Rumen Fermentation Pattern Research Articles

Effects of Xylanase and Bacterial Inoculants on In Vitro Rumen Fermentation Pattern of Seasonal Pasture Hay and Green Maize Based Silage

The present study was conducted to evaluate the effects of xylanase and bacterial inoculants on in vitro rumen fermentation pattern of seasonal pasture hay and green maize based silage. Different silages were prepared by using green maize fodder and seasonal pasture hay in the proportion of 10:0 & 7:3 ratio in plastic jars of 3 kg capacity by adding common salt @ 0.5%, urea @ 1% and molasses @ 1.5% in each silage with seven different treatments, viz., Control (only green maize), PH (green maize and seasonal pasture hay in 7:3 ratio), X (PH added with xylanase), LP (PH added with L. plantarum), LF (PH added with L. fermentum), LPLF (PH added with both bacterial inoculants) and XLPLF (PH added with xylanase and both bacterial inoculants). Xylanase, L. plantarum and L. fermentum were used @ 1500 IU/g, 1 x 106 cfu/g and 2 x 106 cfu/g, respectively. All silages were used for in vitro study after 45 days of ensiling. None of the additives affected rumen pH. IVDMD (in vitro dry matter degradability ) was found significantly (p<0.05) higher in X, XLPLF and LPLF silages. All additives significantly (p<0.01) increased IVOMD (in vitro organic matter degradability) except LF silage as compared to PH silage. Values for total gas production and TVFA (Total volatile fatty acids) production were significantly (p<0.001) increased during in vitro rumen fermentation and that of PF (partitioning factor) were significantly (p<0.001) decreased in all additives inoculated silages as compared to PH silage. Content of NH3-N (Ammonia nitrogen) was significantly (p<0.001) higher in LP silage and that of total N was significantly (p<0.001) higher in X, LP, XLPLF silages as compared to PH silage during in vitro study. It could be concluded that xylanase and lactic acid bacterial (LAB) inoculants improved rumen fermentation quality of silage. Among all additives, xylanase is the best silage additive to improve in vitro rumen fermentation pattern.

In vitro rumen fermentation pattern: insights from concentrate level and plant oil supplement.

The addition of oil to ruminant diets and oil fatty acid profiles are major factors that negatively affect ruminal fermentation, while increased forage level attenuates the adverse effects. The aim of this study was to determine the effects of oil source supplementation and concentrate level in the diet on in vitro ruminal fermentation kinetics. Pomegranate, garlic or sunflower oils were added (2 % dry matter (DM) basis) to the diets containing 40 % or 60 % (DM basis) concentrates. In vitro gas production parameters, pH, ammonia nitrogen concentration and total protozoa count were measured. Additionally, metabolizable energy (ME), short-chain fatty acid (SCFA) production and organic matter digestibility (OMD) were determined. Rumen fermentation parameters and protozoal population counts were analyzed as a completely randomized design with a 2 3 factorial arrangement of treatments, and gas production parameters were analyzed as a 2 3 factorial arrangement in a randomized block design. The results showed that the HCPO (high (60 %) concentrate diet containing pomegranate oil) and HCSO (high (60 %) concentrate diet containing sunflower oil) diets produced the highest (5.40 mg dL ) and lowest (2.61 mg dL ) concentrations of NH -N ( ), respectively. Total protozoa count tended ( ) to be highest in HCPO and lowest in HCSO diets (5.10 vs. 4.81Log10 g digesta). No interaction effects between the concentrate level and oil source were found on in vitro gas production parameters, pH, estimated ME, SCFA and OMD, and Entodinium and Diplodinium populations ( ). It is concluded that dietary supplementation with highly unsaturated oil from three different sources at 2 % level (DM basis) had no apparent effects on in vitro ruminal fermentation patterns.

Effect of feeding detoxified waste bread in total mixed ration on nutrient utilization and rumen fermentation pattern in adult buffaloes

Effect of feeding detoxified waste bread in total mixed ration on nutrient utilization and rumen fermentation pattern in adult buffaloes

Effect of Dietary Supplementation of Chromium and Yeast on in vitro Dry Matter Degradability and Rumen Fermentation Pattern

