Rumen Of Animals Research Articles

PSXII-21 How does the inclusion of dried distillers grains plus soluble affect short-chain fatty acid and methane production in feedlot diets?

Abstract The inclusion of the coproduct dry distillers grains plus soluble (DDGS) in the diet of finishing cattle can lead to changes in the nutritional profile of the diets, causing an increase in protein content and a reduction in starch. It is necessary to understand how changes in rumen substrates affect rumen metabolic activity, acids, and enteric methane (CH4) production. Five treatments were used, considering levels of DDGS inclusion in the dry matter (DM) of 1) 0 g/kg of DDGS, 2) 150 g/kg of DDGS, 3) 300 g/kg of DDGS, 4) 450 g/kg DDGS, or 5) 600 g/kg DDGS in finishing diets. The metabolism experiment was conducted with rumen-cannulated Nellore bulls (n = 20) with initial body weight (BW) of 401.8 ± 27.0 kg. The production of short-chain fatty acids (SCFA) and CH4 were determined using the ex-situ ruminal fermentation technique. Rumen content was manually collected from 0, 4, 8 and 12 h post-feeding. The liquid and solid fractions of rumen content were used in four 50 mL penicillin-type flasks per animal. Of the four flasks prepared, two are called “blank” and inactivated in boiling water to stop fermentation, and the other two (microrumen) are incubated in a thermostatic bath, simulating the conditions existing in the rumen of animals (presence of microorganisms, anaerobes, temperature of 39ºC, natural animal saliva, physiological pH) for 30 min. After 30 min, incubated flasks were also inactivated in boiling water to stop fermentation. Subsequently, measurements of the final products of rumen fermentation (SCFA and CH4) were carried out in each bottle. Total rumen emptying was performed to determine the rumen pool of DM. The data will be analyzed in the SAS software, the mean of the treatments will be compared using test of mean and orthogonal contrasts. The declared significance is P ≤ 0.05. The inclusion or levels of DDGS did not affect CH4 production of gּ kg DM-1ּ d-1 and gּ kg DM-1ּ d-1 (P > 0.05). There was an effect of the treatments on the production of propionate (gּ kg DM-1ּ d-1; P = 0.0448), with a decreasing linear effect (P = 0.0087) with the increase in the inclusion of DDGS in diet (0; 150; 300; 450; 600 g/kg of DDGS; means 137.20; 160.32; 117.60; 87.09; 91.52 gּ kg DM-1ּ d-1 propionate, respectively). There was no effect of DDGS levels on the production of Acetate, Butyrate, or total SCFAs (gּ kg DM-1ּ d-1). In summary, DDGS inclusion affects rumen metabolic activity, decreasing propionate production, but does not affect the production of other SCFAs nor CH4 production.

β-Dicarbonyls Facilitate Engineered Microbial Bromoform Biosynthesis.

Ruminant livestock produce around 24% of global anthropogenic methane emissions. Methanogenesis in the animal rumen is significantly inhibited by bromoform, which is abundant in seaweeds of the genus Asparagopsis. This has prompted the development of livestock feed additives based on Asparagopsis to mitigate methane emissions, although this approach alone is unlikely to satisfy global demand. Here we engineer a non-native biosynthesis pathway to produce bromoform in vivo with yeast as an alternative biological source that may enable sustainable, scalable production of bromoform by fermentation. β-dicarbonyl compounds with low pKa values were identified as essential substrates for bromoform production and enabled bromoform synthesis in engineered Saccharomyces cerevisiae expressing a vanadate-dependent haloperoxidase gene. In addition to providing a potential route to the sustainable biological production of bromoform at scale, this work advances the development of novel microbial biosynthetic pathways for halogenation.

Lachnospiraceae are emerging industrial biocatalysts and biotherapeutics.

