We evaluated the effects of neutral detergent soluble fiber （NDSF） and sucrose supplementation on ruminal fermentation, microbial synthesis, and populations of ruminal cellulolytic bacteria using the rumen simulatio...We evaluated the effects of neutral detergent soluble fiber （NDSF） and sucrose supplementation on ruminal fermentation, microbial synthesis, and populations of ruminal cellulolytic bacteria using the rumen simulation technique （RUSITEC）. The experiment had a 2x2 factorial design with two dosages of sucrose, low （ca. 0.26 g d-1, low-sucrose） and high （ca. 1.01 g d-1, high-sucrose）, and two dosages of supplied NDSF, low （1.95 g d-1, Iow-NDSF） and high （2.70 g d-1, high-NDSF）. Interactions between NDSF and sucrose were detected for xylanase activity from solid fraction and apparent disappearance of neutral detergent fiber （NDF） and hemicellulose, with the lowest values observed for high-NDSF and high-sucrose treatment. Supplemental NDSF appeared to increase the molar proportion of acetate and reduce that of butyrate; however, the effects of supplemental sucrose on VFA profiles depended upon NDSF amount. There was a NDSFxsucrose interaction for the production of methane. High-NDSF fermenters had lower ammonia-N production, greater daily N flow of solid- associated microbial pellets and total microorganisms, and greater microbial synthesis efficiency compared with low- NDSF fermenters. Supplementation with NDSF resulted in an increase in 16S rDNA copies of Ruminococcusflavefaciens and a reduction in copies of Ruminococcus albus. Supplementation with sucrose tended to increase the 16S rDNA copies ofR. albus from liquid fraction, but did not affect daily total microbial N flow and cellulolytic bacterium populations from solid fraction. These data indicate that the effects of the interaction between NDSF and sugars on ruminal fermentation and fiber digestion should be taken into account in diet formulation. Ruminal fermentation and metabolism of sugars warrant further investigation.展开更多
Twenty-eight male, weaned Chinese Holstein calves（（156.8±33.4） kg） were used to investigate the effects of dietary forage to concentrate ratio（F：C） and forage length on nutrient digestibility, plasma metab...Twenty-eight male, weaned Chinese Holstein calves（（156.8±33.4） kg） were used to investigate the effects of dietary forage to concentrate ratio（F：C） and forage length on nutrient digestibility, plasma metabolites, ruminal fermentation, and fecal microflora. Animals were randomly allocated to four treatments in a 2×2 factorial arrangement： whole-length forage（WL） with low F：C（50：50）; WL with high F：C（65：35）; short-length forage（SL） with high F：C（65：35）; and SL with low F：C（50：50）. Chinese wildrye was used as the only forage source in this trial. The grass in the SL treatments was chopped using a chaff cutter to achieve small particle size（-50% particles 〉19 mm）. Dry matter intake（DMI） and organic matter（OM） intake was increased by increasing both F：C（P〈0.01） and forage length（FL）（P〈0.05）, while acid detergent fiber（ADF） and neutral detergent fiber（NDF） intakes were only increased by increasing the F：C（P〈0.01）. The digestibility of NDF was increased as the FL increased（P〈0.01）, and it was also affected by interaction between F：C and FL（P〈0.05）. Cholesterol（CHO）（P〈0.01）, leptin（LP）（P〈0.05）, and growth hormone（GH）（P〈0.01） concentrations in plasma were increased as dietary F：C increased. A significant increase in plasma triglyceride（TG）（P〈0.01）, insulin（INS）（P〈0.05）, and GH（P〈0.01） levels was observed with decreasing dietary FL. Ruminal p H values of calves fed with low F：C diets were significantly lower than those in high F：C treatment（P〈0.05）. Increasing the F：C enhanced ruminal acetic acid（P〈0.05） and acetic acid/propionic acid（P〈0.01）. Fecal Lactobacillus content was significantly higher, while Escherichia coli and Salmonella contents were significantly lower in WL and high F：C groups（P〈0.05）. Lower fecal scores（higher diarrhea rate） were observed in calves fed with SL hay compared to WL hay（P〈0.05）. Denatured gradient gel electrophoresis（DGGE） bands and richness index（S） were significantly affected by the interaction between F：C and FL（P〈0.05）, under high F：C, band numbers and richness index from WL group were higher than that from SL group（P〈0.05）, whereas there were no differences between WL andSL groups under low F：C（P〉0.05）. Microflora similarity was 50–73% among the different treatments. It is concluded that the WL with high F：C（65：35） diet is suitable for weaned calves.展开更多
This study was conducted to investigate the effect of Soybean Peptides(SPs) on ruminal fermentation and microbial diversity in vitro. Four levels of SPs supplements(0, 0.25%, 0.50% and 0.75% dry matter basis) were tes...This study was conducted to investigate the effect of Soybean Peptides(SPs) on ruminal fermentation and microbial diversity in vitro. Four levels of SPs supplements(0, 0.25%, 0.50% and 0.75% dry matter basis) were tested. p H, NH3-N, Neutral Detergent Fiber(NDF), Acid Detergent Fiber(ADF), Dry Matter Digestibility(DMD) and the Total Volatile Fatty Acid(TVFA) were measured at 6, 24, 48 h of in vitro mixed incubation the fluids. Microbial populations were determined at 24 h and Microbial Proteins(MCP) were determined at 24 and 48 h. The gas production after 48 h in vitro incubation presented linear growth(p<0.05) and the highest content was the level of 0.5% SPs(dry matter basis). NH3-N concentration reached the highest concentration with 0.75%(dry matter basis) at 48 h. p H linearly increased(linear, p<0.05) from 6 to 48 h. The digestion of DMD increased with increasing doses of SPs at 24 h. NDF and ADF linearly(p<0.01) decreased by adding SPs. The concentration of TVFA linearly increased(p<0.05) at 6, 24 and 48 h, and reached the highest concentration at the level of 0.75%(dry matter basis). SPs decreased(p<0.05) the molar proportion of acetate and propionate, respectively at 24 and 48 h. Acetat to Propionate ratio(A/P; linear, p<0.05) increased at 48 h, and reached the greatest value at the level of 0.75%(dry matter basis) at 48 h. The populations of rumen Ruminococcus flavefaciens(R. flavefaciens), Ruminococcusalbus(R. albus), Fibrobacter succinogenes(F. succinogenes), Butyrivibrio fibrisolvens(B. fibrisolvens), Streptococcus bovis(S.bovis), Ruminobacter amylophilus(R. amylophilus) and Succinimonas amylolytica(S. amylolytica) were analyzed based on the total rumen bacterial 16 S ribosomal deoxyribonucleic acid(r DNA). The relative abundance of R. flavefaciens and R. albus increased at 24 h, but the relative abundance of F. succinogenes decreased at this time. The incubation of SPs had no effect on the abundance of S. bovis and R. amylophilus. The relative abundance of B. fibrisolvens and S. amylolytica reached the greatest value(p<0.05) at middle doses of SPs inclusion at 24 h. The value of MCPs linearly increased(p<0.05) at 24 and 48 h. These results showed that SPs could improve in vitro fermentation and nutrient digestion of feed substrates, and had the ability to modulate the ruminal fermentation pattern by regulating the composition of functional rumen microbes. Hence, SPs might be a potential feed additive applied in the diets of ruminants.展开更多
