which is controlled by structural features that link cellulose, hemicellulose and lignin together. Of the cell-wall components, hemicellulose is a large and variable fraction which prevents crude fiber, cellulose, or lignin from being a good estimator of the content of the plant cell wall. The plant cell wall corresponds to what can be nutritionally denned as a total fiber fraction. The nutritive availability of the cell-wall fraction is not uniform among forages. The dual nutritive character of plant dry matter contraindicates the use of single factors to predict whole dry-matter digestibility.

Evaluation of Acid-Insoluble Ash as a Natural Marker in Ruminant Digestibility Studies

1977-02-01

J. Van Keulen , Bruce A. Young

Comparisons were made of the total fecal collection method and Acid-Insoluble Ash (AIA) natural marker method for determination of dry matter digestibility coefficients of rations by sheep. Three laboratory analytical … Comparisons were made of the total fecal collection method and Acid-Insoluble Ash (AIA) natural marker method for determination of dry matter digestibility coefficients of rations by sheep. Three laboratory analytical procedures [Concentrated (Cone.) HCl, 4N HCl and 2N HCl] which differed in ashing sequence, ashing temperature and acid strength, were used to determine the AIA content of feed and fecal samples. The dry matter digestibility coefficients estimated by the AIA marker method, by all three analytical procedures, were not significantly different from the coefficients determined by the traditional total fecal collection method. However, the digestibility coefficients estimated using the 4N HCl marker were higher (P<.05) than those estimated using the Cone. HCl and 2N HCl markers. The mean and standard deviation of the recoveries of marker in feces estimated using the Cone. HCl and 2N HCl analytical procedures to determine the marker content were 96.7 ± 6.7% and 95.8 ± 6.1%, respectively, and were lower (P<.05) than the recovery (103.0 ± 7.1%) estimated using the 4N HCl procedure. However, none of these measurements of recovery were themselves significantly different from 100% recovery. There was no evidence of a diurnal pattern of AIA excretion which would influence the estimation of digestibility coefficient. The use of natural markers offers some distinct advantages over the total fecal collection method for digestibility studies. In addition to minimal time and labor involvement, quantitative measurements of feed intake and fecal output are not required and measurements can be made on single feed and fecal samples. AIA, therefore, has possible use in digestibility studies and feed testing laboratories where other methods may not be applicable. Of the three AIA analytical procedures evaluated, the 2N HCl procedure was simpler and more convenient than the Cone. HCl or the 4N HCl procedures.

Acidosis in cattle: a review.

1998-01-01

F. N. Owens , D S Secrist , W. J. Hill +1 more

Acute and chronic acidosis, conditions that follow ingestion of excessive amounts of readily fermented carbohydrate, are prominent production problems for ruminants fed diets rich in concentrate. Often occurring during adaptation … Acute and chronic acidosis, conditions that follow ingestion of excessive amounts of readily fermented carbohydrate, are prominent production problems for ruminants fed diets rich in concentrate. Often occurring during adaptation to concentrate-rich diets in feedyards, chronic acidosis may continue during the feeding period. With acute acidosis, ruminal acidity and osmolality increase markedly as acids and glucose accumulate; these can damage the ruminal and intestinal wall, decrease blood pH, and cause dehydration that proves fatal. Laminitis, polioencephalomalacia, and liver abscesses often accompany acidosis. Even after animals recover from a bout of acidosis, nutrient absorption may be retarded. With chronic acidosis, feed intake typically is reduced but variable, and performance is depressed, probably due to hypertonicity of digesta. Acidosis control measures include feed additives that inhibit microbial strains that produce lactate, that stimulate activity of lactate-using bacteria or starch-engulfing ruminal protozoa, and that reduce meal size. Inoculation with microbial strains capable of preventing glucose or lactate accumulation or metabolizing lactate at a low pH should help prevent acidosis. Feeding higher amounts of dietary roughage, processing grains less thoroughly, and limiting the quantity of feed should reduce the incidence of acidosis, but these practices often depress performance and economic efficiency. Continued research concerning grain processing, dietary cation-anion balance, narrow-spectrum antibiotics, glucose or lactate utilizing microbes, and feeding management (limit or program feeding) should yield new methods for reducing the incidence of acute and chronic acidosis.

Nutrient Requirements of Small Ruminants

2007-12-22

National Research Council

Silage review: Interpretation of chemical, microbial, and organoleptic components of silages

2018-04-20

L. Kung , R.D. Shaver , R.J. Grant +1 more

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Use of Detergents in the Analysis of Fibrous Feeds. II. A Rapid Method for the Determination of Fiber and Lignin

1963-10-01

P J Vax Soest

Abstract The capacity of cetyl trimethylammonium bromide to dissolve proteins in acid solution has been utilized in development of a method, called acid-detergent fiber method (ADF), which is not only … Abstract The capacity of cetyl trimethylammonium bromide to dissolve proteins in acid solution has been utilized in development of a method, called acid-detergent fiber method (ADF), which is not only a fiber determination in itself but also the major preparatory step in the determination of lignin. The entire procedure for determining fiber and lignin is considerably more rapid than presently published methods. Compositional studies show ADF to consist chiefly of lignin and polysaccharides. Correlations with the new fiber method and digestibility of 18 forages (r = —0.79) showed it to be somewhat superior to crude fiber (r = —0.73) in estimating nutritive value. The correlation of the new lignin method and digestibility was -0.90 when grass and legume species were separated.

Recent Advances in Animal Nutrition – 1979

1980-01-01

A net carbohydrate and protein system for evaluating cattle diets: I. Ruminal fermentation

1992-11-01

James B. Russell , John D. O’Connor , D. G. Fox +2 more

The Cornell Net Carbohydrate and Protein System (CNCPS) has a kinetic submodel that predicts ruminal fermentation. The ruminal microbial population is divided into bacteria that ferment structural carbohydrate (SO and … The Cornell Net Carbohydrate and Protein System (CNCPS) has a kinetic submodel that predicts ruminal fermentation. The ruminal microbial population is divided into bacteria that ferment structural carbohydrate (SO and those that ferment nonstructural carbohydrate (NSC). Protozoa are accommodated by a decrease in the theoretical maximum growth yield (.50 vs .40 g of cells per gram of carbohydrate fermented), and the yields are adjusted for maintenance requirements (.05 vs .150 g of cell dry weight per gram of carbohydrate fermented per hour for SC and NSC bacteria, respectively). Bacterial yield is decreased when forage NDF is < 20% (2.5% for every 1% decrease in NDF). The SC bacteria utilize only ammonia as a N source, but the NSC bacteria can utilize either ammonia or peptides. The yield of NSC bacteria is enhanced by as much as 18.7% when proteins or peptides are available. The NSC bacteria produce less ammonia when the carbohydrate fermentation (growth) rate is rapid, but 34% of the ammonia production is insensitive to the rate of carbohydrate fermentation. Ammonia production rates are moderated by the rate of peptide and amino acid uptake (.07 g of peptide per gram of cells per hour), and peptides and amino acids can pass out of the rumen if the rate of proteolysis is faster than the rate of peptide utilization. The protein-sparing effect of ionophores is accommodated by decreasing the rate of peptide uptake by 34%. Validation with published data of microbial flow from the rumen gave a regression with a slope of .94 and an r2 of .88.

A Theory of Gradient Analysis

1988-01-01

Cajo J. F. ter Braak , I. Colin Prentice

The Rumen and its Microbes

1966-01-01

Robert E. Hungate

Selenium-Biofortified Alfalfa Hay Supplemented to Jersey and Holstein Dairy Heifers During the Peripartum Period: Effects on Dams and Their Offspring

2025-06-24

Shana Jaaf , Matteo Mezzetti , Sebastiano Busato +2 more | Animals

The objective of the study was to assess whether supplementing dairy heifers with Se-biofortified hay during the last 40 days of pregnancy and early lactation improves performance, metabolism, oxidative status, … The objective of the study was to assess whether supplementing dairy heifers with Se-biofortified hay during the last 40 days of pregnancy and early lactation improves performance, metabolism, oxidative status, and immune response in the dams and their calves. Ten Jersey and eight Holstein pregnant dairy heifers were divided into two groups and supplemented with Se-biofortified or a control alfalfa hay from 40 days before to 2 weeks postpartum. The calves born to the heifers were also monitored during the first month of life. Supplementation of Se-biofortified hay improved milk yield in Holstein heifers only, but had minor effects on blood parameters measured and the liver transcriptome. Similarly, we did not detect any impact of feeding Se-biofortified hay to heifers on their offspring. The data indicated a better immune system and oxidative status in Holstein compared to Jersey heifers. Overall, our data did not support the hypothesis that supplementing Se-biofortified hay to pregnant heifers improves their performance and the health of dams and offspring, at least at the dose we provided.

Differential Rumen Microbial Taxa in Charolais Bulls with Divergent Residual Feed Intake

2025-06-24

Taylor Sidney , Emily Treon , Godstime Taiwo +4 more | Applied Microbiology

The rumen microbiome impacts beef cattle feed efficiency, a key economic factor in production systems. This study investigated the rumen microbiome of Charolais bulls with divergent residual feed intake-expected progeny … The rumen microbiome impacts beef cattle feed efficiency, a key economic factor in production systems. This study investigated the rumen microbiome of Charolais bulls with divergent residual feed intake-expected progeny difference (RFI-EPD) values to identify microbial taxa associated with feed efficiency. Forty Charolais bulls were evaluated for feed intake and growth over 60 days, and RFI values were determined. The 10 most efficient (NegRFI) and 10 least efficient (PosRFI) bulls were selected for microbiome analysis. Rumen fluid samples were collected and analyzed via 16S rRNA gene sequencing. Microbial analysis revealed no significant differences in alpha or beta diversity between groups, but differential abundance analysis identified 20 operational taxonomic units (OTUs) as more prevalent in NegRFI bulls, while 15 OTUs were more abundant in PosRFI bulls. Two OTUs from the key genus Prevotella showed different relative abundances in the two RFI-EPD groups. NegRFI bulls had a higher relative abundance of Prevotella OTU 109358, while PosRFI bulls had more Prevotella OTU 626329. Additionally, OTUs from Ruminococcus, a genus involved in fiber degradation and volatile fatty acid (VFA) production, were more abundant in NegRFI bulls. In contrast, PosRFI bulls had a higher abundance of OTUs from Oscillospira and F16, both linked to butyrate production. The results of this study support the need for further exploration into the role of microbial taxa associated with feed efficiency. A deeper understanding of the functional profile of the microbiota could aid in the development of microbiome-informed strategies to enhance nutrient utilization and performance in beef cattle.