The Lachnospiraceae is a family of anaerobic bacteria in the class Clostridia with potential to advance the bio-economy and intestinal therapeutics. Some species of Lachnospiraceae metabolize abundant, low-cost feedstocks such as lignocellulose and carbon dioxide into value-added chemicals. Others are among the dominant species of the human colon and animal rumen, where they ferment dietary fiber to promote healthy gut and immune function. Here, we summarize recent studies of the physiology, cultivation, and genetics of Lachnospiraceae, highlighting their wide substrate utilization and metabolic products with industrial applications. We examine studies of these bacteria as Live Biotherapeutic Products (LBPs), focusing on in vivo disease models and clinical studies using them to treat infection, inflammation, metabolic syndrome, and cancer. We discuss key research areas including elucidation of intra-specific diversity and genetic modification of candidate strains that will facilitate the exploitation of Lachnospiraceae in industry and medicine.

Policy and Regulatory Frameworks Addressing Methane Emissions in Dairy Farming

Currently, there are more than 1 billion cows in the world that produce more than 1.5 billion tons of milk annually. According to the increasing demand for milk consumption in the world, it is predicted that by 2028, the number of these cows will reach more than 1.5 billion. In addition to increasing global warming, animal husbandry plays a significant role in the production of greenhouse gases, including methane*. Because each dairy cow can produce an average of 400 liters of methane per day. On the other hand, the production of methane in the rumen of animals causes an average loss of 6% of energy in animals**. Therefore, in recent years, strategies and techniques to reduce methane emissions in animal husbandry have attracted the attention of governments, researchers, animal husbandry and environmentally conscious consumers.

Effect of different doses of cobalt on rumen digestion in cattle

Optimization of mineral nutrition is a necessary measure to maintain high productivity of beef cattle which often lack minerals in their feed. The innovative base in this case can be ultrafine particles of essential elements characterized by high bioavailability in a small dose. The effect of ultrafine Co3O4 particles on the digestibility of dry matter of feed in the in vitro system (artificial rumen), the amount of volatile fatty acids, nitrogen forms (total, non-protein, ammonia, urea, protein) and on the amino acid composition (arginine, lysine, methionine, alanine, glycine) of animal rumen fluid was studied. The research was conducted in 2023. Cattle of the Kazakh white-headed breed aged 11-12 months with an average weight of 265-275 kg were used as an object of research. It was found that in in vitro studies, dry matter digestibility of feed was 9.0% higher at a concentration of 0.36 g/mL of Co3O4 ultrafine particles. Analysis of volatile fatty acid concentration showed that this dosage increases acetic acid, propionic acid, butyric acid, valerianic acid, and caproic acid. The introduction of ultrafine Co3O4 particles increased the content of protein nitrogen and total nitrogen in the experimental animals, indicating the intensification of rumen microbiocenosis. At introduction of ultrafine Co3O4 particles, shifts in the amino acid composition of the rumen contents were observed, which may be caused by the changes in the nature of nitrogenous substances transformation in the digestive tract. It is concluded that the use of ultrafine Co3O4 particles has a positive effect on the digestive processes in the rumen.

Effects of Post-Ruminal Urea Supplementation during the Seasonal Period on Performance and Rumen Microbiome of Rearing Grazing Nellore Cattle.