The effects of supplemental carbohydrate （CHO） sources on milk yield and composition, nitrogen （N） balance,and ruminal fermentation were evaluated in lactating dairy cows fed energy-deficient total mixed rations ...The effects of supplemental carbohydrate （CHO） sources on milk yield and composition, nitrogen （N） balance,and ruminal fermentation were evaluated in lactating dairy cows fed energy-deficient total mixed rations （TMR） . Fifty-six lactating Holstein cows （36. 8 ± 3. 4 kg / d of milk yield; 152 ± 26 days in milk [DIM]） were randomly assigned to one of four diets： （1） basal TMR （control） ; （2） basal TMR ＋ 1. 25 kg / d sucrose （SUC） ; （3） basal TMR ＋ 2. 12 kg /d steam-flaked corn （SFC） ; （4） basal TMR ＋ 2. 23 kg / d wheat （WHE） . The trial lasted 70 days,including the first 10 days of adaptation. Simultaneously, a 4 × 4 Latin square trial was conducted with four ruminally cannulated cows of similar DMI （Dry Matter Intake） fed on the above four diets. Each testing period lasted 18 days： 15 days for adaptation and 3 days for sampling. Cows fed SUC-,SFC-,and WHE-supplemented diets produced 1. 6,2. 9,and 0. 8 kg / d,respectively,more milk than those on the basal TMR control diet,but the difference was not significant （P = 0. 160） . However,the production of energy-corrected milk of cows fed CHO-supplemented diets improved significantly （P = 0. 020） ,and the yield of 4% fatcorrected milk tended to be higher （P = 0. 063） than in control animals. Percentages of milk protein,lactoseand solids-not-fat （SNF） increased significantly in cows fed CHO-supplemented diets （P 〈 0. 05） ,and yields of milk protein and SNF were significantly higher （P 〈0. 05） ; yields of milk fat and lactose were somewhat higher （P 〈 0. 10） . Cows receiving supplementary CHO diets consumed more DM （Dry Matter） （P = 0. 023） ; however,there was no significant difference in N retention,digestibility,or utilization efficiency among the treatments （P 〉 0. 10） . The average ruminal pH was lowest in cows supplemented with SUC,while that in cows supplemented with SFC and WHE was only slightly reduced （P = 0. 025） . Ruminal NH 3 -N concentration was highest with no supplementary CHO （P = 0. 017） ,and changes in postfeeding time were similar across the diets. Total volatile fatty acid concentration was significantly lower in control animals than in those on SUCand WHE-supplemented diets （P = 0. 001） ; significant dietary responses were observed in the concentrations of acetate,butyrate,and branchedchain fatty acids and in the acetate-to-propionate ratio （P 〈0. 001） . These results indicate that supplementation with different CHO sources in energy-deficient diets substantially improved the balance of energy and N in the rumen,altered ruminal fermentation,and improved lactation performance in dairy cows.展开更多
Understanding how different livestock species and breeds respond to consumption of brackish water could improve usage of this resource.Therefore,Angora,Boer,and Spanish goat doelings and Dorper,Katahdin,and St.Croix e...Understanding how different livestock species and breeds respond to consumption of brackish water could improve usage of this resource.Therefore,Angora,Boer,and Spanish goat doelings and Dorper,Katahdin,and St.Croix ewe lambs(6 animals per animal type[AT];initial age=296±2.1 days)consuming water with varying concentrations of minerals of a natural brackish water source(BR)and sodium chloride(NaCl;SL)were used to determine effects on water and feed intake,nutrient digestion,heat energy,methane emission,ruminal fluid conditions,and blood constituent concentrations.There were 6 simultaneous 6(water treatments[WT])×6(AT)Latin squares with 3-wk periods.The WT were fresh(FR),BR alone(100-BR),a similar total dissolved solids(TDS)concentration as 100-BR via NaCl addition to FR(100-SL),BR with concentrations of all minerals increased by approximately 50%(150-BR),a similar TDS level as 150-BR by NaCl addition to FR(150-SL),and a similar 150 TDS level achieved by addition of a 1:1 mixture of BR minerals and NaCl to 100-BR(150-BR/SL).Concentrations(mg/kg)in BR were 4928 TDS,85.9 bicarbonate,224.9 calcium,1175 chloride,60.5 magnesium,4.59 potassium,1387sodium,1962 sulfate,and 8.3 boron,and TDS in other WT were 209,5684,7508,8309,and 7319 mg/kg for FR,100-SL,150-BR,150-SL,and 150-BR/SL,respectively.There were very few significant effects of WT or AT×WT interactions,although AT had numerous effects.Water intake was affected by AT(P=0.02)and WT(P=0.04),with greater water intake for 150-SL than for FR,100-BR,100-SL,and 150-BR.Dry matter intake among AT was lowest(P<0.05)for Angora.Digestion of organic matter and neutral detergent fiber and heat energy differed among AT(P<0.05),but nitrogen digestion and ruminal methane emission were similar among AT.Blood aldosterone concentration was higher(P<0.05)for FR than for other WT.In conclusion,all AT seemed resilient to these WT regardless of mineral source and concentrations,with TDS less than 8300 mg/kg,which did not influence nutrient utilization,ruminal fermentation,energy balance,or blood constituent levels.展开更多
To efficiently use lignocellulosic materials in ruminants,it is crucial to explore effective enzymes,especially bifunctional enzymes.In this study,a novel stable bifunctional cellulase-xylanase protein from buffalo ru...To efficiently use lignocellulosic materials in ruminants,it is crucial to explore effective enzymes,especially bifunctional enzymes.In this study,a novel stable bifunctional cellulase-xylanase protein from buffalo rumen metagenome was expressed and characterized,CelXyn2.The enzyme displayed optimal activity at pH 6.0 and 45℃.The residual endoglucanase and xylanase activities were 90.6%and 86.4%after a 60-min pre-incubation at 55℃.Hydrolysis of rice straw,wheat straw,sheepgrass and sugar beet pulp by CelXyn2 showed its ability to degrade both cellulose and hemicellulose polymers.Treatment with CelXyn2 improved the hydrolysis of agricultural residues with an evident increase in production of total gas,lactate and volatile fatty acids.The results of 16S rRNA and real-time PCR showed that the effect on in vitro ruminal microbial community depended on fermenta-tion substrates.This study demonstrated that CelXyn2 could strengthen lignocellulose hydrolysis and in vitro ruminal fermentation.These characteristics of CelXyn2 distinguish it as a promising candidate for agricultural application.展开更多
