Ruminal Total VFA Concentration Research Articles

PSI-6 Effects of a Postbiotic Program Consisting of Liquid and Solid Saccharomyces Cerevisiae Fermentation Products on Digestibility, Ruminal Fermentation, and Plasma Metabolome of Finishing Beef Steers

Abstract The objective of this study was to determine the effects of a postbiotic feeding program consisting of liquid and solid Saccharomyces cerevisiae fermentation products (SCFP) on digestibility, ruminal fermentation, and plasma metabolome of finishing beef steers. Eight Holstein steers (BW 467 ± 13.9 kg) equipped with rumen cannulas were used in a crossover design study, with 21-d per period and 7-d washout period in between periods. Steers were blocked based on initial BW to one of two treatments: 1) Control, basal diet only (CON), or 2) SCFP, one day feeding of LiquiCare RTU (Diamond V, dosed via rumen cannula at 11 mL/100 kg BW) followed by daily feeding of 12 g NaturSafe (Diamond V, top-dressed). Feed and fecal samples were collected during d 17 to 20 for determination of digestibility and fecal excretion of N, P, Cu and Zn using acid-insoluble ash as an internal marker. Blood samples were collected on d 21 before morning feeding. Rumen fluid samples were collected on d 0, 1, 2, 3, 5 and 21 at 0, 4, 8, or 12 h post morning feeding via rumen cannula. Results were analyzed with the GLIMMIX procedure of SAS 9.4 (SAS, 2022). BW, DMI and digestibility were not affected by treatment. There was a tendency of treatment by period interaction (P = 0.09) on feed efficiency, which was improved by feeding SCFP only in period 1. Feeding SCFP did not affect (P > 0.10) ruminal pH. Feeding SCFP tended to reduce ruminal lactate concentration on d 21 (0.09 vs. 0.02 mM, P = 0.10). Supplementing SCFP reduced ruminal NH3-N concentration on d 2 (4.24 vs. 7.31 mg/dL, P = 0.03) and d 21 (4.86 vs. 6.83 mg/dL, P = 0.04). By feeding SCFP, ruminal total VFA concentration was increased 4-h post-feeding on d 5 (139.7 vs. 126.7 mM, P = 0.01) and numerically increased 4-h post-feeding on d 21 (151.2 vs. 133.3 mM, P = 0.12). For VFA composition, no treatment differences were observed on day 21. However, feeding SCFP reduced (P = 0.01) propionate proportion and increased (P = 0.05) butyrate proportion on day 3. The enriched plasma metabolic pathways (P ≤ 0.05) by feeding SCFP are citric acid cycle, pyrimidine metabolism, glycolysis/gluconeogenesis, retinol metabolism, and inositol phosphate metabolism pathways. Overall, our results indicated potential benefits of the SCFP feeding program on improving ruminal fermentation, preventing acidosis and improving N utilization in the rumen. Furthermore, feeding SCFP enriched several important pathways in lipid, protein, and glucose metabolism, which may improve feed efficiency of energy and protein in finishing beef cattle.

PSI-13 Effects of a Postbiotic Program Consisting of Liquid and Solid Saccharomyces Cerevisiae Fermentation Products on Ruminal Microbiome Composition and Microbial Functions of Finishing Beef Steers

Abstract We assessed the effects of a postbiotic program consisting of liquid and solid Saccharomyces cerevisiae fermentation products (SCFP) on the ruminal microbiome and fermentation characteristics of beef steers. Eight Holstein steers (BW 467 ± 13.9 kg) with rumen cannulas were used in a crossover design study with 21-d per period and 7-d washout in between periods. Steers were blocked based on initial BW and assigned to one of two treatments: 1) Control, basal diet, or 2) SCFP, basal diet plus one day feeding of LiquiCare RTU (Diamond V, Cedar Rapids, IA; dosed via rumen cannula at 11 mL/100 kg BW), followed by daily feeding of 12 g/d NaturSafe (Diamond V, top-dressed). Rumen fluid samples were collected on d 0, 1, 2, 3, 5 and 21 at 0, 4, 8, or 12 h post morning feeding via rumen cannula for pH, VFA and NH3-N analyses. Samples collected at 4 h post morning feeding on d 0, 2 and 21 were subjected to DNA extraction and shotgun Nanopore sequencing to determine microbiome composition and carbohydrate active enzymes (CAZy) functional potential. Statistical model included the fixed effects of treatment, period, day and their interactions and random effect of animal. Feeding SCFP tended to reduce ruminal lactate (0.09 vs. 0.02 mM, P = 0.10), and reduced ruminal NH3-N (4.86 vs. 6.83 mg/dL, P = 0.04) on d 21. Ruminal total VFA concentration was increased (P = 0.01) by feeding SCFP 4-h post-feeding on d 5 and numerically increased 4-h post-feeding on day 21 (133.3 vs. 151.2 mM, P = 0.12). Treatments did not affect species or CAZy alpha- and beta-diversity. Steers received liquid postbiotic on d 2 exhibited a positive correlation (P < 0.05) between propionate molar proportion and glycosyl transferases (GT), glycoside hydrolases (GH), carbohydrate esterases, and carbohydrate binding modules (CBM); and a negative correlation (P < 0.05) between acetate molar proportion and polysaccharide lyases, GT, GH, and CBM, which was not observed in Control. Additionally, SCFP steers had higher (P = 0.05) CBM functional potential on d 21 than on d 0, while CAZy class abundances did not change over time in Control steers. Differential network analysis indicated a greater normalized degree for GT in the SCFP steers compared with Control on d 21. There were 2, 6 and 12 differently abundant species (P < 0.01) between SCFP and Control on d 0, 2 and 21, respectively, suggesting supplementing SCFP altered the abundances of more species over time. Our results showed that the postbiotic program altered the metabolic pathways of ruminal microbes toward greater propionate production, and improved abundance of carbohydrate binding modules. Our results also showed that glycosyl transferases had a greater promotive role in the ruminal enzymatic network of SCFP steers.

