小肽与酵母培养物对舍饲牦牛瘤胃微生物多样性和发酵参数的影响

为研究添加小肽与酵母培养物对舍饲育肥牦牛瘤胃微生物多样性和发酵参数的影响,试验选取36头年龄为4周岁左右、体重水平相当、健康状况良好的麦洼牦牛,随机分为4个处理组,对照组饲喂全混合日粮(TMR),试验Ⅰ、Ⅱ、Ⅲ组在TMR基础上分别添加1%酵母培养物、0.75%小肽、1%酵母培养物+0.75%小肽。试验结果表明:(1)四个处理组的优势菌门均为拟杆菌门(Bacteroidetes)、厚壁菌门(Firmicutes)、互养菌门(Synergistests)和变形菌门(Proteobacteria)。小肽和酵母培养物的添加显著降低了变形菌门的相对丰度(P<0.05),提高了拟杆菌门和互养菌门的相对丰度,但差异不显著(P>0.05)。从属水平分析,拟杆菌科的BS11菌属(Bacteroidetes BS11 gut group)、理研菌科RC9菌属(Rikenellaceae RC9 gut group)、普雷沃氏菌属(Prevotella 1)、克里斯滕森菌科的R7菌属(Christensenellaceae R 7 group)为四个处理组共有优势菌属。添加小肽和酵母培养物,显著提高了理研菌科RC9菌属、普雷沃氏菌属、疣微菌科UCG-010菌属(Ruminococcaceae_UCG-010)、帕匹杆菌属(Papillibacter)、柔膜菌纲RF9菌属(Mollicutes_RF9)的相对丰度(P<0.05)。(2)小肽与酵母培养物单独添加或同时添加对瘤胃中pH和氨态氮(NH3-N)浓度无显著影响(P>0.05);降低了瘤胃中乙酸浓度,但差异不显著(P>0.05);1%酵母培养物组和1%酵母培养物+0.75%小肽组显著提高了瘤胃中丙酸浓度(P<0.05),0.75%小肽组虽提高了瘤胃中丙酸浓度,但差异不显著(P>0.05);小肽与酵母培养物单独添加或同时添加都显著降低了乙/丙(P<0.05),表明瘤胃发酵从乙酸型向丙酸型转变,有利于能量利用效率的提高。综上所述,小肽与酵母培养物单独或同时添加都促进了瘤胃有益菌群生长,使瘤胃发酵从乙酸型向丙酸型转变,提高了能量利用效率,小肽与酵母培养物合用具有叠加效应。

Effects of small peptide and yeast culture on rumen microbial diversity and fermentation parameters of yaks

The aim of this study was to investigate the effects of adding small peptides and yeast cultures on the apparent digestibility,production performance and blood biochemical parameters of the fattening calves.Thirty-six wheat yak aged 4 years old,with similar body weight and good health were randomly divided into 4 treatment groups,control group(TMR full mixed diet),experiment group I(TMR+1%yeast culture),experiment group II(TMR+0.75%small peptide),experiment group III(TMR+1%yeast culture+0.75%small peptide).The results showed that:(1)The dominant bacteria in the four treatment groups were Bacteroidetes,Firmicutes,Synergistests,Proteobacteria.Small peptide and yeast culture significantly reduced the relative abundance of Proteobacteria(P<0.05),the relative abundance of Bacteroides and Synergistests increased,but the difference was not significant(P>0.05).Subordinate level analysis,Bacteroidetes BS11 gut group,Rikenellaceae RC9 gut group,Prevotella 1,Christensenellaceae R 7 group for four treatment groups has a dominant genus.Addition of small peptides and yeast cultures significantly increased the relative abundance of the Rikenellaceae RC9 gut group,Prevotellaceae_UCG-004,Ruminococcaceae_UCG-010 and Papillibacter,Mollicutes_RF9(P<0.05).(2)The addition of small peptide and yeast culture alone or at the same time had no significant effect on pH and ammonia nitrogen concentration in the rumen(P>0.05);the concentration of acetic acid in the rumen was decreased,but the difference was not significant(P>0.05);The 1%yeast culture group and 1%yeast culture+0.75%small peptide group significantly increased the concentration of propionic acid in the rumen(P<0.05),while the0.75%small peptide group increased the concentration of propionic acid in the rumen,but the difference was not significant(P>0.05);small peptide and yeast culture alone or simultaneously added significantly reduced the acetic acid/propionic acid value(P<0.05),indicated that the rumen fermentation from acetic acid type to propionic acid type conversion,which was conducive to the improvement of energy use efficiency.In summary,the addition of small peptides and yeast cultures alone or simultaneously promote the growth of beneficial rumen bacteria,transform rumen fermentation from acetic acid to propionic acid,and improve energy utilization efficiency,small peptides and yeast cultures have additive effect.