Background: Yeast (Saccharomyces cerevisiae), widely used probiotics, was found to increase the utilization of fiber and improve the production in ruminants. The concept of chromium (Cr) supplementation has also received a great deal of attention since past decade, as Cr could have supra-physiological benefits for domestic livestock. The present in vitro experiment was conducted to investigate the effect of dietary chromium and yeast supplementation on in-vitro dry matter degradability and rumen fermentation by rumen simulation technique. Methods: The yeast (Saccharomyces cerevisiae) (Y) (5 x 109 CFU /kg) and chromium (Cr) (1.5 mg/kg) supplementation to sorghum stover based complete diets (Basal diet: 10.58% CP) either alone or in combination on in vitro nutrient degradability and rumen fermentation was assessed by rumen simulation technique. Result: Chromium supplementation alone did not affect the cumulative degradability and effective dry matter degradability in vitro compared to BD. Yeast supplementation enhanced (P less than 0.01) in vitro DM degradability on 12, 24 and 48 h, effective DM degradability and lowered (P less than 0.01) ammonia nitrogen level in comparison to control. When compared to control, combination of yeast and Cr positively affected rumen fermentation pattern and in vitro nutrient degradability but no further improvement was observed compared to only yeast supplementation in diet.

Contribution of gut microbiomes and their metabolomes to the performance of Dorper and Tan sheep.

Livestock is an excellent source of high nutritional value protein for humans; breeding livestock is focused on improving meat productivity and quality. Dorper sheep is a distinguished breed with an excellent growth performance, while Tan sheep is a Chinese local breed famous for its delicious meat. Several studies have demonstrated that the composition of gut microbiome and metabolome modulate host phenotype. In the present study, we performed 16S amplicon sequencing and metabolomic analyses of the rumen and hindgut microbiome of 8-month-old Dorper and Tan sheep, raised under identical feeding and management conditions, to explore the potential effects of gut microbiome and its metabolites on growth performance and meat quality. Our study identified Lactobacillus, a marker genus in the rumen, to be significantly associated with the levels of fumaric acid, nicotinic acid, and 2-deoxyadenosine (P-value < 0.05). Statistical analysis showed that nicotinic acid was significantly negatively correlated with body weight (P-value < 0.01), while 2-deoxyadenosine was significantly positively correlated with fatty acids content (P-value < 0.05). There was a biologically significant negative correlation between Phascolarctobacterium and deoxycytidine levels in the hindgut. Deoxycytidine was significantly positively correlated with body weight, protein, and amino acid content. Differences in rumen fermentation patterns that are distinctive among breeds were identified. Tan sheep mainly used Lactobacillus and fumaric acid-mediated pyruvic acid for energy supply, while Dorper sheep utilize glycogenic amino acids. The difference of iron metabolism in the hindgut of Dorper sheep affects lipid production, while Phascolarctobacterium in Tan sheep is related to roughage tolerance. The accumulation of nucleosides promotes the growth performance of Dorper sheep. These findings provide insights into how the microbiome-metabolome-dependent mechanisms contribute to growth rate and fat contents in different breeds. This fundamental research is vital to identifying the dominant traits of breeds, improving growth rate and meat quality, and establishing principles for precision feeding.

Yeast Products Mediated Ruminal Subenvironmental Microbiota, and Abnormal Metabolites and Digestive Enzymes Regulated Rumen Fermentation Function in Sheep.

Yeast products (YP) are commonly used as rumen regulators, but their mechanisms of action are still unclear. Based on our previous studies, we questioned whether yeast products would have an impact on rumen solid-associated (SA) and liquid-associated (LA) microorganisms and alter rumen fermentation patterns. Thirty 3-month-old male sheep weighing 19.27 ± 0.45 kg were selected and randomized into three groups for 60 days: (1) basal diet group (CON group), (2) basal diet add 20 g YP per day (low YP, LYP group) and (3) basal diet add 40 g YP per day (high YP, HYP group). The results demonstrated that the addition of YP increased rumen cellulase activity, butyrate and total volatile fatty acid (TVFA) concentrations (p &lt; 0.05), while it decreased rumen amylase activity and abnormal metabolites, such as lactate, lipopolysaccharides (LPS) and histamine (HIS) (p &lt; 0.05). Metagenomic analysis of rumen microorganisms in three groups revealed that YP mainly influenced the microbial profiles of the SA system. YP increased the relative abundance of R. flavefaciens and decreased methanogens in the SA system (p &lt; 0.05). With the addition of YP, the abundance of only a few lactate-producing bacteria increased in the SA system, including Streptococcus and Lactobacillus (p &lt; 0.05). However, almost all lactate-utilizing bacteria increased in the LA system, including Megasphaera, Selenomonas, Fusobacterium and Veillonella (p &lt; 0.05). In addition, YP increased the abundance of certain GHs family members, including GH43 and GH98 (p &lt; 0.05), but decreased the abundance of some KEGG metabolic pathways involved in starch and sucrose metabolism, biosynthesis of antibiotics and purine metabolism, among others. In conclusion, the addition of YP to high-concentrate diets can change the abundance of major functional microbiota in the rumen, especially in the solid fraction, which in turn affects rumen fermentation patterns and improves rumen digestibility.