An in vitro experiment was conducted to evaluate the effects of grain type on in vitro dry matter disappearance (IVDMD) and pH using ruminal fluid and a buffer reagent. Five beef cows were used for ruminal fluid colle...An in vitro experiment was conducted to evaluate the effects of grain type on in vitro dry matter disappearance (IVDMD) and pH using ruminal fluid and a buffer reagent. Five beef cows were used for ruminal fluid collection and ruminal fluid was pooled prior to use. The cows used for ruminal fluid collection were maintained on a forage-based diet (60:40 forage to concentrate) for 28 d prior to ruminal fluid collection. Three grain types were evaluated: 1) dry corn (89% dry matter;DRC), 2) high-moisture corn (72% dry matter;HMC) and 3) rye (89% dry matter;RYE). Data were analyzed as a completely randomized design. A total of twenty-one replications of each grain type were used for statistical analysis (n = 63 tubes total). IVDMD was greater (P ≤ 0.05) by 97.1% and 46.4% for RYE compared to DRC and HMC, respectively. Additionally, IVDMD was greater (P = 0.05) by 34.6% for HMC compared to DRC. Final pH was decreased (P ≤ 0.05) for RYE by 12.3% and 2.8% for RYE compared to DRC and HMC, respectively. Also, final pH was decreased (P = 0.05) by 9.8% for HMC compared to DRC. These data indicate that corn harvest method (dry vs. high-moisture) influences IVDMD and final pH and that rye has a greater disappearance of dry matter and lower final pH than corn under in vitro conditions.展开更多
The effect of tea saponins (TS) on rumen fermentation and methane emission was examined using an in vitro gas production technique named Reading Pressure Technique. Three levels of TS addition (0, 0.2, 0.4 mg/ml) were...The effect of tea saponins (TS) on rumen fermentation and methane emission was examined using an in vitro gas production technique named Reading Pressure Technique. Three levels of TS addition (0, 0.2, 0.4 mg/ml) were evaluated in the faunated and defaunated rumen fluid. Compared to the control, TS addition decreased the 24 h gas production in the faunated rumen fluid, but had a minor effect on gas yield in the defaunated rumen fluid. The TS significantly reduced methane production in vitro. In the faunated rumen fluid, 0.2 or 0.4 mg/ml TS decreased the 24 h methane emission by 12.7% or 14.0%, respectively. Rumen fluid pH value was affected neither by TS addition nor by defaunation. The TS addition had only minor effects on volatile fatty acids, but the yield and pattern of volatile fatty acids were greatly affected by defaunation. While the molar proportion of acetate was not affected by defaunation, the propionate was significantly increased and the butyrate significantly decreased. Ammonia-N concentration and microbial protein yield were influenced by TS inclusion and defaunation. Inclusion of 0.4 mg/ml TS increased the microbial protein mass by 18.4% and 13.8% and decreased the ammonia-N concentration by 8.3% and 19.6% in the faunated and defaunated rumen fluid, respectively. Protozoa counts were significantly reduced by TS inclusion. The current study demonstrated the beneficial effect of TS on methane production and rumen fermentation, and indicated that this may be due to the effect of the associated depression on protozoa counts.展开更多
Background:Methane production and fatty acids(FA)biohydrogenation in the rumen are two main constraints in ruminant production causing environmental burden and reducing food product quality.Rumen functions can be modu...Background:Methane production and fatty acids(FA)biohydrogenation in the rumen are two main constraints in ruminant production causing environmental burden and reducing food product quality.Rumen functions can be modulated by the biologically active compounds(BACs)of plant origins as shown in several studies e.g.reduction in methane emission,modulation of FA composition with positive impact on the ruminant products.Coleus amboinicus Lour.(CAL)contains high concentration of polyphenols that may potentially reduce methane production and modulate ruminal biohydrogenation of unsaturated FA.This study aimed to investigate the effect of BAC of Coleus amboinicus Lour.(CAL)fed to growing lambs on ruminal methane production,biohydrogenation of unsaturated FA and meat characteristics.In this study,the in vitro experiment aiming at determining the most effective CAL dose for in vivo experiments was followed by two in vivo experiments in rumen-cannulated rams and growing lambs.Experiment 1(RUSITEC)comprised of control and three experimental diets differing in CAL content(10%,15%,and 20%of the total diet).The two in vivo experiments were conducted on six growing,rumen-cannulated lambs(Exp.2)and 16 growing lambs(Exp.3).Animals were assigned into the control(CON)and experimental(20%of CAL)groups.Several parameters were examined in vitro(pH,ammonia and VFA concentrations,protozoa,methanogens and select bacteria populations)and in vivo(methane production,digestibility,ruminal microorganism populations,meat quality,fatty acids profiles in rumen fluid and meat,transcript expression of 5 genes in meat).Results:CAL lowered in vitro methane production by 51%.In the in vivo Exp.3,CAL decreased methane production by 20%compared with the CON group,which corresponded to reduction of total methanogen counts by up to 28%in all experiments,notably Methanobacteriales.In Exp.3,CAL increased or tended to increase populations of some rumen bacteria(Ruminococcus albus,Megasphaera elsdenii,Butyrivibrio proteoclasticus,and Butyrivibrio fibrisolvens).Dietary CAL suppressed the Holotricha population,but increased or tended to increase Entodiniomorpha population in vivo.An increase in the polyunsaturated fatty acid(PUFA)proportion in the rumen of lambs was noted in response to the CAL diet,which was mainly attributable to the increase in C18:3 cis-9 cis-12cis-15(LNA)proportion.CAL reduced the mRNA expression of four out of five genes investigated in meat(fatty acid synthase,stearoyl-CoA desaturase,lipoprotein lipase,and fatty acid desaturase 1).Conclusions:Summarizing,polyphenols of CAL origin(20%in diet)mitigated ruminal methane production by inhibiting the methanogen communities.CAL supplementation also improved ruminal environment by modulating ruminal bacteria involved in fermentation and biohydrogenation of FA.Besides,CAL elevated the LNA concentration,which improved meat quality through increased deposition of n-3 PUFA.Highlight·Coleus amboinicus Lour.(CAL)into sheep diet decreased CH4emission.·CAL did not reduce nutrient digestibility,but inhibited the methanogen community.·CAL increased ruminal propionate proportion and decreased acetate/propionate ratio.·CAL elevated n-3 fatty acid concentration in ruminal fluid and meat.·Supplementation of CAL improved some meat quality traits.展开更多