The objective was to evaluate the effects of urea with post-ruminal absorption in the supplementation of growing Nellore cattle reared on pasture during a seasonal period. For the study, two experiments were conducted. In experiment 1, rumen and blood parameters were evaluated using eight rumen-cannulated Nellore bulls with initial body weight (BW) of 763 ± 44 kg, distributed in a double Latin square 4 × 4. In experiment 2, 120 Nellore steers with initial BW of 380 ± 35 kg were used for performance evaluation, distributed in a randomized block design (blocking factor or initial BW). The evaluated treatments were 1: (TP-U) (control) = supplement with 24% crude protein (CP) containing urea as a source of non-protein nitrogen (NPN; 3%) and soybean meal, 2: (TP-PRU) = 24% CP supplement containing post-ruminal urea (PRU; 3.6%) and soybean meal; 3: (NPN-U-PRU) = 24% CP supplement containing urea + post-ruminal urea (U = 3% and PRU = 3.9%), without soybean meal; 4: (NPN-PRU) = supplement with 24% CP containing post-ruminal urea (7.5%), without soybean meal. The supplement was offered at 3 g/kg BW per animal, daily, once a day. All animals were kept on Urochloa brizantha cv. Marandu pasture. Statistical analyses were performed using the SAS PROC MIXED, and the data were evaluated by the following contrasts: C1 = TP-U/TP-PRU vs. NPN-U-PRU/NPN-PRU (Soybean meal replacement by NPN); C2 = TP-U vs. TP-PRU (conventional urea vs. post-immune urea); C3 = NPN-U-PRU vs. NPN-PRU (low and high post-ruminal urea-PRU level). The digestibility of dry matter, organic matter, and NDF was lower when soybean meal was replaced by non-protein nitrogen, also being different between the levels of post-ruminal urea used in the supplement. Ruminal pH was different when soybean meal was replaced by NPN (p = 0.003). Total concentration of short-chain fatty acids, concentrations of isobutyrate (p = 0.003), valerate (p = 0.001), and isovalerate (p = 0.001) were different, and blood urea was different when soybean meal was replaced by NPN (p = 0.006). Simpson's diversity index was higher in the rumen of animals supplemented with TP-U than in those supplemented with TP-PRU (p = 0.05). A total of 27 phyla, 234 families, and 488 genera were identified. Nitrospirota and Gemmatimonadota phyla were detected just in the rumen of steers supplemented with TP-PRU. The performance (final BW, weight gain and gain per area) of the animals was different, being higher (p = 0.04) in animals supplemented with soybean meal, compared to NPN. The removal of soybean meal from the supplement and its replacement with either conventional urea plus post-ruminal urea or only post-ruminal urea compromises the performance of the animals. The lower the post-ruminal urea inclusion level, the lower the apparent digestibility of dry matter, organic matter, and NDF, when compared to animals supplemented with higher levels.

Балансирование рационов молодняка крупного рогатого скота по протеину за счёт небелковых азотистых веществ

Aim. The study of the effect of the inclusion of non-protein nitrogenous substances in the diet of young bulls on the breakdown of protein in the rumen and the digestibility of nutrients in diets. Materials and Methods. In the course of the study, zootechnical, biochemical and mathematical methods of analysis were used. The obtained digital material was processed by the method of variation statistics, taking into account the Student's t-test, using the Microsoft Excel software package. Results. As a result of studying the effectiveness of using of carbamide concentrate in the amount of 10, 15, 20 and 25% as part of compound feed in the feeding of young cattle, it was found that the degree of cleavage of feed protein with the addition of carbamide concentrate in the amount of 10-30% of the feed weight was 56-63% after 4 hours of incubation, 70-75% after 6 hours and 79-84% after 24 hours. As the results of the experiment showed, in the rumen of the animals of the experimental groups, a pH shift to the neutral side by 4.1-7.8% was noted, and when 25 and 30% of the studied feed were included in the diet, the difference turned out to be significant. There was also an increase in the amount of protein nitrogen and infusoria in the rumen of young animals that consumed 10, 20 and 25% of urea concentrate as part of compound feed. In the cicatricial fluid of bulls consuming compound feed with the inclusion of urea concentrate, the protein cleavage was higher than in the control group animals consuming compound feed without urea concentrate. The digestibility of nutrients in groups of animals with 10 and 20% introduction of carbamide concentrate into the compound feed increased by 1.08-11.22 percentage points. Conclusion. The degree of cleavage of the feed protein with the addition of carbamide concentrate in an amount of 10-30% of the feed weight was 56-63% after 4 hours of incubation, 70-75% after 6 hours and 79-84% after 24 hours. The digestibility of dry matter in groups of animals with 10 and 20% introduction of urea concentrate into compound feed increased by 2.89 and 1.71 pp., fat – by 11.22 and 2.28, protein – by 10.0 and 8.23, organic matter – by 2.14 and 0.81, Nitrogen-free extractive fraction – by 4.81 and 1.08 pp., in relation to control. It also turned out to be higher than in the groups with 25 and 30% introduction of urea concentrate into feed.