Effects of dietary NDF/NFC ratios on in vitro rumen fermentation, methane emission, and microbial community composition

2025-06-24

Jichao Li , Feng Guan , Pengyu Liu +6 more | Frontiers in Veterinary Science

The objective of this study was to investigate the effects of dietary neutral detergent fiber (NDF) to non-fibrous carbohydrate (NFC) ratios on in vitro rumen fermentation, methane production, and microbiota … The objective of this study was to investigate the effects of dietary neutral detergent fiber (NDF) to non-fibrous carbohydrate (NFC) ratios on in vitro rumen fermentation, methane production, and microbiota in dairy cows. In vitro rumen fermentation was conducted with five dietary groups: R0.48 (NDF/NFC = 0.48), R0.57 (NDF/NFC = 0.57), R0.70 (NDF/NFC = 0.70), R0.90 (NDF/NFC = 0.90), and R1.12 (NDF/NFC = 1.12). As the NDF/NFC ratios increased, total gas production decreased linearly. The degradation rates of dry matter (DM), neutral detergent fiber (NDF), and acid detergent fiber (ADF) decreased, showing a quadratic response ( p = 0.018). Methane production per unit of DM was not significantly affected ( p &gt; 0.05), whereas methane production per unit of degraded DM increased ( p &lt; 0.05). The concentrations of acetate, lactate, and the acetate-to-propionate ratio, as well as pH, increased linearly ( p &lt; 0.05), whereas the concentrations of propionate, isobutyrate, isovalerate, and total volatile fatty acids (TVFA) decreased linearly ( p &lt; 0.05). Microbial crude protein (MCP) production was greater in the low NDF/NFC groups ( p = 0.003). Quantitative real-time PCR analysis revealed that anaerobic fungi were more abundant in the high NDF/NFC groups ( p = 0.001), whereas bacterial and archaeal abundances did not differ significantly among groups ( p &gt; 0.05). Illumina MiSeq PE250 sequencing revealed that the alpha diversity of both bacterial and archaeal communities was influenced by NDF/NFC ( p &lt; 0.05). Principal coordinate analysis further indicated that composition of bacterial ( R 2 = 0.298, p = 0.001) and archaeal ( R 2 = 0.470, p = 0.001) communities differed significantly among groups. Differences in bacterial communities were primarily driven by Firmicutes (e.g., Ruminococcus , Pseudobutyrivibrio ) and Proteobacteria (e.g., Succinivibrio , Ruminobacter ), whereas variations in archaeal communities were associated with Methanobacteriales and Methanomicrobiales. In conclusion, increasing dietary NDF/NFC ratios led to higher methane production per unit of degraded DM, reduced nutrient degradation, and lower TVFA concentrations during in vitro rumen fermentation, accompanied by distinct shifts in bacterial and archaeal community composition.

The effect of the lipase enzyme on rumen metabolism and nutrient absorption in bull calves aged 14–15 months

2025-06-24

Victoria V Grechkina , Е. В. Шейда , Olga Kvan +1 more | Agrarian science

Lipase is an enzyme that is responsible for the breakdown of fats into glycerol and free fatty acids. These products are then absorbed into the gastrointestinal tract of the animal … Lipase is an enzyme that is responsible for the breakdown of fats into glycerol and free fatty acids. These products are then absorbed into the gastrointestinal tract of the animal and are involved in the formation of specific fat compositions for each species, which are then used by the body as an energy source or deposited in the underlying tissues and internal organs. The aim of the study was to study the effect of lipase exoenzyme in dosages of 25 g/t and 50 g/t on rumen metabolism and nutrient absorption in ruminants. The objects of research are cicatricial fluid (RJ) obtained from Kazakh white-headed bull calves with an average weight of 310–320 kg at the age of 14–15 months (4 heads in each group). Exoenzyme preparation: experimental group I — lipase 25 g/t; experimental group II — lipase 50 g/t. With an increase in the concentration of lipase in feed, the level of total nitrogen in the rumen content increases significantly, in the II experimental group this indicator was 99.42 mmol/l, which is 24.55% higher than in the I experimental group and 50.60% (p < 0.05) higher than in the control. The digestibility of dry matter in the first experimental group was higher by 6.09% (p < 0.05), crude protein — by 5.22%, crude fiber — by 6.10% (p < 0.05), as well as the level of assimilation of essential and macronutrients relative to the control group. Thus, lipase is a powerful digestive stimulant for animals. This can affect the growth and development of calves and reduce the cost of feed, as the efficiency of using fat, which is contained in the main raw materials of the diet, increases significantly.

Beef Production Using Presumably "Optimal" Grazing Practices

2025-06-24

| The MIT Press eBooks

Growth performance, carcass traits, and histological changes of goats supplemented with different sources of phytochemicals

2025-06-23

Alaa Emara Rabee , Osama Raef , Ahmed M. Sallam +7 more | Scientific Reports

Phytogenic feed additives are increasingly used to improve animal health and productivity. This study compared the effect of supplementation with tannin to an herbal mixture consisting of ginger, garlic, artemisia, … Phytogenic feed additives are increasingly used to improve animal health and productivity. This study compared the effect of supplementation with tannin to an herbal mixture consisting of ginger, garlic, artemisia, and turmeric on the performance, intestinal parasites, blood metabolites, carcass characteristics, and histology of muscles and intestine of goats. Twenty-seven Shami male goats were assigned to three treatments (n = 9): non-supplemented goats fed a control diet (CC); goats supplemented with 10g /animal/day of quebracho tannins as a source of condensed tannin (TT); and goats supplemented with 10g/animal/day of an herbal mixture (HM). All the animals received a basal diet consisted of concentrate feed mixture and alfalfa hay. The supplementation improved growth performance, nutrients digestibility, and serum immunoglobulins concentration (P < 0.05). The supplementation decreased fecal parasite counts, blood cholesterol, and glutamic-pyruvic transaminase (GPT) enzyme and improved blood glucose (P < 0.05). The supplementation decreased renal and meat fat, and group HM revealed higher polyunsaturated fatty acids and α-Linolenic acid in meat (P < 0.05). Tannin supplementation (TT group) negatively affected the histology of muscles and intestines. The results provide evidence for the beneficial use of an herbal mixture in the diet to improve animal performance, health status, and meat quality in goats.

Elephant grass silage with increasing levels of babassu pie: fermentation parameters and nutritional value

2025-06-23

Rosane Cláudia Rodrigues , Rogério de Paula Lana , Marcônio Martins Rodrigues +7 more | New Zealand Journal of Agricultural Research

Forage Yield of Foxtail Millet (Setaria italica (L.) P. Beauvois) and Its Some Quality and Nutritional Values of Fodder and Silages Obtained from Different Morphological Parts and Silages with Alfalfa (Medicago sativa L.)

2025-06-23

Gülcan Demi̇roğlu Topçu , Sebahattin Boyacı , Hazım Serkan Tenikecier +1 more | Turkish Journal Of Field Crops

The research was carried out in the 2022 and 2023 summer growing seasons in Muğla province, which is under the influence of the Coastal Mediterranean Climate, according to the randomized … The research was carried out in the 2022 and 2023 summer growing seasons in Muğla province, which is under the influence of the Coastal Mediterranean Climate, according to the randomized complete block design with three replications. The 2022 and 2023 summer growing seasons to determine the forage yield of foxtail millet and some of its nutritional values of its fodder and silages, obtained from different morphological parts and in combination with alfalfa. The fresh fodder yield (t ha-1), dry fodder yield (t ha-1), crude ash ratio (%) crude protein ratio (%), dry matter ratio (%), ADF (%), NDF (%), digestible dry matter (DDM, %), dry matter intake (DMI, %), total digestible nutrients (TDN, %), net energy-lactation (Nel, Mcal lb-1), net energy-maintenance (NEm, Mcal lb-1), net energy-gain (Neg, Mcal lb-1), relative feed value (RFV, %), pH, fleig score were determined from dry fodder, silage and foxtail millet-alfalfa silages. The characteristics which were examined in the study determined statistically significant at P˂0.01. Fresh fodder yield and dry fodder yields were varied between 14.50-20.95 t ha-1 and 4.71-7.31 t ha-1 respectively. The highest crude protein ratio (16.76%), dry matter ratio (42.06%), crude ash ratio (7.83%), DDM (67.95%), DMI (2.71%), TDN (65.42%), NEl (0.68 Mcal lb-1 ), NEm (0.73 Mcal lb-1 ) NEg (0.40 Mcal lb-1), RFV (142.92%) and the lowest ADF (26.89%) and NDF (44.23%) were determined from spike of foxtail millets‘s dry fodder. The highest crude protein (14.82%) was determined in silage from leaf, the lowest ADF (38.80%) and NDF (54.76%), the highest TDN (51.73%), DDM (58.67%), DMI (2.20%), Nel (0.52 Mcal lb-1 ), NEm (0.55 Mcal lb-1) and RFV (100.49%) were determined in silage from spike, the highest dry matter ratio (92.61%) was determined in stem, the lowest pH (4.56, 4.93 and 5.92) and the highest flieg score (207.06, 192.53 and 186.49) were determined in whole plant, leaf and spike of foxtail millet silages. The highest crude protein (22.92%), dry matter ratio (93.13%), TDN (60.15%), DDM (64.62%), DMI (2.48%), Nel (0.62 Mcal lb-1), NEm (0.66 Mcal lb-1) and RFV (124.42), the lowest ADF and NDF (31.71% and (48.33%) were determined in %100 alfalfa silage. The highest fleig score (215.27) was determined in 75% Seteria + 25% Alfalfa silage. It can be concluded that; the foxtail millet hay is seen to be sufficient on its own when evaluated in terms of some forage quality aspects and nutritional value. Foxtail millet can be ensiled into reasonable silage, but the quality can be improved with the addition of alfalfa or different legumes or other protein sources.