Effect of Heat Stress on Rumen Microbial Diversity and Fermentation Pattern in Buffalo

In this study, changes in rumen microbiome and fermentation were examined during heat stress (HS) in buffaloes. Six buffalo heifers were exposed to thermoneutral ( THI = 72 ) and HS ( THI = 87 – 90 ) conditions for 6 h between 10 AM and 4 PM for 21 days in the climatic chamber. A digestibility trial with four-day collection period was conducted at the end of the study, and rumen liquor was collected on day 21. At the phylum level, an increased ( p &lt; 0.05 ) abundance of Firmicutes and a decreased ( p &lt; 0.05 ) abundance of Proteobacteria and Planctomycetes were observed during HS compared to thermoneutral conditions. The abundance of 6 different genera of phylum Firmicutes, YRC22 (phylum Bacteroidetes), and Stenotrophomonas (phylum Proteobacteria) was increased ( p &lt; 0.05 ), whereas B. firmus, Lysinibacillus, Bacteroides unclassified genus (family Enterobacteriaceae), and Methanobrevibacter decreased ( p &lt; 0.05 ) during HS compared to control. Eight new genera from four different phyla were detected after HS exposure, whereas one genus was not detected in the rumen after HS exposure, which was present during thermoneutral conditions. Dry matter intake, volatile fatty acid concentration, and digestibility did not change ( p &gt; 0.05 ) during HS. It can be concluded that the resilience of the rumen microbial population invokes adaptive responses by changing their abundance to minimize the adverse effects on fermentation and digestibility in buffalo heifers.

Effects of the density of extruded pellets on starch digestion kinetics, rumen fermentation, fiber digestibilityand enteric methane production in dairy cows.

Dynamics of starch digestion in dairy cows fed extruded pellets differing in physical functional properties were investigated by measuring starch digestibility, post-prandial rumen fermentation patterns, and post-prandial duodenal starch appearance. Additionally, starch digestion effects on neutral detergent fiber (NDF) digestibility and methane (CH4 ) emission were studied. Pure barley was extruded to produce three treatments having pellets of either low-density (LD), medium-density (MD)or high-density (HD). The experiment was conducted in a 3 × 3 Latin square design using three lactating Danish Holstein cows fitted with ruminal, duodenaland ileal cannulas. After the allocation of experimental concentrate directly into the rumen through the rumen cannula, cows were fed a basal diet low in starch. Eight samples were collected on equal time intervals (9 h) from duodenal digesta, ileal digestaand feces (grab sample) to determine digestibility. For post-prandial rumen fermentation patterns, four sample sets of rumen dorsal, medialand ventral fluid were taken from each cow, whereas for post-prandial duodenal starch appearance, 14 samples of duodenal chyme were obtained from each cow relative to morning feeding of experimental concentrate at 07:00 h. Ruminal, small intestinal, hindgutand total tract digestibility of starch did not differ among treatments. Similarly, NDF digestibility and CH4 emission also remained unaffected by treatments. However, compared with the LD and MD treatments, the HD treatment showed higher acetate: propionate ratio at all positions in the rumen and a higher post-prandial duodenal starch appearance. This indicates lower ruminal starch degradation (RSD) and higher starch flow into the small intestine for HD treatment. In conclusion, the current study indicates that pellets' physical properties can manipulate RSD, where pellets with high densityand fluid stability can partly shift starch digestion from the rumen to the small intestine. Indeed, further investigations are needed.

Implications of phyto-feed additives supplementation in buffalo calves on rumen fermentation pattern and microbial population

Natural phyto-feed additives have been identified as a potential rumen fermentation modifier by in vitro studies and by few short-term in vivo trials. However, information on impact on animal performance by their long-term administration is still inadequate. In light of this, the present study was undertaken to examine the rumen fermentation pattern, rumen microbial enzymes and microbial profiles as influenced by long term supplementation of phyto-feed additives to buffalo calves. A six months feeding trial was conducted on 20 male buffaloes (165±4 kg body weight), divided into four groups and fed on diet supplemented with no additive (T0, control), with feed additive FAI @ 1% of dry matter intake (DMI) (T1), with FAII @ 1 ml/kg DMI (T2) and with FAI and FAII switched alternatively after every 15 days (T3). No significant effect was observed on rumen fermentation pattern as well as carboxymethylcellulase, avicelase, xylanase, acetyl esterase, and protease activities in the rumen of buffalo calves. The population density of methanogens, fungi, Ruminococcus flavefaciens, and R. albus decreased significantly in T3 where FAI and FAII were fed alternately, but Fibrobacter succinogenes decreased significantly in T2 where FAII was fed. When compared to the control, the microscopic count of protozoa decreased in all the three supplemented groups. It can be concluded that rumen fermentation, including rumen metabolites and microbial enzymes, were unaffected; however, phyto-feed additives exhibited changes in rumen microbes.