PSVII-10 Effects of Supplementing a Standardized Plant-Derived Feed Additive Containing Isoquinoline Alkaloids on Rumen Lesions in Feedlot Cattle

Abstract Long-term feeding of high grain diets can lead to digestive disorders which can result in inflammation of the digestive tract, poor performance and a negative impact on animal welfare. Plant-derived feed additives are widely used in food producing animals to improve the productivity, digestibility, and health. The objective of the present study was to assess the effects of supplementing a plant-derived feed additive containing standardized concentrations of isoquinoline alkaloids (IQ) on rumen lesions in finishing feedlot cattle. Crossbreed bulls from a commercial feedlot were enrolled in the present study. During the control period (CON; n = 470): from September 1st to October 12th cattle were fed the feedlot finishing diet. During the treatment period (TRT; n = 480): from October 13th to November 23rd finishing feedlot cattle were fed the same ration plus 600 g/t of a feed additive with standardized concentrations of IQ. Slaughter was performed in 2 abattoirs and the rumen of animals were examined by the same investigator. Rumen health was scored by visual observation of the rumen epithelia: 1) normal rumen; 2) mild rumenitis; 3) moderate rumenitis; 4) diffuse rumenitis 5) ulcerative rumenitis. Statistical analysis was performed with the R software. The Pearson chi-squared statistic was performed to test the independence between the variables. Results showed that TRT had greater and positive association with score 2 (P< 0.05; 3.2), and a negative association (P< 0.05) with scores 4 (-1.1) and 5 (-1.1). The CON presented greater and positive association with score 3 (P< 0.05; 3.3), as well as positive association (P< 0.05) for the scores 4 (1.1) and 5 (1.1). In conclusion, supplementing finishing feedlot cattle with a plant-derived feed additive containing IQ resulted in less severe rumen lesions in feedlot cattle receiving finishing diets indicating that IQ exerted a positive effect on rumen condition.

Differences in the Composition of the Rumen Microbiota of Finishing Beef Cattle Divergently Ranked for Residual Methane Emissions.

With the advent of high throughput technology, it is now feasible to study the complex relationship of the rumen microbiota with methanogenesis in large populations of ruminant livestock divergently ranked for enteric emissions. Recently, the residual methane emissions (RME) concept has been identified as the optimal phenotype for assessing the methanogenic potential of ruminant livestock due to the trait’s independence from animal productivity but strong correlation with daily methane emissions. However, there is currently a dearth of data available on the bacterial and archaeal microbial communities residing in the rumens of animals divergently ranked for RME. Therefore, the objective of this study was to investigate the relationship between the rumen microbiota and RME in a population of finishing beef cattle. Methane emissions were estimated from individual animals using the GreenFeed Emissions Monitoring system for 21 days over a mean feed intake measurement period of 91 days. Residual methane emissions were calculated for 282 crossbred finishing beef cattle, following which a ∼30% difference in all expressions of methane emissions was observed between high and low RME ranked animals. Rumen fluid samples were successfully obtained from 268 animals during the final week of the methane measurement period using a trans-oesophageal sampling device. Rumen microbial DNA was extracted and subjected to 16S rRNA amplicon sequencing. Animals ranked as low RME had the highest relative abundances (P < 0.05) of lactic-acid-producing bacteria (Intestinibaculum, Sharpea, and Olsenella) and Selenomonas, and the lowest (P < 0.05) proportions of Pseudobutyrivibrio, Butyrivibrio, and Mogibacterium. Within the rumen methanogen community, an increased abundance (P < 0.05) of the genus Methanosphaera and Methanobrevibacter RO clade was observed in low RME animals. The relative abundances of both Intestinibaculum and Olsenella were negatively correlated (P < 0.05) with RME and positively correlated with ruminal propionate. A similar relationship was observed for the abundance of Methanosphaera and the Methanobrevibacter RO clade. Findings from this study highlight the ruminal abundance of bacterial genera associated with the synthesis of propionate via the acrylate pathway, as well as the methanogens Methanosphaera and members of the Methanobrevibacter RO clade as potential microbial biomarkers of the methanogenic potential of beef cattle.

Citrus Pulp Replacing Corn in the Supplement Decreased Fibre Digestibility with No Impacts on Performance of Cattle Grazing Marandu Palisade Grass in the Wet-Dry Transition Period.