Lauric acid mitigates heat stress-induced methane emissions and fermentation inefficiency by modulating microbial populations in the rumen of Bach Thao Goat

2025-06-23

Ho Thieu Khoi , Võ Quang Minh , Ho Quang | Journal of Ecological Engineering

Effects of Dietary Ratio of Insoluble Fiber to Soluble Fiber on Reproductive Performance, Biochemical Parameters, and Fecal Microbial Composition of Gestating Sows

2025-06-23

Xiaolu Wen , Qiwen Wu , Kaiguo Gao +4 more | Animals

This study aimed to investigate the effects of dietary ISF:SF ratio on reproductive performance, biochemical parameters, colostrum composition, and fecal microbial composition in gestating sows. A total of 30 multiparous … This study aimed to investigate the effects of dietary ISF:SF ratio on reproductive performance, biochemical parameters, colostrum composition, and fecal microbial composition in gestating sows. A total of 30 multiparous sows were randomly allocated to three dietary treatment groups: 8% inulin diet (ISF:SF 1.14, Inulin group), 8% cotton fiber diet (ISF:SF 6.61, Cotton group), and 4% inulin + 4% cotton fiber diet (ISF:SF 2.37, Inulin + Cotton group). The results showed that, compared to the other groups, the Inulin group had a significantly higher number of piglets born alive, as well as increased plasma concentrations of acetic acid, butyric acid, hexanoic acid, and total short-chain fatty acids (SCFAs) (p < 0.05). Sows in the Inulin group had significantly lower fecal scores than those in the other groups from days 81 to 85 and from days 106 to 110 of gestation (p < 0.05). On day 90 of gestation, the serum levels of albumin, urea, uric acid, calcium, and phosphorus in the Inulin group were significantly lower than those in the other groups (p < 0.05). Additionally, the serum levels of triacylglycerol in the Inulin + Cotton Fiber group were significantly higher than those in the other groups (p < 0.05). However, there were no significant differences in serum concentrations of total protein, creatinine, glucose, cholesterol, HDL-cholesterol, or LDL-cholesterol among the treatments (p > 0.05). On day 110 of gestation, the serum content of urea, uric acid, calcium, and phosphorus in the Inulin group was significantly lower than those in the other groups (p < 0.05). Furthermore, the plasma levels of uric acid, triacylglycerol, and HDL-cholesterol in the Inulin + Cotton Fiber group were significantly higher than those in the Cotton Fiber group (p < 0.05), while the creatinine levels in the Inulin group were higher than those in the other groups (p < 0.05). No differences were observed in the composition and immune performance of colostrum (p > 0.05). Microbial sequencing analysis showed that dietary inulin supplementation to increase the proportion of soluble fiber significantly decreased the abundance of Firmicutes, Clostridia, Clostridiales, Lachnospiraceae, Streptococcaceae, and Streptococcus (p < 0.05). The abundance of short-chain fatty acid-producing microorganisms—Bacteroidetes, Bacteroidia, Bacteroidales, and Muribaculaceae—was significantly increased (p < 0.05). The results indicated that inulin supplementation decreased the dietary ISF:SF ratio, significantly alleviated constipation in sows, increased the number of piglets born alive, regulated intestinal microecology, and increased the plasma concentrations of short-chain fatty acids (SCFAs), including acetic, propionic, and butyric acids.

The Effects of Trace Mineral Source, Diet Type, and Monensin and Tylosin on Rumen Fermentation Characteristics in Beef Cattle

2025-06-23

Joyce O Graziella , Huey Yi Loh , Cindy Muco +3 more | Biological Trace Element Research

Sixteen Angus crossbred steers were used to determine the impact of trace mineral (TM) source, diet type, and monensin and tylosin supplementation on rumen fermentation characteristics. Experiment 1: Steers were … Sixteen Angus crossbred steers were used to determine the impact of trace mineral (TM) source, diet type, and monensin and tylosin supplementation on rumen fermentation characteristics. Experiment 1: Steers were adapted to a finishing diet before being assigned dietary treatments. A 2 × 2 factorial arrangement of treatments was utilized with factors: (1) TM source (sulfate; STM or hydroxy; HTM) and (2) with or without monensin and tylosin (MT). Following the 28-day feeding period, rumen samples were collected at 0, 2, and 4 h post-feeding. Experiment 2: Steers were adapted to a lactating dairy cow diet and assigned dietary treatments for 28 days. A 2 × 2 factorial arrangement of treatments was utilized. Factors included (1) TM source (STM or HTM) and (2) with or without monensin (M). On day 29, rumen samples were collected at 0, 2, and 4 h post-feeding. Rumen fluid samples from both experiments were analyzed for short chain fatty acids (SCFA), pH, and ammonia concentrations. Experiment 1: Molar proportions of acetate were lesser (P < 0.04) and propionate greater (P < 0.01) in steers receiving HTM compared to steers receiving STM. Experiment 2: Total SCFA production was greater (P < 0.01) in steers supplemented with HTM compared to STM. Supplementation of M reduced the molar proportion (P < 0.01) of acetate and increased (P < 0.05) molar proportions of propionate and butyrate. These data indicate that TM source and M may modulate rumen fermentation characteristics but their impacts on rumen fermentation may be diet dependent.

Plantain-mixed pasture collected in different climatic seasons produced less methane and ammonia than ryegrass–white clover pasture in vitro

2025-06-23

Komahan Sivanandarajah , D. J. Donaghy , G. Molano +5 more | Animal Production Science

Context Plantain (PL) is recognised for reducing nitrate leaching and nitrous oxide emissions in pastoral systems. Evidence has shown that cows fed pure PL produced less methane (CH4) than cows … Context Plantain (PL) is recognised for reducing nitrate leaching and nitrous oxide emissions in pastoral systems. Evidence has shown that cows fed pure PL produced less methane (CH4) than cows fed ryegrass. However, it is unclear if the CH4 reduction can be achieved with PL in mixed pasture. Aim The study evaluated the in vitro rumen fermentation profiles of ryegrass–white clover (RWC) and medium-level PL (PLM, containing ~40% PL) pasture collected during different climatic seasons, to determine whether this inclusion level influences CH4 and rumen ammonia (NH3) production. Methods Substrates were selected from samples with various proportions of PL. Samples were categorised into three climatic seasons (i.e. spring, summer and autumn) and two pasture types (PLM and RWC). Representative samples for these scenarios were tested in an automated in vitro rumen batch culture system for gas, CH4 (mL/g DM) and NH3 (mM/g DM) production. Key results In summer samples, PLM produced approximately 8%, 14% and 19% less CH4 at 12 h, 24 h and potential CH4 production (PCH4), respectively. Although gas production (GP) was similar at 12 and 24 h, PLM had 13% lower potential GP than RWC (P < 0.05). In spring samples, PLM had approximately 11% greater GP and CH4 production at 12 h. For the autumn samples, GP and CH4 production were similar between PLM and RWC (P > 0.05). Net NH3 production from PLM substrates was significantly lower in spring (27%) and autumn (17%) samples, with no differences in summer, despite higher crude protein levels in the selected PLM. Conclusions Compared with RWC, PLM changed rumen fermentation parameters that could translate to potential environmental benefits: PLM produced less net NH3 in spring and autumn samples (27% and 17%, respectively), and up to 19% less CH4 production in summer samples. Implications Incorporating ~40% PL into RWC pasture showed a promising reduction of CH4 emissions and nitrogen losses in vitro. If the in vitro results translate to cows grazing pasture, this could offer greater environmental benefits with minimal input costs. In vitro results suggest that PLM’s potential to mitigate CH4 emissions can be influenced by seasonal variations in pasture quality compared with RWC. However, further animal studies are needed to fully comprehend the CH4 mitigation potential of this forage.

The Modification of Dairy Cow Rations with Feed Additives Mitigates Methane Production and Reduces Nitrate Content During In Vitro Ruminal Fermentation

2025-06-23

Everaldo Attard , Jamie Buttigieg , K. Simeonidis +1 more | Gases

This study evaluated the effects of feedstuffs and additives in dairy cow rations on rumen methane production and nitrate content in groundwater. Two basal rations and their supplements were analyzed … This study evaluated the effects of feedstuffs and additives in dairy cow rations on rumen methane production and nitrate content in groundwater. Two basal rations and their supplements were analyzed in regard to proximate parameters, and an in vitro rumen fermentation system assessed methane release and nitrate levels over 72 h. Supplementing dairy cow rations with Brassica rapa (BR) boosted the ether extract content, while silage produced the highest amount of methane. Rapidly degrading substrates like BR and ground maize produced methane faster, but in smaller amounts, than straw and silage. BR, Opuntia ficus-indica (OFI), and Posidonia oceanica (PO)-supplemented rations had mixed effects; PO reduced the methane yield, while OFI increased methane production rates. BR-supplemented rations had the lowest nitrate levels, making it suitable for anaerobic digestion. The multivariate analysis showed strong correlations between crude protein, dry matter, and ash, while high-nitrate substrates inhibited methane production, supporting the literature on the role of nitrates in reducing methanogenesis. These results emphasize the need to balance nutrient composition and methane mitigation strategies in dairy cow ration formulations.

Enterobacter spp. inhibits AFB1 production in corn silage through carbohydrates competition under rust infection

2025-06-23

Luo chongyu , Yang Xin , Chen huilong +7 more | Chemical and Biological Technologies in Agriculture

The in vitro energy and enteric methane values of three microalgae species for ruminants

2025-06-23

Nagehan Nur Altan , Muazzez Cömert Acar | Ege Üniversitesi Ziraat Fakültesi Dergisi

Objective: The aim of the study was to determine the in vitro energy and enteric methane values of the three microalgae (Spirulina platensis (SPTS), Chlorella vulgaris (CVGS) and Schizochytrium spp. … Objective: The aim of the study was to determine the in vitro energy and enteric methane values of the three microalgae (Spirulina platensis (SPTS), Chlorella vulgaris (CVGS) and Schizochytrium spp. (SSPP) species by in vitro Gas Production Technique. Materials and Method: The gas production (GP) of the microalgae were found based on 3, 6, 9, 12, 24, 48 and 72 hours incubation period. The IVOMD (In Vitro Organic Matter Digestibility), ME (Metabolic Energy) and NEL (Net Energy Lactation) values were calculated by using 24-hours gas production and some crude nutrient contents. The CH4VFA (Methane volatile fatty acids) were found from volatile fatty acids (VFA) profiles of 48-hours of incubation residues. Results: For each microalgae, the differences between the IVOMD and NEL values were significant (P&lt;0.05). The differences between IVOMD and NEL values were similar in SPTS and CVGS which were significantly higher than SSPP (31.10 DM% , 1010 kcal/kg) (P&lt;0.05). The ∑VFA and CH4 VFA were found to be highest in CVGS and similar to each other in SPTS and SSPP. Although the CH4VFA values of SPTS and SPSS were similar to each other, the CH4VFA value of SSPP (0.70 mol/mol VFA) was found to be the lowest. Conclusion: If it is produced economically, it may be recommended that CVGS can be used as an alternative feed source in ruminant nutrition due to high energy, crude protein and ∑VFA concentrations, while SPTS and SSPP can be used as feed additives due to their low ∑VFA and CH4VFA concentrations.