Defatted silkworm pupae meal as an alternative protein source for cattle.

Silkworm pupae meal (SWP) is a protein-rich by-product of the silk reeling industry, available in a significant quantity. However, there has been little and insignificant research into the use of SWP in ruminants to date. In this view, the present study was conducted in two phases to evaluate the effect of different inclusion levels of defatted silkworm pupae meal (DSWP) on rumen fermentation, microbial protein synthesis and nutrient utilisation in cattle fed on finger millet straw (FMS)-based diet. Four isonitrogenous concentrate mixtures (CM) were prepared with DSWP replacing soybean meal (SBM) protein at 0 (T0), 10 (T1), 20 (T2) and 30% (T3). In phase I, a rumen fermentation experiment was conducted in a 4 × 4 Latin square design using four crossbred steers to study the effect of different levels of DSWP on rumen fermentation. No significant difference (P > 0.05) was observed in rumen fermentation parameters such as pH, ammonia nitrogen (NH3-N) and total volatile fatty acids (VFA) among the experimental groups. In phase II, the digestibility trial was conducted in 20 crossbred cattle (311.2 ± 4.81kg), which were divided into four experimental groups of five animals each in a completely randomised design to study the effect of different rations (T0, T1, T2, T3) on microbial protein synthesis and nutrient utilisation. The intake and digestibility of nutrients, excretion of urinary purine derivatives and microbial protein synthesis were not significantly different among the experimental groups. In addition, feeding DSWP revealed no significant (P > 0.05) change in the blood biochemical parameters of animals. Furthermore, at the same price as SBM, DSWP provides two units more crude protein. Therefore, the results of the present study indicated that DSWP can be incorporated into the ration of cattle up to 30% by replacing SBM without affecting rumen fermentation pattern and nutrient utilisation.

Does the timing of pasture allocation affect rumen and plasma metabolites and ghrelin, insulin and cortisol profile in dairy ewes?

A study was undertaken to assess the impact of the timing of grazing on rumen and plasma metabolites and some metabolic hormones in lactating dairy sheep allocated to an Italian ryegrass (Lolium multiflorum Lam) pasture in spring for 4 h/d. Twenty-four mid lactation Sarda ewes stratified for milk yield, body weight, and body condition score, were divided into four homogeneous groups randomly allocated to the treatments (2 replicate groups per treatment). Treatments were morning (AM, from 08:00 to 12:00) and afternoon pasture allocation (PM, from 15:30 to 19:30). Samples of rumen liquor (day 39) and blood plasma (days 17 and 34 of the experimental period) were collected before and after the grazing sessions. Moreover, on days 11 and 35, grazing time was assessed by direct observation and herbage intake measured by the double weighing procedure. Grazing time was longer in PM than AM ewes (P < 0.001) but herbage intake was undifferentiated between groups. The intake of water-soluble carbohydrates at pasture was higher in PM than AM ewes (P < 0.05). The post-grazing propionic and butyric acid concentration, as measured on day 39, were higher in PM than AM ewes (P < 0.05). The basal level of glucose on day 34 and insulin (on both sampling days) were higher in PM than AM (P < 0.05). The opposite trend was detected for non-esterified fatty acids (P < 0.05, day 34) and urea (both days). Pasture allocation in the afternoon rather than in the morning decreased plasma concentration of ghrelin (P < 0.001) and cortisol (P < 0.001), with a smoothed trend on day 34 in the latter variable. To conclude, postponing the pasture allocation to afternoon increased the intake of WSC, favoring a glucogenic pattern of rumen fermentation and a rise of glucose and insulin levels in blood, although these effects were not consistent across the whole experimental period. Moreover, the afternoon grazing decreased the level of cortisol and ghrelin, suggesting a higher satiation-relaxing effect.

Diet Shift May Trigger LuxS/AI-2 Quorum Sensing in Rumen Bacteria.