Milk Yields and Milk Fat Composition Promoted by Pantothenate and Thiamine via Stimulating Nutrient Digestion and Fatty Acid Synthesis in Dairy Cows.

Considering the synergistic effect of pantothenate and thiamine on the regulation of energy metabolism, this study investigated the influences of coated calcium pantothenate (CCP) and coated thiamine (CT) on milk production and composition, nutrients digestion, and expressions of genes involved in fatty acids synthesis in mammary glands. Forty-four multiparous Chinese Holstein cows (2.8 ± 0.19 of parity, 772 ± 12.3 kg of body weight [BW], 65.8 ± 8.6 days in milk [DIM] and 35.3 ± 1.9 kg/d of milk production, mean ± SD) were blocked by parity, BW, DIM, and milk production, and they were allocated into one of four treatments in a 2 × 2 factorial block design. Additional CCP (0 mg/kg [CCP-] or 55 mg/kg dry matter [DM] of calcium pantothenate from CCP [CCP+]) and CT (0 g/kg [CT-] or 5.3 mg/kg DM of thiamine from CT [CT+]) were hand-mixed into the top one-third of total mixed ration. Both CCP and CT additives increased milk production, fat content, true protein, and lactose by promoting nutrient digestibility. The CCP or/and CT supplementation induced the elevation of C11:0, C12:0, C13:0, C14:0, C14:1, C15:0, C15:1, C16:00, C16:1, C24:00, C24:1 fatty acids, saturated fatty acid, and C4-16 fatty acid contents in milk fat; but it decreased C17-22 fatty acid content. Ruminal total VFA content was increased, but pH was decreased by both additives. The ruminal fermentation pattern was altered, and a tendency of acetate formation was implied by the increased acetate-to-propionate ratio after both additives' supplementation. The expressions of PPARγ, SREBPF1, ACACA, FASN, SCD, and FABP3 mRNAs were enhanced by CCP or CT addition, but the relative expression of LPL mRNA was upregulated by CT addition only. Additionally, blood glucose, triglyceride, insulin-like growth factor-1, and total antioxidant capacity were promoted by both additives. The combination of CCP and CT more effectively increased the ruminal total VFA concentration, the acetate to propionate ratio, and blood glucose level, and decreased ammoniacal nitrogen concentration than that achieved by CCP or CT alone. The results suggested that CCP and CT supplementation stimulated lactation performance by promoting nutrient digestion and fatty acid synthesis in the mammary glands.

345 Evaluation of the Effects of Hempseed Cake on Ruminal Fermentation Parameters, Nutrient Digestibility, Nutrient Flow, and Nitrogen Balance in Finishing Steers

Abstract There is interest in feeding industrial hemp production byproducts to livestock, but little is known about the digestibility and ruminal fermentation parameters associated with this feedstuff. A nutrient balance experiment using crossbred steers (n = 5; initial BW = 542 kg, SD = 40 kg) in a Youden square design was conducted to evaluate the effects of feeding hempseed cake (HEMP) or dried corn distillers grains plus solubles [DDGS; each included at 20% of diet dry matter (DM) in respective treatments] in comparison with a dry-rolled corn-based negative control treatment (CON) on ruminal fermentation parameters, nutrient digestibility, nutrient flow and nitrogen (N) balance. Organic matter (OM) tended (P = 0.07) to increase and OM total tract apparent digestibility decreased (P = 0.03) in steers fed the HEMP diet compared with steers fed the DDGS and CON diets. Total tract apparent N digestibility was greatest (P < 0.01) in steers fed the HEMP diet, while total tract apparent digestibility in all other nutrients was not influenced (P ≥ 0.13) by treatment. Furthermore, apparent ruminal digestibility of OM was greatest (P < 0.01) in steers fed the HEMP or CON diets, and neutral detergent fiber, acid detergent fiber (ADF), and true ruminal digestibility of N was greatest (P ≤ 0.04) in steers fed the HEMP diet. Ruminal total amino acid degradation and total ruminal VFA concentration was greatest (P < 0.01) in steers fed the HEMP diet. A treatment by hour interaction (P = 0.01) was observed for ruminal ammonia concentration. Nitrogen retention was greatest (P < 0.01) in steers fed the HEMP diet, suggesting that feeding hempseed cake improved utilization of N. These results suggest that although ruminal digestibility of all nutrients is greater in steers fed the HEMP diet, greater ADF concentration in hempseed cake negatively influences total tract apparent OM digestibility when fed to finishing steers.