Understanding the impacts of intensity and harvest frequency on <scp>Tithonia diversifolia</scp> for use in tropical silvopastoral systems

2025-06-22

Vagner Ovani , Simón Pérez‐Márquez , Alyce Monteiro +7 more | Grassland Science

Abstract Tithonia diversifolia (Hemsl.) A. Gray has significant potential as a forage source in silvopastoral systems, particularly in tropical conditions. However, its intensity and frequency management differ from those commonly … Abstract Tithonia diversifolia (Hemsl.) A. Gray has significant potential as a forage source in silvopastoral systems, particularly in tropical conditions. However, its intensity and frequency management differ from those commonly applied to grasses. This study aims to evaluate T. diversifolia under two harvest intensities (30 and 40 cm stubble height) and four harvest frequencies (21, 28, 35 and 42 days), aligning with Brazil's traditional tropical grass management practices. Biomass production and nutritive value of forage, as well as in vitro rumen fermentation parameters, were assessed. We observed that the tested harvest intensities have a limited impact on the biomass production and nutritional value of T. diversifolia . Despite the linear increase in biomass production, lower harvest frequencies (i.e., longer regrowth period) significantly affect nutritional value, impacting the products of ruminal fermentation, as indicated by the in vitro assay. The methane production per gram of degraded organic matter (OM) and the OM allocated for microbial biomass production are affected by the harvest frequencies. Additionally, we observed that rainfall and canopy height have a stronger correlation with biomass production than harvest frequencies controlled by days. We conclude that T. diversifolia is minimally affected by harvest intensities and, for Brazilian edaphoclimatic conditions, it can be harvested with higher frequencies than those suggested for other regions.

Transforming forage nutrition: Advances in silage additives for enhanced preservation and feed quality

2025-06-21

U Srinivas Reddy , T Selvakumar , K. R. V. Sathyasheela +2 more | Plant Science Today

Global demand for livestock products increases the need for high-quality fodder. However, urbanization resulted in the depletion of agricultural lands expanding the demand for food, feed and fodder. To overcome … Global demand for livestock products increases the need for high-quality fodder. However, urbanization resulted in the depletion of agricultural lands expanding the demand for food, feed and fodder. To overcome this issue, the available fodder and agricultural wastes are preserved anaerobically to feed animals. This efficient process of preserving the fodder anaerobically throughout the year is known as ensiling and the preserved fodder is known as silage. To improve the quality and longevity of silage, various additives such as microbial inoculants (bacterial inoculants, yeast), enzymes, chemical additives (organic and mineral acids), nutrients (urea, ammonia, sodium chloride, sodium di acetate) and fermentation accelerators (molasses, starchy substance, grains) are added. Addition of these additives reduces pH to below 4.2, proteolysis up to 40 %, ammonia volatilization, population of yeasts, molds and enhances fermentation, improves the aerobic stability by 2-5 days, optimizes nutrient retention and quality of silage. By supporting better livestock nutrition, silage additives increase 5 to 20% milk production, lactation period and promote beneficial microbial populations in the rumen of cattle. This review describes the usage and effectiveness of various additives that are used to enhance the silage quality in terms of storage and nutritional content.

Lactational Performance of Early-Lactation Dairy Cows Fed Forages Produced by Two Different Crop Production Programs

2025-06-21

D. P. Casper , J. P. Pretz , Cliff Ramsier | Animals

Early-lactation high-producing dairy cows require highly digestible forages. Thirty early-lactation (58 days in milk; 38.9 kg/d milk) cows were blocked and randomly assigned to one of two treatments. The treatments … Early-lactation high-producing dairy cows require highly digestible forages. Thirty early-lactation (58 days in milk; 38.9 kg/d milk) cows were blocked and randomly assigned to one of two treatments. The treatments were the control (CON), consisting of corn silage and alfalfa haylage produced via university crop production practices, versus supplementing soil and crop additives (SCA) during crop production. Milk production (32.6 and 36.9 kg/d for CON and SCA, respectively) increased (p < 0.04) when cows were fed SCA forages compared with cows fed CON forages, while the dry matter intakes were similar (p < 0.46). The yields of milk fat were similar (p > 0.26), but the milk protein (0.98 and 1.09 kg/d), lactose (1.62 and 1.88 kg/d), and total solids (3.77 and 4.25 kg/d) contents were greater (p < 0.05) for cows fed SCA compared with cows fed CON. The total-tract apparent neutral detergent fiber (48.5 and 54.7%) and acid detergent fiber (48.3 and 54.4%) digestibility increased (p < 0.03), while the starch digestibility (97.9 and 98.4%) tended (p < 0.06) to increase for cows fed SCA compared with cows fed CON. Feeding highly digestible forages during early lactation improved milk production, milk composition, and fiber digestibility in a high-forage ration.

Effect of Inoculation with Lactiplantibacillus plantarum and Cellulase on the Quality of Mulberry Silage

2025-06-20

Yingchao Sun , Yongcheng Chen , Zhi-Wei Huo +5 more | Microorganisms

Lactic acid bacteria (LAB) and cellulase have been used as additives to improve the fermentation quality of mulberry silage. This study investigated the dynamics of fermentation characteristics and bacterial communities … Lactic acid bacteria (LAB) and cellulase have been used as additives to improve the fermentation quality of mulberry silage. This study investigated the dynamics of fermentation characteristics and bacterial communities during 60-day ensiling through three established treatment groups: Control (no inoculation), Lactiplantibacillus plantarum (LP) inoculation as well as combination of L. plantarum and cellulase inoculation group (LPC). The results showed that compared with the Control group, the LP and LPC treatments significantly reduced the loss of dry matter, soluble carbohydrates, and crude protein (p < 0.05), effectively promoted the accumulation of lactic acid and acetic acid (p < 0.05), but significantly elevated ammonia nitrogen (NH3-N) production. Inoculation was beneficial to the stability of the bacterial community in mulberry branch and leaf silage because it can maintain a high level of beneficial bacteria (Lactiplantibacillus) and inhibit the growth of harmful bacteria (Escherichia-Shigella). The combination of the inoculation of L. plantarum and cellulase may improve the quality of mulberry branch silage.

Effect of Adding Alkaline Metal Ions Complexes Rumen Microbiota and Metabolome of Hu Lambs

2025-06-19

Mingyue Li , Chi Ma , Yalin Li +5 more | Animals

This study aimed to evaluate the effects of studying the effects of the alkali metal ion complexes (AMIC) on the rumen of lambs. Eighteen 3-month-old male Hu lambs (30 ± … This study aimed to evaluate the effects of studying the effects of the alkali metal ion complexes (AMIC) on the rumen of lambs. Eighteen 3-month-old male Hu lambs (30 ± 2.5 kg) were randomly assigned to three groups (n = 6). Dietary treatments were: control group (CG, base diet), group C1 (base diet + 0.15% AMIC), and group C2 (base diet + 0.30% AMIC). After 60 days of feeding, samples were collected for analysis. Compared with CG, rumen weight significantly increased in both C1 and C2 (p < 0.05). In C2, average daily gain (ADG), bacterial crude protein (BCP), propionic acid concentration, and rumen papillary length were significantly higher than in CG (p < 0.05). Rumen microbiota analysis showed that AMIC supplementation changed the microbial community composition, increasing the relative abundance of fiber-degrading bacteria (e.g., Prevotellaceae_UCG-001) and decreasing pathogenic Proteobacteria. In particular, rumen papillary length positively correlated with Unclassified Oscillospiraceae, Candidatus Saccharimonas, and Unclassified Clostridia vadinBB60 group. Metabolomic analysis revealed that quercetin 3-O-glucuronide levels increased in a dose-dependent manner with higher AMIC. This metabolite positively correlated with Prevotellaceae_UCG-001 abundance and ADG. At 0.30% AMIC, phospholipids PC(18:0/18:4(6Z,9Z,12Z,15Z)) and PE(18:0/16:1(9Z)) were significantly upregulated, and both positively correlated with Candidatus Saccharimonas, Unclassified Clostridia vadinBB60 group, and papillary morphology. In summary, AMIC supplementation affected metabolism by modulating the rumen microbiota, thereby promoting energy absorption and growth. The 0.30% AMIC inclusion significantly enhanced rumen papilla growth, increased the absorption area, promoted propionic acid production, reduced the acetic acid to propionic acid ratio, and ultimately improved the growth rate of Hu lambs. Thus, adding 0.30% AMIC was associated with improved growth performance.

Ruminantlarda Rumenin Önemi

2025-06-19

Süleyman Hacısalihoğlu , İbrahim Sadi Çetingül | Harran Üniversitesi Veteriner Fakültesi Dergisi

Çalışmada ruminantların rumenlerinin bu hayvanlar için ne kadar önemli olduğunu ortaya koymak amaçlanmıştır. Ruminantlardan elde edilen süt ve et insanların beslenme kaynakları açısından oldukça önemlidir. Ruminantların ön midelerinden olan rumen … Çalışmada ruminantların rumenlerinin bu hayvanlar için ne kadar önemli olduğunu ortaya koymak amaçlanmıştır. Ruminantlardan elde edilen süt ve et insanların beslenme kaynakları açısından oldukça önemlidir. Ruminantların ön midelerinden olan rumen ruminantlar için çok önemlidir. Fakat ruminantların doğduklarında rumenleri faaliyet gösterememektedir. Rumen içerisindeki mikroorganizmalar ile birlikte ruminantlar selüloz gibi maddeleri sindirebilirler. Rumen mikroorganizmaları tüm gıdaların sindirim faaliyetleri neticesinde ruminantların büyük ölçüde enerji ihtiyacını sağlayan Uçucu Yağ Asitlerine (UYA) dönüşürler. Ayrıca azot kaynakları da rumen mikroorganizmalarının faaliyetleri sonrasında mikrobiyel proteinlere dönüştürülmektedir. Rumen mikroorganizmaları B grubu vitaminleri de sentezleyerek ruminantların faydalanmasını sağlamaktadır. Rumen mikroorganizmaların yasayabilmeleri için rumenin içerisinin dengede kalması gerekir. Rumenin içerisinin sıcaklık, besin, pH gibi değerliliklerinin standart aralıklarda tutulmalıdır. Rasyonlarda bulunan yemlere ek olarak rasyona canlı mikroorganizmalar ve aromatik yağlar gibi katkı maddeleri eklemek rumen standartlarını sağlamaya yardımcı olur. Rumen içerisine yerleştirilen sensörlerle rumenin pH, sıcaklık gibi değerlerin anlık ölçümleri yapılabilmektedir. Böylece hayvanlar sürekli gözlem altında tutularak daha sağlıklı ve verimli yetiştirilmektedir.