Recent studies have revealed that LuxS/AI-2 quorum sensing (QS) is the most universal cell-to-cell communication in rumen bacteria; however, it remains unknown how they respond to nutritional stress from a diet shift. This study aimed to explore whether a diet shift could trigger rumen bacterial LuxS/AI-2 QS and its influences on rumen fermentation characteristics and bacterial community diversity and composition. A total of fifteen Hu sheep were selected to undergo a pre-shift diet (Pre, concentrate to forage ratio 75:25) for one month and then abruptly switch to a post-shift diet (Post, concentrate to forage ratio 49:51). Results showed that the serum cortisol and immunoglobulin G concentrations were higher in Post than in Pre (p < 0.05). The microbial density, AI-2 concentration, biofilm formation, and the gene expression of ftsH were higher in Post when compared with Pre (p < 0.05), whilst the gene expression of luxS tended to be lower in Post (p = 0.054). The molar concentration of valerate and fermentation efficiency decreased after the diet shift, while the acetate to propionate ratio and the molar proportion of butyrate were higher in Post compared to Pre (p < 0.05). Moreover, the diet shift increased the richness of ruminal bacteria and the relative abundances of Roseburia, Prevotellaceae UCG-001, and Lachnospira, and decreased the relative abundances of Prevotella, Megasphaera, and Dialister (p < 0.05). A difference in trends was also observed in an analysis of similarity (R = 0.1208 and p = 0.064). This study suggests that a diet shift could trigger rumen bacterial LuxS/AI-2 QS by altering microbial density, AI-2 concentration, biofilm formation, and related gene expression, as well as affect the rumen fermentation pattern and bacterial community diversity and composition. This study may provide insight into a potential strategy for relieving nutritional stress via regulating bacterial communication.

Yak rumen microbiome elevates fiber degradation ability and alters rumen fermentation pattern to increase feed efficiency.

Rumen microbes play an important role in ruminant energy supply and animal performance. Previous studies showed that yak (Bos grunniens) rumen microbiome and fermentation differ from other ruminants. However, little is understood about the features of the rumen microbiome that make yak adapted to their unique environmental and dietary conditions. This study was to investigate the rumen microbiome and metabolome to understand how yak adapt to the coarse forage and harsh environment in the Qinghai-Tibetan plateau. Nine female Qaidam yellow cattle (Bos taurus), 9 dzomo (hybrids of cattle and yak) and 9 female plateau yak (B. grunniens), about 5 to 6 years old, were used in this study. Rumen fermentation parameters, fibrolytic enzyme activities, and rumen metataxonomic were determined. Then 18 (6 samples per group) were selected for rumen metagenomic and metabolome analysis. Metataxonomic analysis revealed that the rumen microbiota was significantly different among plateau yak, Qaidam yellow cattle, and dzomo (P < 0.05). Metagenomic analysis displayed a larger gene pool encoding a richer repertoire of carbohydrate-active enzymes in the rumen microbiome of plateau yak and dzomo than Qaidam yellow cattle (P < 0.05). Some of the genes encoding glycoside hydrolases that mediate the digestion of cellulose and hemicellulose were significantly enriched in the rumen of plateau yak than Qaidam yellow cattle, but glycoside hydrolase 57 that primarily includes amylases was abundant in Qaidam yellow cattle (P < 0.05). The rumen fermentation profile differed also, Qaidam yellow cattle having a higher molar proportion of acetate but a lower molar proportion of propionate than dzomo and plateau yak (P < 0.05). Based on metabolomic analysis, rumen microbial metabolic pathways and metabolites were different. Differential metabolites are mainly amino acids, carboxylic acids, sugars, and bile acids. Changes in rumen microbial composition could explain the above results. The present study showed that the rumen microbiome of plateau yak helps its host to adapt to the Qinghai-Tibetan plateau. In particular, the plateau yak rumen microbiome has more enzymes genes involved in cellulase and hemicellulase than that of cattle, resulting higher fibrolytic enzyme activities in yak, further providing stronger fiber degradation function.

N-carbamylglutamate improves feed conversion efficiency, feed digestibility and immunity status in finishing Holstein bulls

N-carbamylglutamate (NCG), an alternative of arginine, has been applied to improve nitrogen utilization by promoting the synthesis of urea and nitric oxide in dairy cows. However, scarce data on the effects of NCG on bulls exist, especially on antioxidant and immunity status and rumen fermentation. This study was conducted to investigate the effects of NCG on growth performance, nutrient digestibility, antioxidant and immunity status, and rumen fermentation patterns in finishing Holstein bulls. Forty-five healthy Holstein bulls with initial body weight (BW) of 478 ± 13.7 kg were assigned to a randomized complete design with 3 treatments. The NCG supplementation was 0, 15, or 25 g/d per bull in the three different treatments. The experimental period was 122 d, after a-7 d adaptation period. Although the final BW and average daily gain were not affected by NCG supplementation, dry matter intake tended to decrease linearly, and feed to gain ratio decreased linearly with increasing NCG supplementation. The apparent total tract digestibility of dry matter, organic matter, non-fiber carbohydrate were not affected, whereas a linear increase was observed in acid detergent fiber and neutral detergent fiber digestibility, and a quadratic increase was observed in crude protein digestibility. The concentration of total protein and nitric oxide was greater in bulls fed 15 g/d and 25 g/d NCG than in control. The serum total anti-oxidant capacity increased quadratically with increasing NCG supplementation, and peaked at 15 g/d. The interleukin-2 concentration significantly increased in bulls fed 15 g/d NCG. The concentration of total volatile fatty acids was greater in bulls fed 15 g/d NCG compared to the other groups. In conclusion, NCG supplementation in finishing Holstein bulls may be beneficial for the improvement of feed efficiency, by increasing feed digestibility and improving antioxidant and immunity status. The most optimal dose appeared to be 15 g/d.