Simple SummaryDeterioration of forage quality as the dry season approaches has detrimental effects on the performance of cattle grazing tropical grasses unless supplementation strategies are implemented. In this study, corn was replaced by citrus pulp as an energy source to evaluate the effects of supplementation on liveweight performance and metabolic parameters of Bos indicus cattle grazing Urochloa brizantha cv. Marandu in the wet-dry transition period.The wet-dry transition period brings unique challenges to cattle producers in the tropics as the forage quality starts to decrease and animal performance is negatively affected unless supplementation strategies are applied. Two experiments were conducted concomitantly to evaluate the performance and metabolic parameters of cattle supplemented with two different energy sources under a C4 tropical grass continuous grazing system in the wet-dry transition period. In experiment (exp) 1, the liveweight (LW) gain of 42 growing Bos indicus Nellore bulls allocated to 12 paddocks of Uruchloa brizantha cv. Marandu, in a completely randomized block design, was evaluated to compare corn and citrus pulp-based supplements offered at 0.5% LW. Metabolism was evaluated in exp 2 with eight rumen-cannulated Nellore steers in an incomplete replicated Latin square design (RLSD) 4 × 2 (steers × treatment) fed the same two treatments as in exp 1. No differences in animal performance were observed between corn or citrus pulp-based supplements. Rumen pH, ammonia nitrogen, and blood urea nitrogen were lower in the rumen of animals supplemented with citrus pulp. Despite this, there were no differences in total dry matter intake amongst the two energy sources. The neutral detergent fibre digestibility of the diet containing corn decreased, but it neither affected performance nor liveweight gain per area. The findings suggest that corn can be replaced by citrus pulp with neither detrimental effects on animal performance nor indirect effects on pastures productivity.

Composition and functions of rumen and endometrial microorganisms associated with endometritis in dairy cows

Despite the attention given in the recent years to the microbiological causes of endometritis and the potential sources of uterine microbiota infestation, more questions than answers remain in this research field. This paper describes an experiment carried out at the livestock farm of the Leningrad region on 6 dairy cows of the Holsteinized Russian Black Pied breed of the second lactation in the period after calving. The animals were divided into two groups (n = 3): Group 1 included clinically healthy animals, Group 2 included animals diagnosed with purulent-catarrhal post-calving endometritis. Metagenomic sequencing was performed using the MiSeq genomic sequencer (Illumina, Inc., USA) with the MiSeq Reagent Kit v3 (Illumina, Inc., USA). Based on the next-generation sequencing of microbiota of endometrial scrapings, 7 phyla of microorganisms were detected in clinically healthy cows and only 4 phyla of microorganisms in cows diagnosed with endometritis. The increase in the proportion of Fusobacteriota taxon bacteria permanently present in endometrial scrapings and the decrease in Bacteroidota phylum bacteria in the group of animals with endometritis could be related to the occurrence of this disease. Bacteria Alloprevotella, Campylobacter, Caviibacter, Falsiporphyromonas, Veillonella present only in the endometrial tissue of sick cows may be the etiological origin of endometritis. In the rumen of animals with endometritis, there was an increase in Bacteroidota phylum microorganisms (p≤0.05) against a decrease in Firmicutes phylum bacteria (p≤0.05) compared to the clinically healthy group. Using the PICRUSt2 software package (v.2.3.0), it was shown that the microbiome of cows diagnosed with endometritis showed inhibition (p≤0.05) of the potential of 9 metabolic pathways compared to healthy animals. This could have negative consequences for the body of animals and be a consequence of metabolic disorders.