Effects of amount and frequency of nitrogen supplementation on nutritional performance and metabolism in cattle fed medium-quality tropical forage

2025-06-19

Luana Marta de Almeida Rufino , João Paulo Pacheco Rodrigues , Marcia Franco +4 more | Deleted Journal

Effects of Dietary Protein Level during Transition Period on the Performance of Crossbred Heifers

2025-06-19

S. Zaman , Raj Jyoti Deka , D Barua +3 more | International Journal of Bio-resource and Stress Management

This study was carried out from August to September, 2019 at Instructional Livestock Farm (Cattle) under Department of Livestock Production and Management, College of Veterinary Science, Assam Agricultural University, Khanapara, … This study was carried out from August to September, 2019 at Instructional Livestock Farm (Cattle) under Department of Livestock Production and Management, College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati (781 022), Assam, India to study the production performance of crossbred heifers during transition period. Twelve pregnant crossbred heifers were selected in advance stage of pregnancy and were divided into two groups 21 days prior to calving viz., Treatment No. 1 (T1) and Treatment No. 2 (T2) consisting six animals in each group. Since 21 days prior to calving, the T1 group was provided concentrate ration having 18% CP and 70% TDN and the T2 group was provided concentrate ration having 22% CP and 70% TDN during the transition period. It was observed that the overall average daily DM intake during pre-partum did not show significant difference due to dietary protein level but during postpartum there was significant difference between the two level of dietary protein. The overall DM intake during postpartum was (10.92±0.27 kg) was significantly higher than pre-partum (6.85±0.16 kg) which might be due to milk production. The average birth weight of calves was not differing significantly. The overall average total blood protein and blood calcium concentration did not show significant difference due to dietary protein level, but there was significant difference between pre-partum and postpartum period. The overall average daily colostrum yield was apparently higher but not significantly higher in T2 than T1 group. From the present study it can be concluded that feeding crossbred heifers with higher dietary protein during transition period improved their production performance.

Live yeast supplementation improves apparent nutrient digestibility of high-fibre diet in mature quarter horses

2025-06-18

Silvia Sandrini , Vera Perricone , A. Pe∫a +4 more | Italian Journal of Animal Science

The Effects of Jojoba Meal Supplementation on the Performance and Health of Nursing Awassi Ewes and the Pre-Weaning Growth of Their Lambs

2025-06-18

Ja’far Al-Khaza’leh , Belal S. Obeidat | Dairy

Utilizing agro-industrial by-products to feed livestock is crucial for environmental protection and, simultaneously, lowering production and feeding costs. In light of these aims, in this study, two trials were conducted … Utilizing agro-industrial by-products to feed livestock is crucial for environmental protection and, simultaneously, lowering production and feeding costs. In light of these aims, in this study, two trials were conducted to evaluate the impact of jojoba meal (JJM) on Awassi ewes’ milk properties, nutrient intake, digestibility, and the pre-weaning growth of their nursing lambs. In the first trial, 22 Awassi ewes were divided equally between two experimental diets at random (11 ewes per diet): 0% JJM (CON) and 15% JJM (JJM15) of dietary dry matter (DM). In the second trial, 10 ewes were randomly selected (5 ewes/diet) to assess nutritional digestibility and N balance. The results of trial 1 showed that neutral detergent fiber (NDF), acid detergent fiber (ADF), and ether extract (EE) intake values were greater (p ≤ 0.02) in the JJM15 group compared to the CON group. The total gain and average daily gain (ADG) of the lambs in the JJM15 group were significantly higher compared to those of the CON group (p < 0.05). The average milk yield of nursing ewes was similar between the two dietary groups (p ˃ 0.05). The percentage and yield of solids-not-fat (SNF) in the JJM15 group were significantly higher compared to the CON group. The other milk components, including protein, lactose, fat, and total solids yields, were similar between the dietary groups (p ˃ 0.05). The milk production cost was significantly lower for the JJM15 diet than the CON diet (p = 0.004). Triglyceride levels were lower (p = 0.001) in the JJM15 diet group than in the CON diet group. In trial 2, nutrient digestibility and N balance were not affected (p ≥ 0.073) by the consumption of JJM15. In conclusion, JJM at 15% of dietary DM resulted in no negative effects on the health, performance, or milk quality of Awassi ewes. Most significantly, by lowering the cost of production, our results appear to indicate that this dietary supplement improves economic efficiency.

Multi-omics insights into key microorganisms and metabolites in Tibetan sheep’s high-altitude adaptation

2025-06-18

Jing Wang , Jianbin Liu , Tingting Guo +5 more | Frontiers in Microbiology

Tibetan sheep gastrointestinal microbial communities and metabolites showed adaptive differences with altitude, but we do not know which flora or metabolites may play an important role in acclimatization to the … Tibetan sheep gastrointestinal microbial communities and metabolites showed adaptive differences with altitude, but we do not know which flora or metabolites may play an important role in acclimatization to the altitude environment. Therefore, we systematically analyzed the microbial structure and metabolites in the rumen and feces of Tibetan sheep at two altitudes (4,424 m and 2,364 m) using amplicon sequencing and untargeted metabolomics. The results showed that the bacterial communities differed greatly between the two groups, with high altitude Tibetan sheep having a higher forage fermentation capacity, and the abundance of some bacteria and fungi that were conducive to the decomposition of cellulose in rumen fluid increased significantly (especially Bacteroidota, Neocallimastigomycota, and Ascomycota), and the short chain fatty acids and NH 3 -N produced by metabolism also increased. There was also a significant increase in the abundance of Naganishia, which is prone to survive in extreme environments. In addition, the metabolite profiles in the rumen and feces of Tibetan sheep at two altitudes were also significantly different, and further correlation analysis showed that the differential bacteria in the rumen were mainly related to the products related to amino acid metabolism and lipid metabolism, and the differential bacteria in the feces were mainly correlated with some metabolites related to antibacterial, anti-inflammatory, anti-tumor and other disease treatment components. Collectively, these changes in microbiota and metabolites may have facilitated the adaptation of Tibetan sheep to the harsh plateau environment, contributing to their better survival and reproduction. This study provides a basis for research on the mechanisms of adaptation of Tibetan sheep to the plateau environment.

Biomass production and chemical composition of corn for silage in different reproductive stages

2025-06-18

Everton Luiz Carneiro Pereira , Mikael Neumann , Ellen Baldissera +7 more | Semina Ciências Agrárias

The ongoing professionalization of corn silage production is related to the specific productive and qualitative agronomic characteristics of the different hybrids available on the market, which define the dynamics of … The ongoing professionalization of corn silage production is related to the specific productive and qualitative agronomic characteristics of the different hybrids available on the market, which define the dynamics of the appropriate moment for harvesting and making silage. This experiment evaluated the morphological and chemical composition, dry biomass production, and rumen degradation of plants from different corn hybrids, harvested at various reproductive stages. The experimental design was randomized blocks, in a 3 x 21 and/or 8 factorial arrangements, with three corn hybrids (B2401PWU, B2782PWU, and B2801PWU) associated with 21 and/or 8 harvest times, to evaluate productive and chemical parameters, respectively, at regular intervals, between the R1 and R6 reproductive stages, with four repetitions each. Changes in the reproductive cycle increased the production of dry biomass of forage and grains up to R5, reaching 26,536 and 10,142 kg.ha-1, respectively. This resulted in reduced average costs, reaching values of 0.51 R$ kg.DM-1. As the reproductive cycle advanced, there was a greater participation of grains and a dilution of structural components, resulting in reductions in NDF (44.44%) and ADF (27.66%) at R5. At this stage, the plant showed an average DM of 30%, while the grains had a DM of 56%. In situ degradability values were higher at the R4-R5 transition stage, while other chemical parameters were higher at R5 and/or before reaching physiological maturity at R6. In addition to the reproductive stages described in the literature, the transition stages are also relevant due to the physiological changes in the plant that affect the productivity and chemical quality of corn plants used for silage production.

Substituição do fubá de milho por farelo de palma forrageira em dietas de bezerras leiteiras: avaliação produtiva e econômica

2025-06-18

Fernando da Silva Rocha , Patrícia Araújo dos Santos , Heloísa Thereza Ribeiro Fonseca +6 more | Semina Ciências Agrárias

O objetivo com o estudo foi avaliar o desempenho produtivo e a viabilidade econômica da substituição do fubá de milho (FM) pelo farelo de palma (FP) em dietas para bezerras … O objetivo com o estudo foi avaliar o desempenho produtivo e a viabilidade econômica da substituição do fubá de milho (FM) pelo farelo de palma (FP) em dietas para bezerras leiteiras. O experimento foi conduzido em delineamento experimental inteiramente casualizado com quatro tratamentos e seis repetições. Foram utilizadas 24 bezerras desmamadas 5/8 Girolando com peso corporal médio de 98,5 ± 16,88 kg e idade média de 131 dias. Os tratamentos experimentais consistiram na inclusão do FP em 0, 12, 22 e 32% da dieta total. Foram avaliados a ingestão de matéria seca (IMS) das dietas experimentais, ganho de peso médio diário (GMD) dos animais e o custo alimentar. A digestibilidade in vitro da matéria seca (DIVMS) dos suplementos concentrados também foi determinada. A DIVMS reduziu linearmente de 89,39 para 81,96% entre 0 e 32% de inclusão do FP. Não houve efeito da substituição do FM pelo FP sobre o peso final, GMD e IMS, que apresentaram médias de 162,04 kg; 0,802 kg dia-1 e 3,42 kg dia-1, respectivamente. O custo do ganho de peso foi de $1,14, $1,09, $ 1,04, e $ 1,27 para os grupos 0, 12, 22 e 32% FP, respectivamente. A substituição do FM por FP em até 32% da dieta não altera o ganho de peso dos animais e a inclusão de 22% de FP é a mais vantajosa economicamente.

Potencial de un fitobiótico a base de Acacia concinna y el alga roja Palmaria palmata para reducir la producción ruminal de metano in vitro

2025-06-18

Oscar Ponce-Pérez , Germán David Mendoza Martínez , Pedro Abel Hernández-García +5 more | Revista Mexicana de Ciencias Pecuarias

Los cambios en la producción de metano y dióxido de carbono y sus efectos sobre la microbiota ruminal se evaluaron in vitro mediante la incubación de alfalfa con un aditivo … Los cambios en la producción de metano y dióxido de carbono y sus efectos sobre la microbiota ruminal se evaluaron in vitro mediante la incubación de alfalfa con un aditivo herbal formulado con Acacia concinna y con un suplemento que contenía el alga roja Palmaria palmata. Se caracterizaron los metabolitos del suplemento con Palmaria palmata y se encontraron 20 compuestos químicos, entre los que se destacaron fenoles, terpenos, compuestos halogenados y alcanos. La inclusión del aditivo herbal redujo (P<0.01) el metano ruminal en un 29 % y el alga roja en un 56 %. La concentración molar de ácidos grasos volátiles (AGV) aumentó (P<0.05) con el aditivo de algas marinas. Los dos aditivos aumentaron las proporciones de acetato y propionato y redujeron la de butirato (P<0.05) en comparación con el control. No se detectaron diferencias (P>0.05) en la abundancia de la mayoría de las familias microbianas, solo cambios menores en Rikenellaceae; únicamente Cellulomonadaceae aumentó significativamente (P>0.001) con el aditivo herbal. Los dos aditivos mostraron un potencial reductor de metano, que fue más pronunciado para Palmaria palmata.