Effects of Barley Starch Level in Diet on Fermentation and Microflora in Rumen of Hu Sheep.

Simple SummaryIncreasing the starch level in the diet of ruminants can promote rumen fermentation to a certain extent and improve production performance. However, the degradation of rapidly fermentable carbohydrates in the rumen can lead to the accumulation of large amounts of organic acids (mainly volatile fatty acids and lactic acid), increasing the risk of subacute ruminal acidosis (SARA) in high-yielding ruminants. By changing the fermentation sites of rapidly fermentable carbohydrates, the rumen environment and feed efficiency could be effectively improved. The object of this study was to explore the effects of replacing corn starch with barley starch in the diet of Hu sheep on the fermentation and microflora in the rumen. Our results showed that, starch in the diet cannot be derived entirely from barley, and it is feasible to replace 33% of the corn with barley in the diet for Hu sheep.This study aimed to explore the effects of different levels of barley starch instead of corn starch on the rumen fermentation and microflora when feeding a corn-based diet to Hu sheep. Thirty-two male Hu sheep equipped with permanent rumen fistulas were selected and fed in individual metabolic cages. All sheep were randomly divided into four groups (eight sheep in each group) and fed with four diets containing a similar starch content, but from different starch sources, including 100% of starch derived from corn (CS), 33% of starch derived from barley + 67% of starch derived from corn (33 BS), 67% of starch derived from barley + 33% of starch derived from corn (67 BS) and 100% of starch derived from barley (100 BS). The experimental period included a 14 d adaptation period and a 2 d continuous data collection period. The results showed that the molar proportions of acetate, isobutyrate, butyrate and isovalerate and the ratio of acetate to propionate in the 67 BS and 100 BS groups decreased compared with the CS and 33 BS groups (p < 0.001), while the molar proportions of propionate and valerate increased (p < 0.001). The combination of 33% barley starch and 67% corn starch in the diet improved the production of TVFAs (p = 0.007). The OTUs and Shannon indexes of the CS and 33 BS groups were higher than the 67 BS and 100 BS groups (p < 0.001), and the Chao1 and Ace indexes were higher than the 100 BS group (p < 0.05). In addition, the 33 BS group had increased the relative abundances of Bacteroidetes, Prevotella and Ruminococcus and the abundances of Fibrobacter succinogenes, Ruminococcus flavefaciens, Streptococcus bovis, Selenomonas ruminantium and Prevotella brevis relative to the CS group (p < 0.05). These results indicate that the substitution of 33% of the CS with BS did not change the rumen fermentation pattern relative to the CS group, and increased the richness and diversity of the rumen microbes in Hu sheep compared with other two starch substitute groups.

The effect of feeding a mix of condensed and hydrolyzable tannins to heifers on rumen fermentation patterns, blood urea nitrogen, and amino acid profile

The objective of this pilot study was to begin to evaluate the effect of feeding a mix of condensed and hydrolyzable tannins to heifers on rumen fermentation patterns, blood urea nitrogen (BUN), and amino acid profile. Four growing Holstein-Friesian × Jersey heifers with a mean live weight of 319.5 ± 8.38 kg and a mean body condition score of 4 ± 0.17 out of 10 were used in a cross-over design. Heifers were either orally administered the mixed tannin treatment at 0.15% of daily DMI or a control dose of water whilst consuming perennial ryegrass baleage and soybean meal for 12 days in a cross-over trial. Administration of mixed tannins reduced non-glucogenic volatile fatty acid (VFA) production by 2%, the acetate to propionate (A:P) ratio by 13%, and the relative abundances of specific methanogenic archaea – i.e., Methanobrevibacter and Methanosarcina. The tannin treatment also reduced BUN concentration by 12% in comparison with the control dose of water, which indicates associated reductions in daily urinary nitrogen excretion and therefore environmental impact. The effects of ingestion of mixed tannins on rumen function in this study would be expected to result in a reduction of both methane and urinary nitrogen excretion and thereby reducing the environmental impact of heifers consuming conventional feeds.