Effects of adding live Saccharomyces cerevisiae and Aspergillus-based enzyme extracts on ruminal fermentation, plasma polyamine concentrations, and fiber digestibility in beef steers fed a high-forage diet

We evaluated the effects of adding live Saccharomyces cerevisiae (SC) and Aspergillus -based extract (ABE) on rumen fermentation, plasma polyamine concentrations, and in vitro fiber digestibility in beef steers fed mixed red clover–orchardgrass hay. Eight rumen-cannulated Angus crossbred beef steers were assigned to 4 treatments arranged in a replicated 4 × 4 Latin square design with four 21-d periods. Dietary treatments were (1) control (CON; basal diet without additive), (2) SC (CON + 15 g/d of live SC), (3) ABE (5 g of ABE), and (4) SC+ABE (15 g/d of live SC + 5 g of ABE). On d 21, blood samples were collected before morning feeding for plasma metabolome analysis (including polyamines such as spermines, spermidine, and putrescine). Rumen fluid samples were collected 3, 6, and 9 h after feeding for analysis of VFA, ammonia-N concentrations, and in vitro DM and NDF digestibility. Compared with CON, neither SC nor ABE had effects ( P > 0.10) on rumen fermentation and in vitro digestibility. In contrast, SC+ABE increased ( P ≤ 0.05) the ruminal concentrations of acetate, butyrate, and total VFA and in vitro DM and NDF digestibilities. Both SC and SC+ABE increased ( P < 0.05) plasma concentrations of spermidine, spermine, and kynurenine. Supplementation of SC with or without ABE to forage-fed beef steers increased plasma concentrations of polyamines and kynurenine, a possible indication of improved immune function; however, combining SC and ABE, but not SC alone, improved the rumen fermentation and in vitro fiber digestibility.

Effects of cold temperature and fat supplementation on growth performance and rumen and blood parameters in early fattening stage of Korean cattle steers

We investigated the effects of cold ambient temperatures and the supplementation of rumen-protected fat (RPF) on the growth performance, rumen fermentation parameters, and blood metabolic parameters of Korean cattle steers during the early fattening stage. Twenty Korean cattle steers (body weight = 356.5 ± 3.72 kg, age = 16.8 ± 0.34 months) were divided into two groups: 10 steers were fed a conventional concentrate (control), and 10 steers were fed a concentrate supplemented with 8 g/kg RPF (treatment). Steers were fed a concentrate at 1.6% body weight and 3 kg tall fescue hay daily for 12 weeks in 2016: January 8 to February 2 (P1), February 3 to March 3 (P2), and March 4 to April 1 (P3). Body weight was measured, and blood and rumen fluid were collected four times from each steer: at the start of the experiment, and then at 4-week intervals. The mean indoor temperatures during P1 (−7.37 ℃) and P2 (–2.96℃) were lower (P < 0.001) than the mean P3 temperature (6.22 ℃). These lower temperatures were within the range that causes mild to moderate cold stress (CS) in other cattle breeds. By contrast, the mean indoor temperature during P3 is considered thermoneutral. The average daily gain (P = 0.39 and P = 0.16) and gain-to-feed ratio (P = 0.26 and P = 0.57) were not affected by RPF supplementation or time-period. Total dry matter, crude protein, ether extract, neutral detergent fiber, and acid detergent fiber intakes per body weight were higher (all P < 0.001) in colder P1 or P2 compared to other time periods, but these variables were not affected (P ≥ 0.31) by RPF supplementation, except ether extract intake. Ruminal total VFA concentrations were higher (P = 0.001) in a colder January than in other months, but these were not affected (P = 0.26) by RPF supplementation. The ruminal propionate proportion was higher (P < 0.001) in a colder January than in other months, whereas the butyrate proportion was lower (P = 0.01). Serum triglyceride (P = 0.007), total cholesterol (P = 0.001), and high-density lipoprotein (P = 0.03) concentrations were lower during colder months. RPF supplementation increased (P = 0.008) serum cholesterol concentrations. Our results indicate that mild to moderate CS may not affect Korean cattle, as cattle growth performance was not affected by colder temperatures, although concentrate and forage intakes were increased, and some changes in blood metabolic and ruminal parameters were observed. The 8 g/kg RPF supplementation did not improve growth performance under cold conditions, although it did not decrease intake and ruminal total VFA concentration.

Effects of feeding mother liquor, by-product of monosodium glutamate, on digestibility, energy and nitrogen balances, and rumen condition in Thai native bulls.

Four Thai native bulls were used to evaluate the availability of mother liquor (ML), by-product of monosodium glutamate, as a replacement of soybean meal (SBM) consisting of 10% in concentrate. The SBM was replaced by the ML at 0% (C), 20% (T1), 40% (T2), and 60% (T3), and the experiment was a randomized block design experiment. The animals were fed concentrate and roughage (60:40, on a dry matter [DM] basis). There were no significant differences in the digestibility of DM, crude protein, ether extract, acid detergent fiber expressed exclusive of residual ash and non-fibrous carbohydrate, and energy and nitrogen balances among the treatments. However, the digestibility of the neutral detergent fiber in T2 was lower than the other treatments (p<.05). The valeric acid of T2 was lower than those of C and T1 and the iso-valeric acid of T3 was the lowest (p<.05), followed by those of T2, T1, and C at 4hr post-feeding. No significant differences were observed in the ruminal total VFA concentrations, pH, and NH3 -N among the treatments. These results suggested that SBM could be replaced by the ML up to 60% without adverse effects on nitrogen and energy balance, rumen conditions, and blood metabolites in Thai native bulls.