Production and nutrient use efficiency of lactating dairy cows fed concentrate feeds via an automatic feeding system

2025-06-18

L.F. Martins , S.F. Cueva , Derek Wasson +4 more | Journal of Dairy Science

Effects of replacing canola meal with extruded soybean meals on lactational performance and enteric gas emissions in dairy cows

2025-06-18

S.F. Cueva , L.F. Martins , D.E. Wasson +4 more | Journal of Dairy Science

Mixed cereal silage as a forage complement to Kikuyu grass grazing for small-scale dairy systems in the dry season

2025-06-17

Sirley Carrillo-Hernández , José Velarde-Guillén , Felipe López-González +1 more | Tropical Animal Health and Production

Untargeted metabolomics unveils an accumulation of flavonoids associated with the microbiome of low-performing sorghum

2025-06-17

Ciara Garcia , Duke Pauli , A. Elizabeth Arnold | Discover Plants.

Productive and Qualitative Characteristics of Pasture and Performance of Sheep Grazing on Urochloa Cultivars Under Intermittent Stocking

2025-06-17

Rodrigo da Silva Santos , João Virgínio Emerenciano Neto , Stela Antas Urbano +7 more | Animals

This study aimed to evaluate the structural, productive, and qualitative characteristics of forage, as well as the performance of sheep grazing on Urochloa pastures. Santa Inês sheep were used in … This study aimed to evaluate the structural, productive, and qualitative characteristics of forage, as well as the performance of sheep grazing on Urochloa pastures. Santa Inês sheep were used in a completely randomized design, with six experimental units per treatment. Treatments comprised four Urochloa cultivars (Marandu, Paiaguás, Xaraés, and Ipyporã) managed under intermittent stocking. Grazing and rest periods did not differ among cultivars, averaging 9.9 and 43.5 days, respectively. Pre-grazing forage mass was higher in the Ipyporã cultivar than the others, which did not differ from one another (4670.3 kg DM/ha). The leaf blade-to-stem ratio at pre-grazing was lowest in Paiaguás (1.09) and highest in Xaraés (1.61). Mineral matter, acid detergent fiber, and crude protein contents in leaves did not differ among cultivars. The longest grazing time was observed in Paiaguás (370.8 min/day). Cultivar did not affect idling time (592.1 min/day), rumination time (466.9 min/day), or bite rate (19.95 bites/min). Average daily gain did not differ among cultivars, with an overall mean of 74.5 g/day. The stocking rate was higher in Ipyporã compared to the other cultivars (12.75 AU 30 kg/ha), resulting in greater animal gain per unit area (1319.5 g/ha). The Ipyporã cultivar was more productive and supported a higher carrying capacity. Nonetheless, all four cultivars yielded satisfactory results and are recommended for grazing-based sheep production systems.

Effects of by-product feed inclusion in a grass hay-based diet on nutrient disappearance, total gas and methane production, rumen fermentation and protozoal populations in an artificial rumen (RUSITEC)

2025-06-17

S. Robinson , Paul Tamayao , A.M. Saleem +5 more | Animal Production Science

Context Dietary manipulation can reduce enteric methane in beef cattle but limited options exist for perennial forage-based diets. Aims An artificial rumen system (RUSITEC) was used to assess the effects … Context Dietary manipulation can reduce enteric methane in beef cattle but limited options exist for perennial forage-based diets. Aims An artificial rumen system (RUSITEC) was used to assess the effects of including quinoa screenings, flax screenings, and sunflower screenings in a grass hay-based diet on nutrient disappearance, total gas production (GP), methane (CH4) production, ruminal fermentation, and protozoa populations. Methods The experiment was a randomized complete block design with four treatments assigned to 16 fermenters (n = 4 per treatment) in two RUSITEC apparatuses. The control diet was timothy grass hay only, with by-product treatments of grass hay plus quinoa screenings, flax screenings, or sunflower screenings, at inclusion rates of 21.4%, 11.2%, and 12.3% diet DM, respectively. The study duration was 15 days, with an 8-day adaptation period followed by a 7-day sample collection period. Data were analyzed using PROC MIXED in SAS with fixed effects of treatment, day of sampling (repeated measure), and their interaction and with RUSITEC and fermenter as random effects. Key results Compared to the control, the inclusion of quinoa and flax had no effect (P > 0.05) on dry matter (DMD) or organic matter disappearance; however, these were lower (P < 0.001) than sunflower. Sunflower and quinoa did not affect (P > 0.05) rumen fluid propionate production compared to the control; however, propionate production was increased (P < 0.05) with flax. Additionally, sunflower decreased (P = 0.044) rumen fluid acetate production as compared to the control, quinoa and flax groups. Sunflower, compared to the control, had fewer (P < 0.05) protozoa. There was no effect (P > 0.05) of by-products on GP (L day−1). Sunflower reduced (P < 0.05) CH4 by 42% (mg g−1) DM incubated and 31% (mg g−1) DMD, whereas quinoa and flax had similar CH4 production to the control. Conclusions This study suggested sunflower screenings have the potential to decrease CH4 when included in a grass hay-based diet. Implications Methane reduction was accompanied by reduced DMD, therefore, animal performance may be negatively impacted. Although quinoa and flax did not reduce CH4 production, they demonstrated potential to supplement hay-based diets without decreasing DMD.

Editorial: Crosslinking of feed nutrients, microbiome and production in ruminants

2025-06-17

Wenjuan Du , Wenjie Xu , Yin Hu +5 more | Frontiers in Veterinary Science

Effect of alfalfa hay quality in an alfalfa–maize diet on the digestion, metabolism, and growth rate of goats in the Longdong Loess Plateau

2025-06-16

Yuhong Jiang , Jieyan Zhou , Xianjiang Chen +3 more | Grassland Research

Abstract Background To optimize animal production systems for future sustainability, research now focuses on improving feed quality to enhance livestock performance. Here, we test the impact on goat metabolism of … Abstract Background To optimize animal production systems for future sustainability, research now focuses on improving feed quality to enhance livestock performance. Here, we test the impact on goat metabolism of varying leaf proportions in the alfalfa component of an alfalfa–maize diet. Methods In a pen‐feeding experiment, 16 three‐month‐old goats were divided into eight groups, four of which were fed a ration containing 40% alfalfa with leaves intact (LI) and four of which were fed an otherwise identical diet containing stemmy alfalfa (leaves removed, LR). Results As expected, LR reduced protein intake compared to LI (48.3 vs. 93.3 g d −1 ; p < 0.001) and increased acid detergent fiber intake (239 vs. 167 g d −1 ; p < 0.001), but neutral detergent fiber and dry matter digestibility did not differ between LR and LI. The LR group had lower gross energy, digestible energy, and metabolizable energy intakes than the LI group ( p = 0.080, 0.030, and 0.022, respectively). Retained nitrogen for LI and LR was 2.30 and 1.72 g d −1 , respectively. Body weight gain was 74 g d −1 in LI and 52 g d −1 in LR ( p < 0.001). Conclusions These results highlight that even where alfalfa is only one component of a mixed diet, the nutritive quality and leaf content of the alfalfa component are important to animal performance.

Microbial diurnal rhythmicity in the rumen fluid impacted by feeding regimes and exogenous microbiome providing novel mechanisms regulating dynamics of the rumen microbiome

2025-06-16

Yangyi Hao , Wei Wang , Mengmeng Li +7 more | Microbiome

Abstract Background Diurnal oscillations have been reported on ruminal prokaryotes, but the daily rhythmicity of eukaryotes remains unknown. This study investigated diurnal oscillations of ruminal prokaryotes and eukaryotes under three … Abstract Background Diurnal oscillations have been reported on ruminal prokaryotes, but the daily rhythmicity of eukaryotes remains unknown. This study investigated diurnal oscillations of ruminal prokaryotes and eukaryotes under three different feeding managements and rumen fluid transplantation conditions, aiming to elucidate the regulatory mechanisms influencing the dynamic shifts of rumen microbiome through the daily feeding cycle. Results Quantification and profiling of the microbiota of 288 rumen samples collected from lactating dairy cows ( n = 12) every 6-h over 48-h feeding cycles under ad libitum, restricted feeding at daytime and nighttime, respectively, revealed the rhythmicity in the population and abundance of ruminal bacteria, archaea, and protozoa. Under restricted-feeding regimes, 61.99% bacterial genera including Prevotella and Ruminococcus , and 7.19% archaeal species including Methanosphaera sp. ISO 3 -F 5, and 66.93% protozoa genera including Entodinium and Isotricha showed feeding-time-influenced changes in circadian rhythms. However, 4.76% bacterial genera such as Prevotellaceae_UCG- 001, and 0.29% archaeal species such as group 12 sp. ISO4-H5 exhibited non-feeding-time affected circadian rhythm pattern shifts. Further analysis of 176 rumen fluid samples collected after rumen fluid transplantation showed the proportion of bacterial, archaeal, and protozoal taxa displayed consistent (including Anaeroplasma and Fibrobacter ), inconsistent (including Bacteroidales_UCG- 001 and NK 4 A 214 _group ), gain (including Prevotella and Succinivibrio ), and loss (including Butyrivibrio and Mycoplasma ) of circadian rhythms over the 48-h to 7-day period after transplantation. Similar circadian patterns were found among feed intake, ruminal volatile fatty acid concentrations, bacterial functions such as glycolysis/gluconeogenesis, and deterministic assembly processes of bacterial communities. However, different circadian patterns (12-h shifts) were observed for rumination time, ruminal pH, ammonia nitrogen concentration, and bacterial functions such as chemotaxis, nitrogen metabolism, and deterministic assembly processes of archaeal communities. Additionally, cross-lagged effects were observed between the relative abundance of microbial taxa and rumen fermentation parameters, which could affect feed intake, rumination time, microbial population/diversity, and microbial interactions. Conclusions The classified feeding-time responsive, multi-factor responsive, consistent, and inconsistent circadian rhythm of microbial taxa underscore the driven factors behind the daily dynamics of rumen microbes, which also filled the gaps for targeting specific microbial taxa for better animal production.