Ферментативные и микробиологические процессы в рубце и кишечнике овец при скармливании энерго-антиоксидантного комплекса

Vladimir A. Devyatkin, Evgeniya N. Kolodina, All-Russia Research Institute of animal Husbandry named after Academy Member L. K. Ernst, Dubrovitsy, Russia Abstract The article discusses the possibility and effectiveness of using liquid energy feed based on propylene glycol and glycerin (LEF) in combination with dihydroquercetin and Spirulina Platensis microalgae as an additive to the diet of sheep to optimize inter-daily processes in the pre-pancreas, increase natural resistance, improve intestinal and scar microbiocenosis. It was found that the studied additive contributed to a more intensive hydrolysis of carbohydrates in the rumen of animals due to an increase in the concentration of VFA by 45,2% versus 30,9% in the control, an increase in the content of lysozyme in the blood serum of sheep of the experimental group by 35,4%, (p≥0,1), an increase in phagocytic activity, its index and number by 4,5; 3,9 and 15,8%, respectively, which indicates a more stable cellular immunity, increased resistance of the body to infectious and inflammatory processes, and an increase in natural resistance. The level of lacto- and bifidobacteria was 15,4–17,0% higher (p≥0.001), and yeast-like microorganisms and molds, respectively, were 7,6% and 17,3% lower, which positively affected the microbiocenosis of the intestines of animals.

The effect of season on in vitro degradability and fermentability of feeds in red deers’ (Cervus elaphus L.) rumen fluid

Transition from summer to winter changes red deer digestive tract physiology and digestive processes. The objective of the trial was to determine the effects of season on in vitro apparent (ivADMD) and true dry matter (ivTDMD) digestibility, in vitro gas production parameters and short-chain fatty acid synthesis (SCFA) in red deer hinds of eleven substrates naturally occurring in Slovenia (chestnut fruits, acorns of common and sessile oak, two fresh grasses) and those frequently used in supplemental red deer feeding (two grass hays and two grass silages, apple pomace and sugar beet roots). There were no differences in ivADMD, ivTDMD, determined by incubation of feeds in buffered rumen fluid, as there were no differences in majority of gas production parameters between autumn and winter season. Only the parameter “C” (specific gas production rate) was frequently higher (p &lt; 0.05) in winter season than in autumn season. The amounts of SCFA were similar between two seasons. However, the proportion of acetic acid tended to be higher in winter, while the proportions of propionic and butyric acid tended to be higher in autumn than in winter especially in high fibre feeds. On contrary, in high starch feeds such as oak acorns and chestnut fruits, the proportion of propionic acid was higher (p &lt; 0.05) in winter, while of butyric acid in autumn (p &lt; 0.05). Despite the fact that the number of used substrates (n = 11) and animal rumen fluid donors (n = 6) were small, these results indicate a shift in rumen microbial metabolism between autumn and winter season.

Developing Algorithms and a Mathematical Model for Monitoring the Physiological State of Cattle

This study involved theoretical and experimental research at farms with existing hardware and software. Measurements were conducted with non-invasive methods using special bolus transmitters (smaXtec animal care GmbH, Graz, Austria) developed for cow health monitoring. The boluses were introduced orally into the rumen of the studied cows. Algorithms and mathematical models were constructed for identifying estrus, calving and illnesses, and for monitoring feed and water consumption. Initial data were imported from a standard file, compatible with other applications (CSV table). Additionally, correlations were analyzed between temperature indicators, the rumen pH and the motor activity of the cattle. Illustrations include plots of the main vital factors and the correlated functions, and a screenshot of the software working console. Also included are tables with the results for each cow, the average values and the RMS deviation. The mathematical model developed is a set of algorithms and calculation results. Code for its implementation was written in Matlab R2019b and is attached to this report. This mathematical model may be used to process and interpret data obtained by boluses put into the rumen of animals.&#x0D; Keywords: cattle, rumen acidity, temperature, motor activity, estrus, calving

A diet supplemented with hazelnut skin changes the microbial community composition and the biohydrogenation pattern of linoleic acid in the rumen of growing lambs