Polyherbal feed additive for lambs: effects on performance, blood biochemistry and biometry

ABSTRACT An experiment was conducted to evaluate the effect of a polyherbal mixture based on Withania somnifera, Ocimum tenuiflorum, Tinospora cordifolia and Emblica officinalis, on lamb’s growth and blood metabolites. Thirty-two lambs (initial body weight BW 25 ± 4.1 kg) were randomly assigned to the treatments which consisted of the polyherbal ImmuPlus at dietary concentrations of 0, 0.1, 0.2 and 0.3% of dry matter (DM) for 60 days. There was a quadratic response to polyherbal in average daily gain (p < 0.01) and feed conversion (p < 0.05). The optimal concentration estimated by regression for maximum ADG was 0.14 ± 0.08% DM of ImmuPlus. Ruminal DM digestibility was not affected but pH was reduced linearly (p < 0.05). Ruminal N-NH3 (p < 0.01) and total VFA concentration showed a quadratic increment (p < 0.05) whereas butyrate proportion was increased linearly (p < 0.05). There was no effect in most blood metabolites related to energy metabolism, but uric acid was linearly reduced (p < 0.01) and bilirubin showed a quadratic decrement (p < 0.05). Mean corpuscular haemoglobin (p < 0.01) increased linearly (p < 0.10), lymphocytes and segmented neutrophils showed a quadratic response (p < 0.01) and platelets showed a linear reduction (linear p < 0.05). The inclusion of ImmuPlus improved the daily gain in finishing lambs and feed efficiency at 0.1% DM without altering blood chemistry and blood biometry.

PSXIV-24 Immune function and growth performance in beef calves supplemented during backgrounding with live yeast and yeast cell wall in combination with supplemented dams

Abstract Live yeast and yeast cell wall products potentially improve health and performance in cattle during the stocker and feedlot phases. Therefore, the objective of this study was to investigate yeast-product supplementation during late gestation through 88 d of age, and(or) a 42-d backgrounding period on immune function and growth performance. Late gestation cows (n = 97) were assigned randomly to treatment: 1) supplement without yeast (CON) or 2) supplement with yeast products (YP). At weaning, calves from each dam treatment (CON or YP) were pooled by dam treatment and stratified based on BW, sex, dam parity, and sire and split into 8 pens within dam treatment. Pens were assigned randomly to 1 of 2 backgrounding treatments (CON or YP) such that a total of 4 pens/treatment existed. Treatments included: 1) dam YP, calf YP, 2) dam YP, calf CON, 3) dam CON, calf YP, and 4) dam CON, calf CON. Calves were fed 2 kg/d of grain and yeast (5 g/d) was provided in a top-dress (ground corn plus YP). Weaning weights (P = 0.99) and backgrounding ADG (P = 0.29) did not differ. Total ruminal VFA concentrations, sampled on d 0 and 42 post-weaning, were increased in calves from dams supplemented with YP (P = 0.04). There were no effects of treatment (P ≥ 0.32) on molar proportions of acetate and propionate. Haptoglobin (P ≥ 0.49) and neutrophil:lymphocyte ratio (P ≥ 0.46) were not influenced by treatment but were affected by day (P &amp;lt; 0.01). While there was no effect of YP (P = 0.73) on BVD titers, there was a day effect (P &amp;lt; 0.01) where titers were greatest on d 28 and least on d 0. Post-weaning yeast supplementation in combination with dam supplementation did not improve calf immune function or performance during a 42-d backgrounding period.

Effects of Lactic Acid Bacteria Inoculant on Fermentation Quality and &lt;i&gt;in vitro&lt;/i&gt; Rumen Fermentation of Total Mixed Ration

Fermented total mixed ration (TMR) is a novel feed for ruminants in South Korea. The purpose of this study was to evaluate the effects of lactic acid bacteria (LAB) on the quality of TMR and in vitro ruminal fermentation. Strains of three LAB spp. (Lactobacillus plantarum, L. brevis, L. mucosae) were used in fermentation of TMR. Inoculations with the three LAB spp. lowered pH and increased concentrations of lactic acid, acetic acid, and total organic acid compared to non-LAB inoculated control (only addition of an equivalent amount of water) (p<0.05). Bacterial composition indicated that aerobic bacteria and LAB were higher. However, E. coli were lower in the fermented TMR than those in the control treatment (p<0.05). Among the treatments, L. brevis treatment had the highest concentration of total organic acid without fungus detection. Gas production, pH, and ammonia-nitrogen during ruminal in vitro incubation did not differ throughout incubation. However, ruminal total VFA concentration was higher (p<0.05) in the LAB spp. treatments than the control treatment at 48 hours. Overall, the use of L. brevis as an inoculant for fermentation of high moisture. TMR could inhibit fungi growth and promote lactic fermentation, and enhance digestion in the rumen.

Effects of postbiotic supplementation on growth performance, ruminal fermentation and microbial profile, blood metabolite and GHR, IGF-1 and MCT-1 gene expression in post-weaning lambs

BackgroundPostbiotics have been established as potential feed additive to be used in monogastric such as poultry and swine to enhance health and growth performance. However, information on the postbiotics as feed additive in ruminants is very limited. The aim of this study was to elucidate the effects of supplementation of postbiotics in newly-weaned lambs on growth performance, digestibility, rumen fermentation characteristics and microbial population, blood metabolite and expression of genes related to growth and volatile fatty acid transport across the rumen epithelium.ResultsPostbiotic supplementation increased weight gain, feed intake, nutrient intake and nutrient digestibility of the lambs. No effect on ruminal pH and total VFA, whereas butyrate and ruminal ammonia-N concentration were improved. The lambs fed with postbiotics had higher blood total protein, urea nitrogen and glucose. However, no difference was observed in blood triglycerides and cholesterol levels. Postbiotics increased the population of fibre degrading bacteria but decreased total protozoa and methanogens in rumen. Postbiotics increased the mRNA expression of hepatic IGF-1 and ruminal MCT-1.ConclusionsThe inclusion of postbiotics from L. plantarum RG14 in newly-weaned lambs improved growth performance, nutrient intake and nutrient digestibility reflected from better rumen fermentation and microbial parameters, blood metabolites and upregulation of growth and nutrient intake genes in the post-weaning lambs.