This research proposes a batch in vitro rumen apparatus modified from Daisy incubator and procedures of measuring feed digestion by using nylon bag to replace the traditional centrifuging and filtration methods, for t...This research proposes a batch in vitro rumen apparatus modified from Daisy incubator and procedures of measuring feed digestion by using nylon bag to replace the traditional centrifuging and filtration methods, for the purpose of studying ruminal fermentation. The apparatus consists of 8 sets of airtight reaction vessels which rotated at a speed of 1 r/min and located inside a thermostatic cabin. Optimum procedures was proved to be that the volume of incubation fluid was 400 mL; fineness and size of test feed were 0.125-0.25 mm and 0.4 g, respectively; amount of bags in one vessel was 6; fermentation diet in a single incubation was 4-5 g. Comparing experiments showed that fermentation speed attained with the apparatus was about 15-20% greater than that attained with flask-shaking machine method （revolutionary speed is 100 r/min） and more accurate results could be obtained with the new apparatus. In conclusion, this apparatus could provide an efficient mixing action, and the procedure could allow sensitive detection of differences in ruminal fermentation in a time-saving way.展开更多
Background： The use of antibiotics in animal diets is facing negative feedback due to the hidden danger of drug residues to human health. Traditional Chinese herbal medicine has been used to replace antibiotics in th...Background： The use of antibiotics in animal diets is facing negative feedback due to the hidden danger of drug residues to human health. Traditional Chinese herbal medicine has been used to replace antibiotics in the past two decades and played an increasingly important role in livestock production. The present study was carried out to assess the feeding effects of a traditional nourishing Chinese herbal medicine mixture on kinetics of plasma glucose, protein and energy metabolism in sheep. Ruminal fermentation characteristics were also determined. Methods： Four sheep were fed on either mixed hay （MH-diet） or MH-diet supplemented with 2% of Chinese herbal medicine （mixture of Astragalus root, Angelica root and Atractylodes rhizome; CHM-diet） over two 3S-day periods using a crossover design. The turnover rate of plasma glucose was measured with an isotope dilution method using [U-^13C]glucose. The rates of plasma leucine turnover and leucine oxidation, whole body protein synthesis （WBPS） and metabolic heat production were measured using the [1-^13C]leucine dilution and open circuit calorimetry. Results： Body weight gain of sheep was higher （P = 0.03） for CHM-diet than for MH-diet. Rumen pH was lower （P = 0.02）, concentration of rumen total volatile fatty acid tended to be higher （P = 0.05） and acetate was higher （P = 0.04） for CHM-diet than for MH-diet. Turnover rates of plasma glucose and leucine did not differ between diets. Oxidation rate of leucine tended to be higher （P = 0.06） for CHM-diet than for MH-diet, but the WBPS did not differ between diets. Metabolic heat production tended to be greater （P = 0.05） for CHM-diet than for MH-diet. Conclusions： The sheep fed on CHM-diet had a higher body weight gain and showed positive impacts on rumen fermentation and energy metabolism without resulting in any adverse response. Therefore, these results suggested that the Chinese herbal medicine mixture should be considered as a potential feed additive for sheep.展开更多
It is known that nitrate inhibits ruminal methanogenesis,mainly through competition with hydrogenotrophic methanogens for available hydrogen(H2)and also through toxic effects on the methanogens.However,there is limite...It is known that nitrate inhibits ruminal methanogenesis,mainly through competition with hydrogenotrophic methanogens for available hydrogen(H2)and also through toxic effects on the methanogens.However,there is limited knowledge about its effects on the others members of ruminal microbiota and their metabolites.In this study,we investigated the effects of dietary nitrate inclusion on enteric methane(CH4)emission,temporal changes in ruminal microbiota,and fermentation in Holstein calves.Eighteen animals were maintained in individual pens for 45 d.Animals were randomly allocated to either a control(CTR)or nitrate(NIT,containing 15 g of calcium nitrate/kg dry matter)diets.Methane emissions were estimated using the sulfur hexafluoride(SF6)tracer method.Ruminal microbiota changes and ruminal fermentation were evaluated at 0,4,and 8 h post-feeding.In this study,feed dry matter intake(DMI)did not differ between dietary treatments(P>0.05).Diets containing NIT reduced CH4 emissions by 27%(g/d)and yield by 21%(g/kg DMI)compared to the CTR(P<0.05).The pH values and total volatile fatty acids(VFA)concentration did not differ between dietary treatments(P>0.05)but differed with time,and post-feeding(P<0.05).Increases in the concentrations of ruminal ammonia nitrogen(NH3-N)and acetate were observed,whereas propionate decreased at 4 h post-feeding with the NIT diet(P<0.05).Feeding the NIT diet reduced the populations of total bacteria,total methanogens,Ruminococcus albus and Ruminococcus flavefaciens,and the abundance of Succiniclasticum,Coprococcus,Treponema,Shuttlewortia,Succinivibrio,Sharpea,Pseudobutyrivibrio,and Selenomona(P<0.05);whereas,the population of total fungi,protozoa,Fibrobacter succinogenes,Atopobium and Erysipelotrichaceae L7 AE11 increased(P<0.05).In conclusion,feeding nitrate reduces enteric CH4 emissions and the methanogens population,whereas it decreases the propionate concentration and the abundance of bacteria involved in the succinate and acrylate pathways.Despite the altered fermentation profile and ruminal microbiota,DMI was not influenced by dietary nitrate.These findings suggest that nitrate has a predominantly direct effect on the reduction of methanogenesis and propionate synthesis.展开更多
基金supported by the National Key Technologies R&D Program of China(2012BAD12B02)the Program of International S&T Cooperation of China(2010DFB34230)the Scientific&Technological Innovation Project of Shaanxi,China(2011KTCQ02-02)