The reuse of by-products from the agro-industry in animal feeding is desirable to increase the sustainability of the productions. Hazelnut skin is a by-product of the food industry and due to the high content in crude fat and phenolic compounds can be potentially used in ruminants’ diet. In this study, we characterised and compared the microbial communities of rumen digesta (RD) from lambs fed a diet supplied with hazelnut skin vs. a control diet. Microbial DNA was extracted and high-throughput sequencing of 16S rRNA gene amplicons was performed. Six genera ([Eubacterium] nodatum group, Acidaminococcus, Dialister, Erysipelotrichaceae UCG-002, Megasphaera, and Olsenella) showed a positive correlation with the concentration of C18:1 t10, and their relative abundance was higher in the RD from lambs fed the control diet, compared to the RD from lambs fed the diet supplied with hazelnut skin. The results suggest that the relative abundance of microorganisms correlated to C18:1 t10 production in the rumen of animals fed a concentrate-based diet can be reduced by the administration of hazelnut skin. Highlights A diet with hazelnut skin affected the microbial community in the rumen of lambs The relative abundance of the genus Dialister decreased with hazelnut skin Administration of hazelnut skin can be a strategy to reduce the C18:1 t10/t11 ratio

Animal, feed and rumen fermentation attributes associated with methane emissions from sheep fed brassica crops.

Methane emissions from ruminants enhance global warming and lead to a loss of feed energy. The emissions are low when fed brassica crops, but the factors contributing to low emissions are unknown. A meta-analysis was conducted with individual animal data collected from seven experiments. In these experiments, methane emissions were measured using respiration chambers. Animal characteristics, feed chemical composition and rumen fermentation parameters were included for the analysis using multiple regression models. Feed intake level, animal live weight and age were animal factors that were weakly and negatively related to methane yield (g/dry matter intake). The duration in which sheep were fed brassica crops was a significant contributor in the model, suggesting that the effect on emissions diminishes with time. Among a range of feed chemical composition characters, acid detergent fibre and hot-water-soluble carbohydrate contributed significantly to the model, suggesting that both structural and soluble carbohydrates affect methane formation in the rumen. There was no significant correlation between the concentration of sulphate in brassicas and emissions, but nitrate was moderately and negatively correlated with methane yield (r=-.53). Short-chain fatty acid profiles in the rumen of animals fed brassicas were different from those fed pasture, but these parameters only moderately correlated to methane emissions (r=.42). Feeding forage rape resulted in low rumen pH. The pH before morning feeding was strongly correlated to methane yield (r=.90). Rumen pH, together with microbial communities mediated by pH, might lead to low emissions. Bacteria known to produce hydrogen were relatively less abundant in the rumen contents of brassica-fed animals than pasture-fed animals. In conclusion, animal and feed factors, rumen fermentation and microbial communities all affect methane emissions to some extent. The interactions of these factors with each other thus contribute to methane emissions from brassica-fed sheep.

Rumen digestion and productivity of bulls when using linseed cake and choline

We have studied the peculiarities of the processes of rumen digestion in bulls while feeding them linseed cake in combination with the “protected” form of choline. When linen cake and choline were included in the diet, the most favorable conditions for the development of microorganisms were created in the rumen of animals, which had an impact on the growth of live weight.

Development of a Technology for the Directed Modification of Fatty Acid Composition of Beef in Grass-Fed Feeding

The article presents the results of the influence of studying the formation of a fatty acid profile in cattle meat using forage herbs rich in secondary metabolites (polyphenol oxidase, saponins, tannins and catecholamines) on lipolysis and biohydrogenation in animal rumen. The experiment planning matrix was performed using the Latin square method. The main factor studied was the effect of polyphenol oxidase on biohydrogenation processes in animals. Based on the studies, recommendations are made on the optimal composition of grassland in the pastures of the South of Russia in order to improve the fatty acid composition of beef.