Ruminal fermentation characteristics of goats selectively bred to have greater consumption of juniper foliage

The objective of this study was to determine if ruminal fermentation characteristics differed in goat lines selectively bred for high or low consumption of J. pinchotii foliage. Ten Boer × Spanish-composite bucks (age = 2 yr; initial body weight (BW) = 67.2 ± 4.3 kg) previously selected for high (High; n = 5) or low (LOW; n = 5) juniper consumption selected from each line were subjected to three periods: Period 1, d 0, grazing native range predominated by Juniperus spp; Period 2, d 1 to 26, group fed for ad libitum intake of sorghum × sudan hay; and Period 3, d 27 to 63, indivually fed sorghum × sudan hay at 3% of body weight (BW) and offered fresh J. pinchotii foliage for ad libitum intake. During each period, rumen fluid was evaluated for pH, VFA, ammonia N (NH3-N), and juniper foliage was evaluated for 48-hr true IVDMD (tIVDMD). There was a Selection line × Period interaction observed for total VFA (P < 0.01) explained by a reranking of Total VFA observed in HIGH compared to LOW selection lines in Periods 1 and 3, but the effect was reversed in Period 2. However, total VFA did not differ within any period between HIGH and LOW. During Period 1, rumen fluid from HIGH contained greater (P < 0.05) ruminal isovalerate and tended to have greater ruminal isobutyrate (P = 0.09) and NH3-N (P = 0.07) than LOW. There was a period effect (P < 0.02) for all response variables. When transitioned to a sorghum × sudan hay diet (Period 2), total ruminal VFA concentrations declined 26 and 4% for HIGH and LOW, respectively, and total VFA (P = 0.08) and valerate (P = 0.09) tended to be greater for LOW compared with HIGH. In vitro digestibility of juniper did not differ (P ≥ 0.48), but numerically, digestibility declined 13 and 12% for HIGH and LOW, respectively, from Period 1 to 2. During Period 3, when transitioned to individual pens with ad libitum access to sorghum × sudan hay and juniper foliage, juniper intake did not differ (P = 0.16) with HIGH consuming 1.2 g/kg BW of juniper compared with 0.62 g/kg BW for LOW. No differences were detected (P > 0.05) for VFA, NH3-N, pH, and tIVDMD between HIGH and LOW goats during Period 3. Goats selectively bred for high or low juniper consumption exhibited minor differences in rumen fermentation parameters measured in the current study.

Genetic parameters of plasma and ruminal volatile fatty acids in sheep fed alfalfa pellets and genetic correlations with enteric methane emissions1.

Animal-to-animal variation in methane (CH4) emissions determined in respiration chambers has a genetic basis, but rapid phenotyping methods that can be applied on-farm are required to enable increased genetic progress by the farming industry. Fermentation of carbohydrates in the rumen results in the formation of VFA with hydrogen (H2) as a byproduct that is used for CH4 formation. Generally, fermentation pathways leading to acetate are associated with the most H2 production, less H2 formation is associated with butyrate production, and propionate and valerate production are associated with reduced H2 production. Therefore, VFA may constitute a potential correlated proxy for CH4 emissions to enable high-throughput animal screening. The objective of the present study was to determine the genetic parameters for ruminal and plasma VFA concentrations in sheep fed alfalfa (Medicago sativa L.) pellets and their genetic (rg) and phenotypic (rp) correlations with CH4 emissions. Measurements of CH4 emissions in respiration chambers and ruminal (stomach tubing 18 h from last meal) and blood plasma (3 h post-feeding) VFA concentrations were made on 1,538 lambs from 5 birth years (2007 and 2009 to 2012) aged between 5 and 10 mo, while the animals were fed alfalfa pellets at 2.0 times maintenance requirements in 2 equal size meals (0900 and 1500 h). These measurements were repeated twice (rounds) 14 d apart. Mean (± SD) CH4 production was 24.4 ± 3.08 g/d, and the mean CH4 yield was 15.8 ± 1.51 g/kg DMI. Mean concentration of total ruminal VFA was 52.2 mM, with concentrations of acetate, propionate and butyrate of 35.97, 8.83, and 4.02 mM, respectively. Ruminal total VFA concentration had heritability (h2) and repeatability estimates (± SE) of 0.24 ± 0.05 and 0.35 ± 0.03, respectively, and similar estimates were found for acetate, propionate, and butyrate. Blood plasma concentrations of VFA had much lower estimates of h2 and repeatability than ruminal VFA. Genetic correlations with CH4 yield were greatest for total concentrations of ruminal VFA and acetate, with 0.54 ± 0.12 and 0.56 ± 0.12, respectively, which were much greater than their corresponding rp. The rp and rg of ruminal VFA proportions and blood VFAs with CH4 emissions were in general lower than for ruminal VFA concentrations. However, minor ruminal VFA proportions had also moderate rg with CH4 yield. Pre-feeding concentrations of total VFA and acetate were the strongest correlated proxies to select sheep that are genetically low CH4 emitters.