文摘We evaluated the effects of neutral detergent soluble fiber （NDSF） and sucrose supplementation on ruminal fermentation, microbial synthesis, and populations of ruminal cellulolytic bacteria using the rumen simulation technique （RUSITEC）. The experiment had a 2x2 factorial design with two dosages of sucrose, low （ca. 0.26 g d-1, low-sucrose） and high （ca. 1.01 g d-1, high-sucrose）, and two dosages of supplied NDSF, low （1.95 g d-1, Iow-NDSF） and high （2.70 g d-1, high-NDSF）. Interactions between NDSF and sucrose were detected for xylanase activity from solid fraction and apparent disappearance of neutral detergent fiber （NDF） and hemicellulose, with the lowest values observed for high-NDSF and high-sucrose treatment. Supplemental NDSF appeared to increase the molar proportion of acetate and reduce that of butyrate; however, the effects of supplemental sucrose on VFA profiles depended upon NDSF amount. There was a NDSFxsucrose interaction for the production of methane. High-NDSF fermenters had lower ammonia-N production, greater daily N flow of solid- associated microbial pellets and total microorganisms, and greater microbial synthesis efficiency compared with low- NDSF fermenters. Supplementation with NDSF resulted in an increase in 16S rDNA copies of Ruminococcusflavefaciens and a reduction in copies of Ruminococcus albus. Supplementation with sucrose tended to increase the 16S rDNA copies ofR. albus from liquid fraction, but did not affect daily total microbial N flow and cellulolytic bacterium populations from solid fraction. These data indicate that the effects of the interaction between NDSF and sugars on ruminal fermentation and fiber digestion should be taken into account in diet formulation. Ruminal fermentation and metabolism of sugars warrant further investigation.
基金supported by the earmarked fund for China Agriculture Research System (CARS-37)Special Fund for Agro-scientific Research in the Public Interest (201303144)
文摘Twenty-eight male, weaned Chinese Holstein calves（（156.8±33.4） kg） were used to investigate the effects of dietary forage to concentrate ratio（F：C） and forage length on nutrient digestibility, plasma metabolites, ruminal fermentation, and fecal microflora. Animals were randomly allocated to four treatments in a 2×2 factorial arrangement： whole-length forage（WL） with low F：C（50：50）; WL with high F：C（65：35）; short-length forage（SL） with high F：C（65：35）; and SL with low F：C（50：50）. Chinese wildrye was used as the only forage source in this trial. The grass in the SL treatments was chopped using a chaff cutter to achieve small particle size（-50% particles 〉19 mm）. Dry matter intake（DMI） and organic matter（OM） intake was increased by increasing both F：C（P〈0.01） and forage length（FL）（P〈0.05）, while acid detergent fiber（ADF） and neutral detergent fiber（NDF） intakes were only increased by increasing the F：C（P〈0.01）. The digestibility of NDF was increased as the FL increased（P〈0.01）, and it was also affected by interaction between F：C and FL（P〈0.05）. Cholesterol（CHO）（P〈0.01）, leptin（LP）（P〈0.05）, and growth hormone（GH）（P〈0.01） concentrations in plasma were increased as dietary F：C increased. A significant increase in plasma triglyceride（TG）（P〈0.01）, insulin（INS）（P〈0.05）, and GH（P〈0.01） levels was observed with decreasing dietary FL. Ruminal p H values of calves fed with low F：C diets were significantly lower than those in high F：C treatment（P〈0.05）. Increasing the F：C enhanced ruminal acetic acid（P〈0.05） and acetic acid/propionic acid（P〈0.01）. Fecal Lactobacillus content was significantly higher, while Escherichia coli and Salmonella contents were significantly lower in WL and high F：C groups（P〈0.05）. Lower fecal scores（higher diarrhea rate） were observed in calves fed with SL hay compared to WL hay（P〈0.05）. Denatured gradient gel electrophoresis（DGGE） bands and richness index（S） were significantly affected by the interaction between F：C and FL（P〈0.05）, under high F：C, band numbers and richness index from WL group were higher than that from SL group（P〈0.05）, whereas there were no differences between WL andSL groups under low F：C（P〉0.05）. Microflora similarity was 50–73% among the different treatments. It is concluded that the WL with high F：C（65：35） diet is suitable for weaned calves.
基金the China Agricultural Research System for providing facility and funds for experiment
文摘This study was conducted to investigate the effect of Soybean Peptides(SPs) on ruminal fermentation and microbial diversity in vitro. Four levels of SPs supplements(0, 0.25%, 0.50% and 0.75% dry matter basis) were tested. p H, NH3-N, Neutral Detergent Fiber(NDF), Acid Detergent Fiber(ADF), Dry Matter Digestibility(DMD) and the Total Volatile Fatty Acid(TVFA) were measured at 6, 24, 48 h of in vitro mixed incubation the fluids. Microbial populations were determined at 24 h and Microbial Proteins(MCP) were determined at 24 and 48 h. The gas production after 48 h in vitro incubation presented linear growth(p<0.05) and the highest content was the level of 0.5% SPs(dry matter basis). NH3-N concentration reached the highest concentration with 0.75%(dry matter basis) at 48 h. p H linearly increased(linear, p<0.05) from 6 to 48 h. The digestion of DMD increased with increasing doses of SPs at 24 h. NDF and ADF linearly(p<0.01) decreased by adding SPs. The concentration of TVFA linearly increased(p<0.05) at 6, 24 and 48 h, and reached the highest concentration at the level of 0.75%(dry matter basis). SPs decreased(p<0.05) the molar proportion of acetate and propionate, respectively at 24 and 48 h. Acetat to Propionate ratio(A/P; linear, p<0.05) increased at 48 h, and reached the greatest value at the level of 0.75%(dry matter basis) at 48 h. The populations of rumen Ruminococcus flavefaciens(R. flavefaciens), Ruminococcusalbus(R. albus), Fibrobacter succinogenes(F. succinogenes), Butyrivibrio fibrisolvens(B. fibrisolvens), Streptococcus bovis(S.bovis), Ruminobacter amylophilus(R. amylophilus) and Succinimonas amylolytica(S. amylolytica) were analyzed based on the total rumen bacterial 16 S ribosomal deoxyribonucleic acid(r DNA). The relative abundance of R. flavefaciens and R. albus increased at 24 h, but the relative abundance of F. succinogenes decreased at this time. The incubation of SPs had no effect on the abundance of S. bovis and R. amylophilus. The relative abundance of B. fibrisolvens and S. amylolytica reached the greatest value(p<0.05) at middle doses of SPs inclusion at 24 h. The value of MCPs linearly increased(p<0.05) at 24 and 48 h. These results showed that SPs could improve in vitro fermentation and nutrient digestion of feed substrates, and had the ability to modulate the ruminal fermentation pattern by regulating the composition of functional rumen microbes. Hence, SPs might be a potential feed additive applied in the diets of ruminants.