Multi-Omics Revealed the Effects of Different Feeding Systems on Rumen Microorganisms, Cellulose Degradation, and Metabolites in Mongolian Cattle

2025-06-16

Kexin Jiang , Jianfei Ma , Junzhao Xu +2 more | Animals

Rumen microbiota is crucial for cellulose degradation and nutrient metabolism in ruminants. Different feeding systems like grazing and housed feeding can significantly impact it. Mongolian cattle show unique cellulose degradation … Rumen microbiota is crucial for cellulose degradation and nutrient metabolism in ruminants. Different feeding systems like grazing and housed feeding can significantly impact it. Mongolian cattle show unique cellulose degradation ability, but functional changes under different feeding conditions are unclear. This study aims to investigate the effects of grazing and housed feeding on rumen microbiota, cellulose degradation, and metabolism in Mongolian cattle. In a 90-day trial, 12 female Mongolian cattle were divided into grazing (F group) and housed feeding (S group). Rumen samples were collected to analyze fermentation parameters, enzyme activities, microbiomes, and metabolomes. The F group had higher acetate, cellulase, xylanase, and β-glucosidase activities (p < 0.05). Bacteroidota and Prevotella were more abundant (p < 0.05), while Firmicutes and Ruminococcus were less abundant (p < 0.05) in the F group. Carbohydrate metabolic pathways and CAZymes (GH2, GH10) were upregulated in the F group, while the S group had enriched purine metabolic pathways and CAZyme (GH31). A total of 64 differential metabolites were found, with subaphylline upregulated in the F group and L-arogenate in the S group (p < 0.05). Grazing increased cellulose degradation and subaphylline production in Mongolian cattle, while housed feeding improved starch utilization efficiency and fat synthesis. These findings provide a basis for optimizing feeding strategies and improving fibrous feed resource utilization in Mongolian cattle.

Forecasting the performance of alternative sheep production systems grazing perennial pastures

2025-06-16

Christine Storer , Sosheel Godfrey , Susan Robertson +2 more | Agricultural Systems

Exploring the Sustainable Utilization of Alfalfa Within the Phytomedicine Domain

2025-06-15

Sen Shi , Yun Guo , Hui Zhi | Plant Cell & Environment

ABSTRACT Wild alfalfa is a ubiquitous legume crop and an important feed for livestock such as cattle and sheep. However, despite its agricultural significance, the potential of alfalfa as a … ABSTRACT Wild alfalfa is a ubiquitous legume crop and an important feed for livestock such as cattle and sheep. However, despite its agricultural significance, the potential of alfalfa as a medicinal raw material remains largely untapped, with particularly limited research focusing on the bioactivity of its phenolic compounds. This study aimed to systematically evaluate the phenolic profiles, antioxidant capacities, and antimicrobial effects of three common wild alfalfa species to explore their potential as sustainable sources of phytomedicinal ingredients. A comprehensive analysis was conducted on the growth characteristics, photosynthetic parameters and metabolic profiles of Medicago sativa ( M. sativa ) L., Medicago falcata ( M. falcata ) L. and Medicago ruthenica ( M . ruthenica ) L. collected from Hulunbuir Prairie, China. Phenolic compounds were quantified using HPLC–MS, while antioxidant activities were assessed via FRAP and ABTS assays. Antimicrobial efficacy was tested against gram‐positive ( Staphylococcus aureus [ S. aureus ], Bacillus subtilis ) and gram‐negative ( Escherichia coli , Acinetobacter baumannii ) bacteria using agar diffusion and microdilution techniques. M. falcata L. demonstrated the greatest plant height (81 cm) and basal stem diameter (5.7 mm), while M. sativa L. exhibited the highest photosynthetic rate (9.3 μmol m −2 s −1 ) and chlorophyll content, indicating distinct species‐specific adaptations. Phytochemical analysis showed that the leaves were rich in phenolic compounds including isoliquiritigenin and ferulic acid, while roots contained substantial l ‐phenylalanine and trigonelline. Leaf and root extracts of three wild alfalfa species exhibited notable antioxidant capacity, with M. ruthenica leaves showing the highest activity (FRAP: 149.2 ± 2.7 mmol Fe (II)/g DW; ABTS: 100.5 ± 2.8 mmol TE/g DW), highlighting their potential as natural antioxidant sources. The extracts exhibited selective antibacterial efficacy against gram‐positive pathogens ( S. aureus , etc.), demonstrating inhibition zones of 15.2–18.2 mm and MIC values of 313 mg/mL. Phenolic compounds in alfalfa possess biological activities such as antioxidant and antibacterial properties. Many phenolic compounds are difficult and expensive to synthesize, leading to supply shortages. Alfalfa, as a common and widely distributed crop, can provide a plant source for antioxidants and antimicrobials. This study provides new guidance to meet the demand for phytomedicinal ingredients. It offers data to support the development of medicines for human health.

Evaluation of high-moisture oat silage inoculated with synthetic lactic acid bacteria consortia in mini-silos: fermentation, microbial, metabolic and safety profiles

2025-06-15

Cheng Zong , Longxin Wang , Jie Zhao +5 more | Italian Journal of Animal Science

Long read 16S amplicon analyses and improved cultivation techniques as joined approach for the identification of viable bacterial populations in silage

2025-06-14

Wanda Flegler , F. Behrens , Anne Theresa Sturmhöfel +7 more | Journal of Applied Microbiology

Abstract Aims Lactic acid bacteria (LAB) are crucial for the quality and preservation of silage. Exploration and isolation of the key microbiome are important for improving fermentation processes. While cultivation-dependent … Abstract Aims Lactic acid bacteria (LAB) are crucial for the quality and preservation of silage. Exploration and isolation of the key microbiome are important for improving fermentation processes. While cultivation-dependent methods enable the isolation of LAB, they often overlook organisms with challenging cultivation requirements. Next-generation sequencing provides cultivation-independent microbiome insights. In contrast to commonly used methods, long-read sequencing platforms like the Pacific Biosciences (PacBio) single-molecule real-time (SMRT) platform offer species-level resolution. This study aims to investigate the benefits of a combined cultivation-dependent and –independent approach for silage microbiome analyses. Methods and Results The common isolation medium for LAB was supplemented with sterile pressed juice from plant material improving the cultivation conditions. PacBio amplicon sequencing provided an almost complete and cultivation-independent picture of the bacterial community. The use of mock communities and a live/dead discriminating treatment of the samples revealed that the analysis can be misleading if appropriate controls are not performed. Conclusion Growth of plant-associated microorganisms can be supported by a plant juice containing isolation medium, allowing isolation of the dominant LAB from silage. Microbial dynamics can be represented using long-read sequencing. However, the use of controls such as a live/dead discrimination and mock communities is essential for the reliability of the data.

Effects of Dietary Protein Levels on Production Performance, Meat Quality Traits, and Gut Microbiome of Fatting Dezhou Donkeys

2025-06-14

Yunpeng Wang , Keqiang Diao , Li Han +3 more | Microorganisms

This study aimed to investigate the effects of varying dietary protein levels on growth performance, meat quality traits, amino acid and fatty acid compositions, and hindgut microbiota in Dezhou donkeys. … This study aimed to investigate the effects of varying dietary protein levels on growth performance, meat quality traits, amino acid and fatty acid compositions, and hindgut microbiota in Dezhou donkeys. Eighteen 12-month-old male donkeys, weighing 188 ± 9 kg, were randomly allocated into three groups and fed diets containing 11.03% (LP), 12.52% (MP), and 14.06% (HP) protein. The average daily gain (ADG) was significantly higher (p < 0.05) in the HP and MP groups, while the feed conversion ratio (FCR) was lower (p < 0.05) compared to the LP group. The MP group exhibited superior performance in terms of serum albumin (ALB) and high-density lipoprotein (HDL) levels, as well as protein digestibility (p < 0.05). Improvements in meat tenderness, as well as increased levels of leucine, flavor amino acids (FAAs), and non-essential amino acids (NEAAs) (p < 0.05), were observed in the MP group compared to those in the LP and HP groups. The levels of total fatty acids (TFAs), saturated fatty acids (SFAs), unsaturated fatty acids (UFAs), and monounsaturated fatty acids (MUFAs) were higher (p < 0.05) in the LP and MP groups than in the HP group, with no significant differences (p > 0.05) observed between the LP and MP groups. The genera Prevotella, Clostridium_sensu_stricto_1, NK4A214_group, Oscillospiraceae_UCG-002, and Oscillospiraceae_UCG-005 in the rectum were identified as differential microbes associated with varying dietary protein levels. In conclusion, this study indicates that a dietary protein level of 12.52% could enhance the growth performance, dietary nutrient digestibility, slaughter performance, and meat quality of Dezhou donkeys by modulating hindgut microbial communities.

Characterisation of the Faecal Microbiome of Alpacas Raised in South Eastern Australia

2025-06-13

Imogen Boughey , Francisca Samsing , E Hall +2 more | Animals

There is limited investigation of the alpaca microbiome on a global scale, with no previous research conducted in Australia characterising the faecal microbiome. The microbiome composition in other ruminants has … There is limited investigation of the alpaca microbiome on a global scale, with no previous research conducted in Australia characterising the faecal microbiome. The microbiome composition in other ruminants has been shown to impact feed efficiency, average daily gain and methane production. This study aimed to characterise the faecal microbiome of alpacas raised in south-eastern Australia and identify variation across geographic regions. Faecal samples were collected from 59 healthy adult female alpacas, aged between 15 months and 17 years in NSW, Australia. Firmicutes were identified as the dominant phyla, accounting for 57.78% of the cumulative abundance, followed by Bacteroidota (29.12%). These two phyla accounted for 90% of the taxa, with the cumulative abundance of Firmicutes and Bacteriodota significantly differing (p < 0.05) across locations. There was no effect of age on the frequency of microbes identified at either phyla or class levels. The alpaca’s production status only significantly affected the abundance of Firmicutes Clostridia Oscillospirales (p = 0.0026). The breakdown of the alpaca faecal microbiome identified here is consistent with previous ruminant and camelid studies. This study provides a valuable baseline for the microbiome characterisation of alpacas in south-eastern Australia and can be used as a baseline for further microbiome studies.