Effects of dietary soybean oil and coated folic acid on ruminal digestion kinetics, fermentation, microbial enzyme activity and bacterial abundance in Jinnan beef steers

This study was conducted to evaluate the effects of dietary soybean oil (SO) and coated folic acid (CFA) supplementation on ruminal digestion kinetics, fermentation, microbial enzyme activity and bacterial abundance in Jinnan beef steers. Eight ruminally cannulated Jinnan beef steers, averaging 15 months of age and 415 ± 5.6 kg of body weight (BW; Mean ± S.E.), were used in a replicated 4 × 4 Latin square design by a 2 × 2 factorial arrangement. Two levels of CFA (0 mg [FA-] or 115 mg per kg dietary DM [FA + ]) were supplemented to the diets without or with SO supplementation (0 g [SO−] or 30 g per kg dietary dry matter [DM] [SO + ]). Steers were fed a total mixed ration with ensiled corn forage to concentrate ratio of 50:50 on a DM basis. The SO × CFA interaction was observed for ruminal pH, total VFA concentration, molar proportions of acetate and propionate, the ratio of acetate to propionate and ammonia N content. Ruminal pH increased with SO supplementation, but decreased with CFA supplementation. Ruminal total VFA concentration, acetate molar proportion and acetate to propionate ratio decreased with SO supplementation, but increased with CFA supplementation. Ruminal ammonia-N content decreased with SO or CFA supplementation. No SO × CFA interaction was observed for nutrient degradability and digestibility. Degradability of neutral detergent fibre (NDF) and digestibility of DM, organic matter, NDF and acid detergent fibre decreased with SO supplementation, but increased with CFA supplementation. Degradability and digestibility of crude protein was not affected by SO supplementation, but increased with CFA supplementation. Pectinase activity was unaltered, whereas, other microbial enzyme activity, bacterial abundance and total PD excretion were affected by SO × CFA interaction. Activities of carboxymethyl-cellulase, cellobiase and xylanase and abundance of R. albus, R. flavefaciens, F. succinogenes and B. fibrisolvens decreased with SO supplementation, but increased with CFA supplementation. Activities of pectinase, α-amylase and protease as well as total bacterial abundance were not affected by SO supplementation, but increased with CFA supplementation. Total protozoal abundance decreased with SO supplementation, but was not affected by CFA supplementation. Abundance of P. ruminicola and R. amylophilus increased with SO or CFA supplementation. Total PD excretion increased with CFA supplementation, but decreased with SO supplementation. The results suggested that ruminal fermentation, NDF degradability, protozoal abundance, cellulolytic bacterial abundance and enzyme activity decreased with dietary SO supplementation, but increased with CFA supplementation. The supplementation of CFA in the SO diet could relieve the negative effects of SO on ruminal fermentation.

Investigating ruminant digestive characteristics of finishing beef steers fed sorghum wet distillers grains treated with calcium hydroxide

<h2>ABSTRACT</h2> Alkali treatment has been used to increase the digestibility of low-quality, fibrous crop residues. However, alkali treatment of the fiber fraction in distillers grains has only briefly been explored. Six ruminally cannulated steers (444 ± 4.0 kg of BW) were used to evaluate the effects of treating sorghum wet distillers grains plus solubles (SWDGS) with calcium hydroxide (CH) in finishing diets. Treatment diets were based on steam-flaked corn and included (1) 30% corn wet distillers grains plus solubles (CDG), (2) 30% SWDGS (SDG), or (3) 30% SWDGS treated with 2.27% CH (SDG-CH). Data were analyzed as a replicated Latin square with 3 dietary treatments and 3 periods using the MIXED procedure of SAS with animal within square as the experimental unit. No differences (<i>P</i> = 0.47) in DMI were observed. Steers consuming CDG had the greatest (<i>P</i> < 0.01) total ruminal VFA concentration, followed by SDG-CH, with SDG having the least. Steers consuming SDG had the greatest (<i>P</i> < 0.01) ruminal pH, followed by SDG-CH and then by CDG. Steers consuming SDG had the greatest (<i>P</i> < 0.01) ruminal acetate:propionate ratio, followed by SDG-CH, with CDG having the least. Steers consuming SDG-CH tended (<i>P</i> = 0.07) to have a greater apparent total-tract digestibility of NDF. No differences (<i>P</i> ≥ 0.15) were observed in apparent total-tract digestibility of DM, OM, ADF, starch, or N. Treating SWDGS with CH increased the digestibility of fiber compared with untreated SWDGS in finishing diets.

Dietary supplements during the cold season increase rumen microbial abundance and improve rumen epithelium development in Tibetan sheep.