基金supported by an earmarked fund for the Modern Agro-industry Technology Research System and National Natural Science Foundation of China (30901030)
文摘The effects of supplemental carbohydrate （CHO） sources on milk yield and composition, nitrogen （N） balance,and ruminal fermentation were evaluated in lactating dairy cows fed energy-deficient total mixed rations （TMR） . Fifty-six lactating Holstein cows （36. 8 ± 3. 4 kg / d of milk yield; 152 ± 26 days in milk [DIM]） were randomly assigned to one of four diets： （1） basal TMR （control） ; （2） basal TMR ＋ 1. 25 kg / d sucrose （SUC） ; （3） basal TMR ＋ 2. 12 kg /d steam-flaked corn （SFC） ; （4） basal TMR ＋ 2. 23 kg / d wheat （WHE） . The trial lasted 70 days,including the first 10 days of adaptation. Simultaneously, a 4 × 4 Latin square trial was conducted with four ruminally cannulated cows of similar DMI （Dry Matter Intake） fed on the above four diets. Each testing period lasted 18 days： 15 days for adaptation and 3 days for sampling. Cows fed SUC-,SFC-,and WHE-supplemented diets produced 1. 6,2. 9,and 0. 8 kg / d,respectively,more milk than those on the basal TMR control diet,but the difference was not significant （P = 0. 160） . However,the production of energy-corrected milk of cows fed CHO-supplemented diets improved significantly （P = 0. 020） ,and the yield of 4% fatcorrected milk tended to be higher （P = 0. 063） than in control animals. Percentages of milk protein,lactoseand solids-not-fat （SNF） increased significantly in cows fed CHO-supplemented diets （P 〈 0. 05） ,and yields of milk protein and SNF were significantly higher （P 〈0. 05） ; yields of milk fat and lactose were somewhat higher （P 〈 0. 10） . Cows receiving supplementary CHO diets consumed more DM （Dry Matter） （P = 0. 023） ; however,there was no significant difference in N retention,digestibility,or utilization efficiency among the treatments （P 〉 0. 10） . The average ruminal pH was lowest in cows supplemented with SUC,while that in cows supplemented with SFC and WHE was only slightly reduced （P = 0. 025） . Ruminal NH 3 -N concentration was highest with no supplementary CHO （P = 0. 017） ,and changes in postfeeding time were similar across the diets. Total volatile fatty acid concentration was significantly lower in control animals than in those on SUCand WHE-supplemented diets （P = 0. 001） ; significant dietary responses were observed in the concentrations of acetate,butyrate,and branchedchain fatty acids and in the acetate-to-propionate ratio （P 〈0. 001） . These results indicate that supplementation with different CHO sources in energy-deficient diets substantially improved the balance of energy and N in the rumen,altered ruminal fermentation,and improved lactation performance in dairy cows.
基金supported by the USDA National Institute for Food and Agriculture(NIFA),Project OKLUGOETSCH2019(Accession Number 1018979)the USDA NIFA Evans-Allen Project OKLUSAHLU2017(Accession Number 1012650)
文摘Understanding how different livestock species and breeds respond to consumption of brackish water could improve usage of this resource.Therefore,Angora,Boer,and Spanish goat doelings and Dorper,Katahdin,and St.Croix ewe lambs(6 animals per animal type[AT];initial age=296±2.1 days)consuming water with varying concentrations of minerals of a natural brackish water source(BR)and sodium chloride(NaCl;SL)were used to determine effects on water and feed intake,nutrient digestion,heat energy,methane emission,ruminal fluid conditions,and blood constituent concentrations.There were 6 simultaneous 6(water treatments[WT])×6(AT)Latin squares with 3-wk periods.The WT were fresh(FR),BR alone(100-BR),a similar total dissolved solids(TDS)concentration as 100-BR via NaCl addition to FR(100-SL),BR with concentrations of all minerals increased by approximately 50%(150-BR),a similar TDS level as 150-BR by NaCl addition to FR(150-SL),and a similar 150 TDS level achieved by addition of a 1:1 mixture of BR minerals and NaCl to 100-BR(150-BR/SL).Concentrations(mg/kg)in BR were 4928 TDS,85.9 bicarbonate,224.9 calcium,1175 chloride,60.5 magnesium,4.59 potassium,1387sodium,1962 sulfate,and 8.3 boron,and TDS in other WT were 209,5684,7508,8309,and 7319 mg/kg for FR,100-SL,150-BR,150-SL,and 150-BR/SL,respectively.There were very few significant effects of WT or AT×WT interactions,although AT had numerous effects.Water intake was affected by AT(P=0.02)and WT(P=0.04),with greater water intake for 150-SL than for FR,100-BR,100-SL,and 150-BR.Dry matter intake among AT was lowest(P<0.05)for Angora.Digestion of organic matter and neutral detergent fiber and heat energy differed among AT(P<0.05),but nitrogen digestion and ruminal methane emission were similar among AT.Blood aldosterone concentration was higher(P<0.05)for FR than for other WT.In conclusion,all AT seemed resilient to these WT regardless of mineral source and concentrations,with TDS less than 8300 mg/kg,which did not influence nutrient utilization,ruminal fermentation,energy balance,or blood constituent levels.