Assessment of rice bran with acrylate or pyruvate in modulating ruminal fermentation and methane production in vitro

2025-06-13

Jamal James D. Manlapig , Jane Camille A. Crisostomo , Makoto Kondo +2 more | Journal of the Science of Food and Agriculture

Abstract BACKGROUND Livestock production contributes largely to climate change and methane (CH 4 ) from enteric fermentation is the primary greenhouse gas emitted from ruminants. Thus, developing effective strategies to … Abstract BACKGROUND Livestock production contributes largely to climate change and methane (CH 4 ) from enteric fermentation is the primary greenhouse gas emitted from ruminants. Thus, developing effective strategies to reduce the impact of ruminant production on the environment is crucial, and the combination of CH 4 mitigating agents may be a viable strategy to attain this. The present study aimed to evaluate the effect of rice bran alone (control+rice bran, RB) or in combination with acrylate (control+rice bran+acrylate, AA) or pyruvate (control+rice bran+pyruvate, PA) on rumen fermentation parameters, CH 4 production, and microbial populations in vitro. RESULTS Gas production was highest in control + rice bran + pyruvate (PA) treatments and lowest ( P < 0.01) in control + rice bran + acrylate (AA), whereas dry matter digestibility (DMD) was significantly lower ( P < 0.05) in AA compared to control (CON) and PA. CH 4 and CH 4 /digested dry matter decreased ( P < 0.05) by more than 66% and 63%, respectively, in AA cultures, whereas total organic acid production increased ( P < 0.01) compared to CON. Lactate levels were significantly higher ( P < 0.05), while acetate, propionate and butyrate were notably lower ( P < 0.05) in AA cultures than CON. Microbial analysis showed a significant decrease in methanogen populations in AA than CON ( P < 0.01). Compared to CON, anaerobic fungi and Megasphaera elsdenii populations declined across all treatments ( P < 0.01), whereas Selenomonas ruminantium populations decreased in RB and AA, and Prevotella ruminicola populations were higher in RB and PA ( P < 0.05). CONCLUSION These findings suggest that incorporating RB with AA could be a viable CH 4 inhibitor; however, because of its negative effect on gas production and DMD, further investigations should be done to determine its optimum inclusion level. © 2025 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Salvianolic Acid C Inhibits Methane Emissions in Dairy Cows by Targeting MCR and Reshaping the Rumen Microbial Community

2025-06-13

Zihao Liu , Xiao Li , Xiangfang Tang +5 more | Research Square (Research Square)

<title>Abstract</title> Background Methane (CH₄) emissions from ruminants significantly contribute to greenhouse gas effects and energy loss in livestock production. Methyl-coenzyme M reductase (MCR) is the key enzyme in methanogenesis, making … <title>Abstract</title> Background Methane (CH₄) emissions from ruminants significantly contribute to greenhouse gas effects and energy loss in livestock production. Methyl-coenzyme M reductase (MCR) is the key enzyme in methanogenesis, making it a promising target for CH₄ mitigation. This study aimed to identify and validate plant-derived inhibitors by employing molecular docking to screen compounds with strong binding affinity to the F430 active site of MCR and assessing their efficacy in reducing CH₄ emissions. Results Molecular docking analysis identified Salvianolic acid C (SAC) as a potent inhibitor of MCR, exhibiting a strong binding affinity to the F430 active site (binding energy: −8.2 kcal/mol). Enzymatic inhibition assays confirmed its inhibitory effect, with a half-maximal inhibitory concentration (IC₅₀) of 692.3 µM. In vitro rumen fermentation experiments demonstrated that SAC supplementation (1.5 mg/g DM) significantly reduced CH₄ production (<italic>P</italic> < 0.01) without negatively affecting key fermentation parameters. Microbial community analysis using 16S rRNA sequencing and metagenomics revealed that SAC selectively altered the rumen microbiota, increasing the relative abundance of <italic>Bacteroidota</italic> while significantly reducing <italic>Methanobrevibacter</italic> (<italic>P</italic> = 0.04). Additionally, metagenomic analysis indicated the downregulation of key methanogenesis-related genes (<italic>mcrA</italic>, <italic>rnfC</italic>), suggesting a dual mechanism involving direct enzymatic inhibition and microbial community modulation. Conclusions These findings indicate that SAC effectively reduces CH₄ production by inhibiting MCR activity and reshaping the rumen microbial community. As a plant-derived compound with strong inhibitory effects on methanogenesis, SAC presents a promising and sustainable alternative to synthetic methane inhibitors, offering potential applications in mitigating CH₄ emissions in livestock production.

Effect of breed and fattening system on fattening performance, rumen and blood parameters in Akkaraman, Karayaka and Herik lambs under indoor conditions

2025-06-13

Mustafa UĞURLU , Akif Uysal , Buket Nacar +6 more | Ankara Üniversitesi Veteriner Fakültesi Dergisi

This research was performed to determine comparative effect of concentrate and forage-based diets on fattening performance, rumen and blood serum parameters of Akkaraman, Karayaka and Herik lambs under intensive indoor … This research was performed to determine comparative effect of concentrate and forage-based diets on fattening performance, rumen and blood serum parameters of Akkaraman, Karayaka and Herik lambs under intensive indoor conditions. In this study forty-five single male lambs, aged 2.5-3 months, were randomly selected from the same flock of each breed. The lambs were divided into two different concentrate/forage ratios (70/30 and 30/70) for each breed. The lambs were fed with concentrated feed and dry alfalfa until they reached 40 kg slaughter weight. In both of diet groups, average daily weight gain (ADWG) and feed conversion rate (FCR) for Akkaraman lambs were better than those of Karayaka and Herik lambs. The rumen pH of the concentrate groups was significantly lower than that of the forage groups for all breeds (P < 0.001). Total volatile fatty acid (TVFA) for Herik lambs was higher than that of Akkaraman and Karayaka lambs in both of diet groups. TVFA and total ammonia nitrogen (NH3-N) concentrations of lambs in the concentrate groups were significantly higher than those of the lambs in the forage groups (P < 0.001). Consequently, the study indicates that fattening performance for Akkaraman lambs was better than that of Karayaka and Herik lambs in both of diet groups, as shown by higher ADWG and better FCR values. The diet was effective (P < 0.001) on all rumen parameters. Also, the present study confirms that blood parameters have normal levels.

The rumen microbiota and metabolism of dairy cows are affected by the dietary rate of inclusion of Yucca schidigera extract

2025-06-12

Timothy J. Snelling , Marykate Condren , James A. Huntington +3 more | Microbiology Spectrum

ABSTRACT Natural plant compounds can be used to supplement livestock diets, improving feed efficiency, production, and health, while also reducing environmental impact. In the present study, a Yucca schidigera (Mohave … ABSTRACT Natural plant compounds can be used to supplement livestock diets, improving feed efficiency, production, and health, while also reducing environmental impact. In the present study, a Yucca schidigera (Mohave Yucca) extract was added at four rates of inclusion (ROI) of 0, 5, 15, or 30 g/day to a ryegrass and maize silage-based diet and fed to dairy cows in a 4 × 4 Latin square experimental design. Each period was 28 days in duration, with sampling undertaken during the final week of each period. Solid phase digesta (SPD) and liquid phase digesta (LPD) samples were collected via a rumen cannula and analyzed for volatile fatty acids (VFAs), ammonia N, and microbiome using 16S rRNA gene sequencing. Total fecal and urine collection was undertaken over a 3-day period. Rumen microbial diversity was not affected by ROI (LPD: P = 0.180; SPD: P = 0.059). However, discriminant analysis found a decrease in Methanobrevibacter millerae (linear discriminant analysis, LDA = 2.15) and an increase in an unclassified species of Proteobacteria (LDA = 2.10) associated with ROI. Univariate analysis also revealed differential abundance of operational taxonomic units classified as Prevotellaceae and Fibrobacteraceae by ROI ( P < 0.05). Maximum rumen ammonia N concentration decreased linearly from 228 to 109 mg/L with ROI ( P = 0.044). Rumen VFA concentration was unaffected with the exception of propionate, which showed a linear increase with ROI ( P = 0.010). The diurnal rumen pH range (maximum–minimum) also decreased with ROI ( P = 0.004). Dry matter intake and milk yield were not affected ( P > 0.05) by ROI; however, there was a linear increase in milk fat content from 38.9 to 42.0 g/kg with ROI ( P < 0.05). IMPORTANCE Domestic livestock such as dairy cows are inefficient utilizers of dietary nitrogen. This increases feed costs and reduces animal production efficiency. Excreted nitrogenous compounds are also an environmental hazard, such as when they enter water courses as nitrate or are lost to the atmosphere as ammonia or nitrous oxide. Dietary protein is degraded in the rumen via the activity of the microbial population, mainly into ammonia, which may then be utilized by the microbial population to synthesize microbial protein or absorbed into the blood and potentially excreted. Manipulation of the diet or altering the microbial population may increase the utilization of dietary protein, increasing animal performance, decreasing feed costs, and reducing the environmental impact of milk production. This study examines the effect of Yucca schidigera extract on the rumen microbiome and nitrogen utilization in dairy cows.

Economic analysis of benefits from grazing unharvested standing lupin crops in a mixed farm enterprise in south-west Western Australia

2025-06-12

Amelia Gooding , Serina Hancock , A. N. Thompson +1 more | Animal Production Science

Context In the south-west of Western Australia, weaned lambs typically graze dry annual pastures and crop stubbles during late spring, summer and autumn (October–March). The low energy and protein content … Context In the south-west of Western Australia, weaned lambs typically graze dry annual pastures and crop stubbles during late spring, summer and autumn (October–March). The low energy and protein content of these feeds typically means that lambs are supplemented with concentrates to achieve target growth rates. Fully mature, standing lupin crops that could be harvested may provide higher quality feed than dry pasture and crop stubbles over this period. Aims This study tested the hypothesis that the incorporation of standing lupin crops for grazing will increase whole-farm profitability. Furthermore, we aimed to quantify the relative contributions of stocking rate, sale value of lambs, weaner survival rate and ewe lamb reproduction to this increase in farm profit. Methods Whole-farm bioeconomic modelling was used to assess the profitability of grazing standing lupin crops in a mixed farming system. An analysis was conducted for a representative mixed farm in south-west Western Australia with a self-replacing Merino flock, and the profitability of grazing a lupin crop was assessed on the basis of whether it was harvested or grazed. A sensitivity analysis was then carried out to test the robustness of the results and understand the role of standing lupin crops in a mixed farming system. Key results Grazing lupins grown on 7% of the total farm area increased whole-farm profitability by almost A$30,000 or A$200/ha of standing crop. In this environment, across a range of assumed crop yields and prices, it was always more profitable to graze standing lupins rather than harvest the lupins. The increase in profit was primarily due to an increase in stocking rate of 1.2 dry sheep equivalent per hectare when able to graze the optimum area of standing lupins compared to when there was no standing crop. In addition to the increase in stocking rate, revenue from sheep sales increased, with the Merino wether and mixed sex crossbred weaners sold for an extra A$13 per lamb when stocking rate was constrained to the optimum for when there was no standing lupin crop. Conclusions This analysis demonstrated that in the south-west of Western Australia, grazing standing lupin crops was always more profitable than harvesting the grain. Implications If lupins are included in crop rotations in this environment, profit will be increased if they are grazed, but it is also clear that stocking rate should be increased to fully capitalise on potential gains in farm profit.