Livestock on the Qinghai-Tibetan Plateau are faced with extreme harsh winters and are often in negative energy balance during this period. Dietary supplementation can improve growth performance of Tibetan sheep and, consequently, we hypothesized that it would also increase microbial abundance and rumen epithelium development. To test this hypothesis, we examined the effect of feed supplementation during the cold season on rumen microbes, fermentation, epithelium development, and absorptive capability in Tibetan sheep. Eighteen 1-yr-old ewes (BW = 29.4 ± 1.79, kg) were offered oat hay ad libitum for 60 d and divided randomly into three groups: 1) no supplement; control group (CON); 2) urea-molasses lick block supplement (BS); and 3) concentrate feed supplement (CS). The ADG of CS ewes (143.3, g/d) was greater (P < 0.05) than BS ewes (87.9, g/d), which was greater (P < 0.05) than CON ewes (44.5, g/d). Serum concentrations of GH, IGF-1, and IGF-2 in the CS and BS groups were greater than in the CON group (P < 0.05). Greater relative abundance of protozoa, Ruminococcus albus, Fibrobacter succinogenes, Streptococcus bovis, and Ruminobacter amylophilus was observed in the CS and BS groups than in the CON group (P < 0.05), and relative abundances of rumen fungi, Butyrivibrio fibrisolvens, and Prevotella ruminicola in the CS group were greater than in the BS and CON groups (P < 0.05). Ruminal total VFA, ammonia, and microbial protein concentrations in the CS and BS groups were greater than in the CON group (P < 0.05), and in the CS group were greater than in the BS group (P < 0.05). Ruminal papillae width and surface area in the CS and BS groups were greater than in the CON group (P < 0.05), while in the CS group were greater than in the BS group (P < 0.05). The mRNA expressions of IGFBP5, NHE1 (sodium/hydrogen antiporter, isoform 1), DRA (downregulated in adenoma), and Na+/K+-ATPase (sodium/potassium ATPase pump) in ruminal epithelium were greater in the CS and BS groups than in the CON group (P < 0.05), and in the CS group was greater than in the BS group (P < 0.05), while NHE3 (sodium/hydrogen antiporter, isoform 3), MCT1 (monocarboxylate transporter 1), and MCT4 (monocarboxylate transporter 4) mRNA expressions in the CS group were greater than in the BS and CON groups (P < 0.05). It was concluded that supplementing Tibetan sheep during the cold season increases rumen microbial abundance and improves fermentation parameters, rumen epithelium development, and absorptive capability.

Response of rumen bacterial diversity and fermentation parameters in beef cattle to diets containing supplemental daidzein

An experiment was conducted to determine the effects of soy isoflavone daidzein on ruminal fermentation, microbial protein synthesis and rumen bacterial community in beef cattle. Six rumen-cannulated adult beef cattle were assigned to three blocks according to similar body weight in a randomised block design, with two cattle each block. Each block randomly received one of the two dietary treatments: control (basal concentrate) and daidzein (supplementation with 500 mg daidzein/kg basal concentrate). High-throughput sequencing data showed that supplemental daidzein increased the relative abundance of bacteria belonging to phylum Bacteroidetes (p = .050), but reduced and tended to reduce the relative abundance of phylum Spirochaetae (p = .030) and Firmicutes (p = .080). At the genus level, the relative abundance of Prevotella (p = .036), RC9_gut_group (p = .019), Succinivibrio (p = .093) and Ruminobacter (p = .085) were increased or tended to be increased by daidzein supplementation. However, supplemental daidzein reduced or tended to reduce some uncultured and unclassified bacteria genus belonging to Ruminococcaceae (p = .028), Prevotellaceae (p = .088) and Lachnospiraceae (p = .068). The ruminal pH (p = .023) and ammonia-N (p = .031) concentration were lower in the daidzein group than in the control group, but the daidzein group tended to have greater ruminal total VFA (p = .063) concentration. Supplemental daidzein increased urinary excretion of allantoin (p = .005) and total purine derivatives (p = .007). Current results suggest that supplemental daidzein can affect ruminal fermentation by changing ruminal microbial community, increase the production of VFA and enhance microbial protein synthesis in the rumen, showing the potential of daidzein for improving ruminal fermentation in beef cattle.

Effects of dietary protein levels and 2-methylbutyrate on ruminal fermentation, nutrient degradability, bacterial populations and urinary purine derivatives in Simmental steers.

The objective of this study was to evaluate the effects of dietary crude protein (CP) levels and 2-methylbutyrate (MB) supplementation on ruminal fermentation, bacterial populations, microbial enzyme activity and urinary excretion of purine derivatives (PD) in Simmental steers. Eight ruminally cannulated Simmental steers, averaging 18months of age and 465±8.6kg of body weight (BW), were used in a replicated 4×4 Latin square design by a 2×2 factorial arrangement. Low protein (98.5g CP/kg dry matter [LP] or high protein (128.7g CP/kg dry matter [HP]) diets were fed with MB supplementation (0g [MB-] or 16.8gsteer-1 day-1 [MB+]). Steers were fed a total mixed ration with dietary corn straw to concentrate ratio of 50:50 (dry matter [DM] basis). The CP×MB interaction was observed for ruminal total VFA, molar proportions of acetate and propionate, acetate to propionate ratio, ammonia-N, effective degradability of neutral detergent fibre (NDF) and CP, microbial enzyme activity, bacterial populations and total PD excretion (p<.05). Ruminal pH decreased (p<.05), but ruminal total VFA concentration increased (p<.05) with increasing dietary CP level or MB supplementation. Acetate molar proportion increased (p=.043) with MB supplementation, but was not affected by dietary CP level. Propionate molar proportion decreased (p<.05) with increasing dietary CP level or MB supplementation. Consequently, acetate-to-propionate ratio increased (p=.001) with MB supplementation, but was not affected by dietary CP level. Ruminal ammonia-N content increased (p=.034) with increasing dietary CP level, but decreased (p=.012) with MB supplementation. The effective degradability of NDF and CP increased (p<.05) with increasing dietary CP level or MB supplementation. Microbial enzyme activity, bacterial populations and total PD excretion also increased (p<.05) with increasing dietary CP level or MB supplementation. The results indicated that ruminal fermentation, nutrient degradability, microbial enzyme activity, ruminal bacterial populations and microbial protein synthesis improved with increasing dietary CP level or MB supplementation in steers.