基金supported by the Carbon Peak&Carbon Neutralization Innovation Project of Jiangsu Province(BE2022309)Natural Science Foundation of China(32061143034,32161143028)+1 种基金the Fundamental Research Funds for the Central Universities(lzujbky-2022-ct04)the National Modern Agricultural Industry Technology System Guangxi Dairy Buffalo Innovation Team Project(nycytxgxcxtd-2021-21).
文摘To efficiently use lignocellulosic materials in ruminants,it is crucial to explore effective enzymes,especially bifunctional enzymes.In this study,a novel stable bifunctional cellulase-xylanase protein from buffalo rumen metagenome was expressed and characterized,CelXyn2.The enzyme displayed optimal activity at pH 6.0 and 45℃.The residual endoglucanase and xylanase activities were 90.6%and 86.4%after a 60-min pre-incubation at 55℃.Hydrolysis of rice straw,wheat straw,sheepgrass and sugar beet pulp by CelXyn2 showed its ability to degrade both cellulose and hemicellulose polymers.Treatment with CelXyn2 improved the hydrolysis of agricultural residues with an evident increase in production of total gas,lactate and volatile fatty acids.The results of 16S rRNA and real-time PCR showed that the effect on in vitro ruminal microbial community depended on fermenta-tion substrates.This study demonstrated that CelXyn2 could strengthen lignocellulose hydrolysis and in vitro ruminal fermentation.These characteristics of CelXyn2 distinguish it as a promising candidate for agricultural application.
文摘An in vitro experiment was conducted to evaluate the effects of grain type on in vitro dry matter disappearance (IVDMD) and pH using ruminal fluid and a buffer reagent. Five beef cows were used for ruminal fluid collection and ruminal fluid was pooled prior to use. The cows used for ruminal fluid collection were maintained on a forage-based diet (60:40 forage to concentrate) for 28 d prior to ruminal fluid collection. Three grain types were evaluated: 1) dry corn (89% dry matter;DRC), 2) high-moisture corn (72% dry matter;HMC) and 3) rye (89% dry matter;RYE). Data were analyzed as a completely randomized design. A total of twenty-one replications of each grain type were used for statistical analysis (n = 63 tubes total). IVDMD was greater (P ≤ 0.05) by 97.1% and 46.4% for RYE compared to DRC and HMC, respectively. Additionally, IVDMD was greater (P = 0.05) by 34.6% for HMC compared to DRC. Final pH was decreased (P ≤ 0.05) for RYE by 12.3% and 2.8% for RYE compared to DRC and HMC, respectively. Also, final pH was decreased (P = 0.05) by 9.8% for HMC compared to DRC. These data indicate that corn harvest method (dry vs. high-moisture) influences IVDMD and final pH and that rye has a greater disappearance of dry matter and lower final pH than corn under in vitro conditions.
基金Project (No. 12665/R0) supported partly by Co-ordinated ResearchProjects from Joint FAO/IAEA Division, IAEA
文摘The effect of tea saponins (TS) on rumen fermentation and methane emission was examined using an in vitro gas production technique named Reading Pressure Technique. Three levels of TS addition (0, 0.2, 0.4 mg/ml) were evaluated in the faunated and defaunated rumen fluid. Compared to the control, TS addition decreased the 24 h gas production in the faunated rumen fluid, but had a minor effect on gas yield in the defaunated rumen fluid. The TS significantly reduced methane production in vitro. In the faunated rumen fluid, 0.2 or 0.4 mg/ml TS decreased the 24 h methane emission by 12.7% or 14.0%, respectively. Rumen fluid pH value was affected neither by TS addition nor by defaunation. The TS addition had only minor effects on volatile fatty acids, but the yield and pattern of volatile fatty acids were greatly affected by defaunation. While the molar proportion of acetate was not affected by defaunation, the propionate was significantly increased and the butyrate significantly decreased. Ammonia-N concentration and microbial protein yield were influenced by TS inclusion and defaunation. Inclusion of 0.4 mg/ml TS increased the microbial protein mass by 18.4% and 13.8% and decreased the ammonia-N concentration by 8.3% and 19.6% in the faunated and defaunated rumen fluid, respectively. Protozoa counts were significantly reduced by TS inclusion. The current study demonstrated the beneficial effect of TS on methane production and rumen fermentation, and indicated that this may be due to the effect of the associated depression on protozoa counts.
基金funded by the National Science Centre funding program Grant 2018/31/N/NZ9/01589。
文摘Background:Methane production and fatty acids(FA)biohydrogenation in the rumen are two main constraints in ruminant production causing environmental burden and reducing food product quality.Rumen functions can be modulated by the biologically active compounds(BACs)of plant origins as shown in several studies e.g.reduction in methane emission,modulation of FA composition with positive impact on the ruminant products.Coleus amboinicus Lour.(CAL)contains high concentration of polyphenols that may potentially reduce methane production and modulate ruminal biohydrogenation of unsaturated FA.This study aimed to investigate the effect of BAC of Coleus amboinicus Lour.(CAL)fed to growing lambs on ruminal methane production,biohydrogenation of unsaturated FA and meat characteristics.In this study,the in vitro experiment aiming at determining the most effective CAL dose for in vivo experiments was followed by two in vivo experiments in rumen-cannulated rams and growing lambs.Experiment 1(RUSITEC)comprised of control and three experimental diets differing in CAL content(10%,15%,and 20%of the total diet).The two in vivo experiments were conducted on six growing,rumen-cannulated lambs(Exp.2)and 16 growing lambs(Exp.3).Animals were assigned into the control(CON)and experimental(20%of CAL)groups.Several parameters were examined in vitro(pH,ammonia and VFA concentrations,protozoa,methanogens and select bacteria populations)and in vivo(methane production,digestibility,ruminal microorganism populations,meat quality,fatty acids profiles in rumen fluid and meat,transcript expression of 5 genes in meat).Results:CAL lowered in vitro methane production by 51%.In the in vivo Exp.3,CAL decreased methane production by 20%compared with the CON group,which corresponded to reduction of total methanogen counts by up to 28%in all experiments,notably Methanobacteriales.In Exp.3,CAL increased or tended to increase populations of some rumen bacteria(Ruminococcus albus,Megasphaera elsdenii,Butyrivibrio proteoclasticus,and Butyrivibrio fibrisolvens).Dietary CAL suppressed the Holotricha population,but increased or tended to increase Entodiniomorpha population in vivo.An increase in the polyunsaturated fatty acid(PUFA)proportion in the rumen of lambs was noted in response to the CAL diet,which was mainly attributable to the increase in C18:3 cis-9 cis-12cis-15(LNA)proportion.CAL reduced the mRNA expression of four out of five genes investigated in meat(fatty acid synthase,stearoyl-CoA desaturase,lipoprotein lipase,and fatty acid desaturase 1).Conclusions:Summarizing,polyphenols of CAL origin(20%in diet)mitigated ruminal methane production by inhibiting the methanogen communities.CAL supplementation also improved ruminal environment by modulating ruminal bacteria involved in fermentation and biohydrogenation of FA.Besides,CAL elevated the LNA concentration,which improved meat quality through increased deposition of n-3 PUFA.Highlight·Coleus amboinicus Lour.(CAL)into sheep diet decreased CH4emission.·CAL did not reduce nutrient digestibility,but inhibited the methanogen community.·CAL increased ruminal propionate proportion and decreased acetate/propionate ratio.·CAL elevated n-3 fatty acid concentration in ruminal fluid and meat.·Supplementation of CAL improved some meat quality traits.