Evaluation of Suitability of Buffer to Induce Acidosis on Rice (Oriza sativa) based Diet in RUSITEC

Background: Rice feeding followed in Tamil Nadu for dairy cattle induces acidosis and the effect of acidosis studies through in vitro techniques is desirable to reduce the animal experiment. Since Mc Dougall Buffer neutralizes acidity produced on incubation with rice (Oriza sativa) in semi continuous culture, it is difficult to mimic acidosis in RUSITEC. Hence a study was conducted in RUSITEC with cooked rice incubated for 24 hours to evaluate the effect of diluting Mc Dougall buffer to establish rumen acidosis (pH less than 5.8). Methods: Two treatments were followed with undiluted Mc Dougall Buffer (MDB) and diluting Mc Dougall Buffer (MMDB) as per Mickdam et al. (2016) in RUSITEC experiments with six replicates for each treatment. This experiment was conducted with equivalent weight of test material (Cooked rice on DMB). The pH of artificial buffer was maintained at 7.4 during start of incubation for both buffers. Result: The rumen fermentation pattern for establishment of onset of acidosis due to over feeding of cooked rice was evinced by the onset of acidosis ( less than 5.8 pH) recorded at 3 hours of incubation in MMDB infusion and at 18 hours of incubation in MDB infusion. The concentration of NH3-N declined after acidosis induction; however, it reached its minimum in MMDB at significant difference (p less than 0.05) than MDB at all incubation hours. Total gas production (Methane and Carbon dioxide) was reduced with MMDB incubation. The CH4 proportion declined strongly (p less than 0.01) at all incubation hours in MMDB than MDB. The production of volatile fatty acid was reduced significantly (p less than 0.05) in MMDB at all incubation period compared with MDB. This was based on a significant decrease in the acetate production (p less than 0.05), an increase in the propionate and butyrate production (p less than 0.05). Acidosis challenge resulted in significantly (p less than 0.01) elevated lactate levels in MMDB at all incubation hours which remained high at 24 hours of incubation. Compared to MDB condition, the LPS concentration was largely elevated (p less than 0.01), by 36% on average till 12 hours of incubation, due to severe acidosis condition (pH 4.9) created by MMDB. The early occurrence of acidosis condition in MMDB, increased significantly (p less than 0.01) gram positive organisms in the rumen. The MMDB infusion showed a strong effect on degradation of DM, OM and N and it was decreased, similarly the degradation rate of DM and N was lowest. This study proves that the MMDB is the suitable acidosis inducing buffer for establishing the in vitro models to cooked rice.

Rumen Fermentation and Microbial Nitrogen Supply in Native Sheep Fed Crop Residue based Densified Feed Blocks Varying in Particle Size of Roughage

Background: Roughages with an appropriate particle size are required to maintain the optimum rumen health, fermentation and nutrient digestibility. In this regard, the present study was conducted in sheep to determine the optimum particle size for preparation of complete feed blocks. Methods: Twenty-one adult Deccani rams (19.45±0.80 kg) of 2-3 yrs age were used in a complete randomized design to assess the effect of particle size (PS) of sorghum stover (SS) on rumen fermentation characteristics and microbial nitrogen supply. Rams were divided into 3 groups consisting of 7 animals each and fed complete feed blocks containing 8 mm (SSCFB-8), 12 mm (SSCFB-12) and 16 mm (SSCFB-16) particle sizes of the stover. Rumen liquor was collected using stomach tube from each animal at 0, 2, 4 and 6 h after feeding to assess rumen fermentation pattern. Result: Mean rumen pH was increased (P less than 0.001) with increased PS of the SS in the CFBs and the rams fed SSCFB-12 and SSCFB-16 diets were shown highest (P less than 0.001) pH values. Average ammonia nitrogen concentrations were lower (P less than 0.01) in rams fed SSCFB-16 diet compared to those fed SSCFB-12 or SSCFB-8 diets. The average total volatile fatty acid (TVFA) concentration was decreased with increase in PS of SS in the feed blocks. The rams fed SSCFB-8 diet had shown higher (P less than 0.05) TVFA mean values than those fed SSCFB-12 or SSCFB-16 diets. Microbialnitrogen (g/day, g/kg W0.75) and protein supply (g/day, g/kg W0.75 and g/kg DOMI) was not affected by the PS of sorghum stover in complete feed blocks.Based on the results of the current study the SS ground to 8 mm can be considered as optimum for sheep fed SS based diets.