Effects of dietary protein levels and rumen-protected pantothenate on ruminal fermentation, microbial enzyme activity and bacteria population in Blonde d'Aquitaine × Simmental beef steers

This study was undertaken to investigate the effects of dietary crude protein (CP) levels and rumen-protected pantothenate (RPP) supplementation on ruminal digestion kinetics, fermentation, microbial enzymatic activity, and selected bacterial species relative abundance in beef steers. Eight ruminally cannulated crossbred beef steers, with 15 months of age and 462±9kg of body weight (BW), were used in a duplicated 4×4 Latin square design by a 2×2 factorial arrangement. Low protein (113.7g/kg of CP [LP] or high protein (133.9g/kg of CP [HP]) diets were fed with or without RPP supplementation (0g [RP-] or 0.48g per kg dietary dry matter (DM) [RP+]). Steers were fed a total mixed ration containing dietary concentrate to corn silage ratio of 50:50 on a DM basis. There were no RPP×CP interactions for ruminal digestion kinetics, fermentation, microbial enzymatic activity, and selected bacterial species relative abundance, except for Ruminobacter amylophilus. Mean ruminal pH decreased with RPP supplementation, but was unaffected by dietary CP levels. Ruminal total VFA concentration increased with increasing dietary CP levels or RPP supplementation. Ruminal acetate percentage was similar among treatments, whereas propionate percentage decreased with increasing dietary CP levels or RPP supplementation. Consequently, the acetate to propionate ratio increased with increasing dietary CP levels or RPP supplementation. Ruminal ammonia-N content was unchanged among treatments. Both in situ ruminal DM degradability of corn silage and CP degradability of concentrate increased with RPP supplementation and tended to increase with increasing dietary CP levels, while NDF degradability of corn silage and DM degradability of concentrate increased with increasing dietary CP levels or RPP supplementation. Activities of carboxymethyl-cellulase, cellobiase, xylanase, pectinase, α-amylase and protease, populations of Ruminococcus albus, Ruminococcus flavefaciens, Butyrivibrio fibrisolvens and Prevotella ruminicola, and urinary excretion of purine derivatives increased with increasing dietary CP levels or RPP supplementation, but populations of Fibrobacter succinogenes and R. amylophilus increased with RPP supplementation, and decreased with increasing dietary CP levels. The results showed that increasing dietary CP levels from 113.7g to 133.9g or with 0.48g RPP supplementation improved ruminal fermentation and microbial protein synthesis by increasing microbial populations and enzymes activities.

Effects of dried distiller's grains and lasalocid inclusion on feedlot lamb growth, carcass traits, nutrient digestibility, ruminal fluid volatile fatty acid concentrations, and ruminal hydrogen sulfide concentration.

Our hypothesis was that increasing the inclusion level of dried distiller's grains with solubles (DDGS) to feedlot lambs would increase growth and the inclusion of lasalocid (LAS; Bovatec, Alpharma, LLC, Bridgewater, NJ) would increase ADG and G:F, while not affecting digestibility, ruminal VFA concentration, and ruminal pH. Furthermore, we hypothesized that rations containing LAS and higher levels of DDGS would cause increased ruminal hydrogen sulfide gas (HS) concentrations. Two hundred forty crossbred (Suffolk × Rambouillet) lambs (31.9 ± 5.87 kg BW; approximately 90 d of age) were allocated to 6 treatments in a completely randomized design with a 3 × 2 factorial arrangement of treatments. Lambs were placed into 24 feedlot pens (4 pens/treatment; 10 lambs/pen) for a 111 d finishing study. Main effects included concentration of DDGS (0, 15, or 30% DM basis) and inclusion of LAS (0 or 22.05 g/metric ton LAS) resulting in treatments of: 1) 0% DDGS without LAS (0DDGS-NL), 2) 0% DDGS with LAS (0DDGS-L), 3) 15% DDGS without LAS (15DDGS-NL), 4) 15% DDGS with LAS (15DDGS-L), 5) 30% DDGS without LAS (30DDGS-NL), and 6) 30% DDGS with LAS (30DDGS-L). Two-day weights were taken at the beginning and end of the experiment. Two-hundred-eighteen lambs (64.8 ± 7.99 kg BW) were slaughtered on d 112 at a commercial abattoir and carcass data collected. The inclusion of LAS increased ( ≤ 0.02) final BW, ADG, G:F, and HCW. As DDGS in the ration increased to 30%, DMI decreased linearly ( = 0.03) while G:F increased linearly ( = 0.03). A second study was conducted utilizing the same treatments to evaluate N and S balance, ruminal VFA and H2S concentration, and ruminal pH in 24 crossbred wethers (Suffolk × Rambouillet; 41.2 ± 12.23 kg BW). Daily urinary sulfur excretion and ruminal H2S concentration were linearly increased ( < 0.001) as DDGS increased in the ration. Total ruminal VFA concentration linearly decreased ( = 0.002) as DDGS increased in the ration. The inclusion of LAS increased ( = 0.02) ruminal pH. The results confirm our hypothesis that LAS increased overall growth and increasing DDGS increased ruminal HS concentration but did not influence growth. We reject the hypothesis that the combined effects of LAS and DDGS would have no effect on rumen pH and VFA concentrations.