文摘This research proposes a batch in vitro rumen apparatus modified from Daisy incubator and procedures of measuring feed digestion by using nylon bag to replace the traditional centrifuging and filtration methods, for the purpose of studying ruminal fermentation. The apparatus consists of 8 sets of airtight reaction vessels which rotated at a speed of 1 r/min and located inside a thermostatic cabin. Optimum procedures was proved to be that the volume of incubation fluid was 400 mL; fineness and size of test feed were 0.125-0.25 mm and 0.4 g, respectively; amount of bags in one vessel was 6; fermentation diet in a single incubation was 4-5 g. Comparing experiments showed that fermentation speed attained with the apparatus was about 15-20% greater than that attained with flask-shaking machine method （revolutionary speed is 100 r/min） and more accurate results could be obtained with the new apparatus. In conclusion, this apparatus could provide an efficient mixing action, and the procedure could allow sensitive detection of differences in ruminal fermentation in a time-saving way.
文摘Background： The use of antibiotics in animal diets is facing negative feedback due to the hidden danger of drug residues to human health. Traditional Chinese herbal medicine has been used to replace antibiotics in the past two decades and played an increasingly important role in livestock production. The present study was carried out to assess the feeding effects of a traditional nourishing Chinese herbal medicine mixture on kinetics of plasma glucose, protein and energy metabolism in sheep. Ruminal fermentation characteristics were also determined. Methods： Four sheep were fed on either mixed hay （MH-diet） or MH-diet supplemented with 2% of Chinese herbal medicine （mixture of Astragalus root, Angelica root and Atractylodes rhizome; CHM-diet） over two 3S-day periods using a crossover design. The turnover rate of plasma glucose was measured with an isotope dilution method using [U-^13C]glucose. The rates of plasma leucine turnover and leucine oxidation, whole body protein synthesis （WBPS） and metabolic heat production were measured using the [1-^13C]leucine dilution and open circuit calorimetry. Results： Body weight gain of sheep was higher （P = 0.03） for CHM-diet than for MH-diet. Rumen pH was lower （P = 0.02）, concentration of rumen total volatile fatty acid tended to be higher （P = 0.05） and acetate was higher （P = 0.04） for CHM-diet than for MH-diet. Turnover rates of plasma glucose and leucine did not differ between diets. Oxidation rate of leucine tended to be higher （P = 0.06） for CHM-diet than for MH-diet, but the WBPS did not differ between diets. Metabolic heat production tended to be greater （P = 0.05） for CHM-diet than for MH-diet. Conclusions： The sheep fed on CHM-diet had a higher body weight gain and showed positive impacts on rumen fermentation and energy metabolism without resulting in any adverse response. Therefore, these results suggested that the Chinese herbal medicine mixture should be considered as a potential feed additive for sheep.
基金supported by a grant from the Fon Cy T-Argentina:PICT 2015-294,PID MS-UTNBA-0004540 and INTA I058Dra Milka Popova(from INRAE-France)for the support in the bioinformatics analysisEng.Ricardo Bualo and Ricardo Arias for their help and technical support in methane emission measurements。
文摘It is known that nitrate inhibits ruminal methanogenesis,mainly through competition with hydrogenotrophic methanogens for available hydrogen(H2)and also through toxic effects on the methanogens.However,there is limited knowledge about its effects on the others members of ruminal microbiota and their metabolites.In this study,we investigated the effects of dietary nitrate inclusion on enteric methane(CH4)emission,temporal changes in ruminal microbiota,and fermentation in Holstein calves.Eighteen animals were maintained in individual pens for 45 d.Animals were randomly allocated to either a control(CTR)or nitrate(NIT,containing 15 g of calcium nitrate/kg dry matter)diets.Methane emissions were estimated using the sulfur hexafluoride(SF6)tracer method.Ruminal microbiota changes and ruminal fermentation were evaluated at 0,4,and 8 h post-feeding.In this study,feed dry matter intake(DMI)did not differ between dietary treatments(P>0.05).Diets containing NIT reduced CH4 emissions by 27%(g/d)and yield by 21%(g/kg DMI)compared to the CTR(P<0.05).The pH values and total volatile fatty acids(VFA)concentration did not differ between dietary treatments(P>0.05)but differed with time,and post-feeding(P<0.05).Increases in the concentrations of ruminal ammonia nitrogen(NH3-N)and acetate were observed,whereas propionate decreased at 4 h post-feeding with the NIT diet(P<0.05).Feeding the NIT diet reduced the populations of total bacteria,total methanogens,Ruminococcus albus and Ruminococcus flavefaciens,and the abundance of Succiniclasticum,Coprococcus,Treponema,Shuttlewortia,Succinivibrio,Sharpea,Pseudobutyrivibrio,and Selenomona(P<0.05);whereas,the population of total fungi,protozoa,Fibrobacter succinogenes,Atopobium and Erysipelotrichaceae L7 AE11 increased(P<0.05).In conclusion,feeding nitrate reduces enteric CH4 emissions and the methanogens population,whereas it decreases the propionate concentration and the abundance of bacteria involved in the succinate and acrylate pathways.Despite the altered fermentation profile and ruminal microbiota,DMI was not influenced by dietary nitrate.These findings suggest that nitrate has a predominantly direct effect on the reduction of methanogenesis and propionate synthesis.