Condensed Tannins in Forages Diverse, Poorly Understood

Wayne Zeller, of the U.S. Dairy Forage Research Center, recently reviewed the state of CT research in Crop Science (http://doi.org/10.2135/cropsci2018.05.0323). He stresses that CTs are not monolithic, but rather vary widely in their size and structure, and describes the current methods for purifying and studying CTs, along with each method's limitations. Just as the amino acids that comprise proteins can be combined in nearly infinite combinations and configurations, the flavan-3-ols that comprise CTs can be combined in various ways. The resulting CT molecules are characterized by the way the flavan-3-ol subunits are linked as well as by stereochemistry, hydroxylation patterns, and the addition of other functional groups. Most of the CTs in common forage species are comprised of four main flavan-3-ols that can be bonded to each other in a combination of linear or branched formations (see illustration above). Even CTs with the same components can have them linked in different order, and each plant contains “an extremely diverse set of structures,” according to Zeller. These are not currently separable by available methods, and thus are studied as a mixture. The formation of CT–protein complexes is impacted by the structures of both the CT and the protein in question as well as the pH, the isoelectric point (pI) of the protein, and the temperature. Formation of CT–protein complexes is known to rely on both hydrogen-bonding and hydrophobic interactions although it is not clear which factor is paramount or occurs first. Condensed tannins with more hydroxyl groups or other functional groups available for hydrogen bonding bond to proteins more effectively, and Zeller points out that they tend to be more effective anti-parasitic agents. Protein precipitation capacity and enzyme inhibition have been demonstrated to increase along with the size of the CT. Other CT structural features that affect protein binding and precipitation include type of linkages between the flavan-3-ol subunits and whether hydroxyl groups on these subunits are derivatized. Pure CTs are highly desired for meaningful experimental results, but they are difficult to obtain. High-performance liquid chromatography (HPLC) can yield only small amounts of pure CTs, and it is expensive and labor intensive. Some researchers have used Sephadex LH-20 as an adsorbent resin to purify CTs, but these CT samples are generally contaminated with carbohydrates and lipids. Moreover, these techniques may oxidize CTs, and thus provide artefactual components when samples are analyzed. If a sample can be obtained, nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry, and other methods can be used to start to elucidate the structure of the CT under investigation. Farmers want to use CTs and/ or CT-containing forages to improve the health of their ruminants and the productivity and sustainability of their farms. However, given that CTs are structurally so diverse, determining how they interact with proteins is difficult to define. Studies must be done not only on how CT structure affects protein precipitation in vitro, but also on how that translates to protein release during the pH changes between an animal's rumen, abomasum, and hindgut. Zeller suggests studies to determine how the other components in forage, like carbohydrates and lipids, affect CT–protein interactions as well as studies examining the interactions between CTs and an animal's microbiome population and any impacts they might have on the animal's health and productivity. Even when a plant's CT content is accurately measured, structural information is still required to assess any biologically relevant activity. The CT content and structure of a forage can be affected not only by the plant's cultivar, but by its harvest time, preservation method, and even storage time. Condensed tannin content must therefore be measured anew each time stored feed is to be used. Only in this way can we determine the best way to utilize CTs to promote healthy animals and healthy farms, according to Zeller. “We need the right level of CTs to get the most benefit,” he says. “Too much CT binds up all of the forage protein, so none will be available to feed the animal's microbiome. There are many papers reporting on CTs, but people don't know the content or the structure, and those molecular details matter.” Read the full Crop Science article, “Activity, Purification, and Analysis of Condensed Tannins: Current State of Affairs and Future Endeavors” at http://doi.org/10.2135/cropsci2018.05.0323.

Beneficial effects of rumen-protected methionine on nitrogen-use efficiency, histological parameters, productivity and reproductive performance of ruminants

Providing essential amounts of balanced nutrients is one of the most vital aspects of livestock production. Among nutrients, protein has an essential role in many physiological functions of animals. Amino acids in needs for both high and medium yielding ruminant animals are not fully covered by microbial degraded feed sources in the rumen of animals, and they must be met by protecting the proteins from being broken down in the rumen; hence, the dietary supplementation of rumen-protected proteins (RPP), including mainly rumen-protected methionine (RPM), became imperative. Many researchers are interested in studying the role of (RPM) in ruminant animals concerning its effect on milk yield, growth performance, digestibility, dry matter intake and nitrogen utilization efficiency. Unfortunately, results obtained from several investigations regarding RPM indicated great fluctuation between its useful and useless effects in ruminant nutrition particularly during early and late lactation period; therefore, this review article may be helpful for ruminant farm owners when they decide to supplement RPM in animal’s diet. Conclusively, supplementation of RPM often has a balanced positive influence, without any reported negative impact on milk yield, growth performance and blood parameters especially in early lactating ruminant animals and when used with the low crude protein diet.