De-oiled palm kernel cake for stall-fed buffaloes: effect on milk constituents, nutrient digestibility, biochemical parameters, and rumen fermentation.

Palm kernel cake, the main by-product of the palm kernel oil extraction process, is a highly available and low-priced agro-industrial by-product. However, several concerns exist to arriving at a safe inclusion level, especially for buffaloes. Two experiments were conducted to evaluate the effects of feeding de-oiled palm kernel cake (DPKC) to tropical buffaloes. In trial I, four fistulated Murrah buffaloes arranged in a 4 × 4 Latin square design were fed diets containing DPKC inclusions at 0, 15, 30, and 45% levels of compound feed to study their effects on rumen fermentation parameters. Trial II involves feeding twelve lactating buffaloes with DPKC inclusion levels at 0 or 15% of the compound feed to evaluate the effect of DPKC on the nutrient digestibility, serum biochemical constituents, rumen fermentation patterns, and lactation profile. The DPKC diets did not affect rumen pH, TCA-ppt nitrogen, and TVFA proportion; nevertheless, the NH3-N data revealed a decreased trend (P = 0.076). The acetate fraction decreased linearly (P < 0.05) with increased DPKC diets. Replacing the conventional protein sources with DPKC at a 15% level did not influence the nutrient intake and digestibility coefficients. No significant effects were observed for serum biochemical and mineral profiles of the lactating buffaloes fed the DPKC diet. Neither milk yield nor milk constituents (SNF, total solids, density, lactose, protein) were altered with the diets fed, except for milk fat%, which tended to increase (P = 0.092) on feeding DPKC diets. All the lactation parameters varied with time of collection, and diet × time interactions were noticed for fat, density, protein, 6% FCM yield, and butterfat yield. The feed efficiency tended to increase (P = 0.070) in the buffaloes fed DPKC diets. The profit margins were ₹6.07 and ₹1.63 for the DPKC included diets and feed cost per Kg 6% FCMY, respectively. Inconclusion,the inclusion of DPKC in the diet decreases feed cost without affecting the nutrient intakes, digestibility coefficients, serum biochemical and mineral profile, and lactation parameters.

Effect of supplementation of phytogenic feed additives on intake, in vitro fermentation, growth performance and carcass traits in weaned Barbari kids reared under intensive feeding.

Twenty-four weaned male Barbari kids (age 144.67 days; weight 11.99 ± 0.49 kg) were divided equally into three groups (T1, T2, and T3) in order to investigate the effect of supplementation of phytogenic feed additives (herbal mixture) in the complete pelleted feed on growth performance, in vitro rumen fermentation and carcass quality in kids reared under stall-fed condition. Treatment groups were as follows: T1, concentrate mixture (40%) plus arhar (Cajanus cajan) straw (60%) in total mixed ration (TMR) form fed ad libitum; T2, T1 diet in complete feed pellets form fed ad libitum; and T3, T1 diet in complete feed pellets form supplemented with herbal mixture (Tulsi/Haldi/Amla/Arni; ratio 1:1:1:1 on DM basis) at 0.5% in complete feed fed ad libitum. The experimental kids in each group were allowed for feeding for 8 months by following the respective feeding schedule. Rumen fermentation pattern under in vitro system was also studied using the same three diets as substrates. After 240 days of feeding, all goats were slaughtered following standard protocol. Total body weight gain (kg) and average daily gain (ADG, g/day/kid) were 18.57, 22.26, and 23.06 kg, and 79.91, 101.49, and 100.18 g in T1, T2, and T3 treatments, respectively. Pelleting of TMR (T2) and supplementation of herbal mixture in pelleted feed (T3) increased (P < 0.001) average daily weight gain in Barbari kids compared to T1 (TMR). Average dry matter intake (DMI, g/day/kid) during growth trial was greater (P < 0.05) in T3 (1079.17) than T1 (849.76) and T2 (968.76). Feed conversion efficiency was 8.92, 9.48, and 8.68% in T1, T2, and T3, respectively. The difference was statistically non-significant among the treatments. Supplementation of herbal mixture in the complete pelleted substrate had adjunct effect on improvement of TCA-precipitable-N and total VFAs in the incubation medium under in vitro system. Carcass weight (kg) tended to increase in finisher kids under T2 (16.58) and T3 (16.70) than T1 (14.61), but the variation was non-significant. The dressing percentage was similar among three treatments. Similarly, the muscle protein, fat, and cholesterol contents remained unaffected by different dietary treatments. Therefore, it may be concluded that densification of feeds in the form ofcomplete pelleted feed and further supplementation with potential phytogenic feed additives increased total DMI and ADG and tended to enhance meat production potential in finisher Barbari kids without changing the meat chemical composition.