摘要
为了研究茶渣对奶牛瘤胃发酵参数和微生物菌群多样性的影响,试验基于体外模拟瘤胃发酵试验技术,采用单因子试验设计,构建了 6组不同茶渣添加剂量的发酵体系,其中对照组不添加茶渣,试验Ⅰ～Ⅴ组茶渣添加量分别为饲粮干物质的5％、10％、15％、20％、25％,每个处理组3个重复,发酵24 h后,取发酵体系瘤胃液,采用16S rDNA技术进行瘤胃微生物多样性分析.结果表明:(1)饲粮中添加不同比例的茶渣对奶牛体外瘤胃发酵体系中pH和MCP浓度无显著性影响(P＞0.05);随着茶渣添加量的提高,试验Ⅱ、Ⅲ、Ⅳ、Ⅴ组的NH3-N浓度均显著低于对照组、Ⅰ组(P＜0.05);试验Ⅳ组乙酸、丙酸、丁酸、异丁酸浓度和TVFA含量显著高于对照组和其他各试验组(P＜0.05),Ⅴ组的乙酸/丙酸值显著高于Ⅰ、Ⅱ、Ⅲ、Ⅳ组(P＜0.05),Ⅰ、Ⅱ组的乙酸/丙酸值显著低于对照组、Ⅲ、Ⅳ组(P＜0.05),但两者之间差异不显著.(2)组间瘤胃微生物菌群组成具有相似性,6组样本在门水平上的主要菌门均为拟杆菌门(Bacteroidota)、厚壁菌门(Firmicutes)、变形菌门(Proteobacteria)、螺旋体门(Spirochaetota)、疫微菌门(Verru-comicrobiota)、Patescibacteria、蓝藻菌门(Cyanobacteria)、纤维杆菌门(Fibrobacterota),茶渣添加量为饲粮干物质的25％时,与对照组相比,试验Ⅴ组拟杆菌门、螺旋体门及纤维杆菌门相对丰度显著升高(P＜0.05),厚壁菌门相对丰度显著降低(P＜0.05),试验Ⅰ、Ⅱ、Ⅲ及Ⅳ组差异均不显著(P＞0.05).(3)与对照组相比,试验Ⅰ、Ⅱ、Ⅲ、Ⅳ及Ⅴ组的Ace指数、Chao1指数、Shannon指数和Simpson指数差异均不显著(P＞0.05).(4)与试验组相比,脱硫弧菌属(Des-ulfovibrio)、瘤胃球菌属(Ruminococcus)和克里斯滕森菌科(Christensenellaceae)在对照组富集.综上所述,本试验条件下,饲粮中添加茶渣会降低瘤胃NH3-N浓度,提高TVFA含量,提高拟杆菌门、螺旋体门及纤维杆菌门的相对丰度,降低厚壁菌门的相对丰度,但不会显著改变瘤胃微生物菌群多样性指数.
Abstract
To study the effects of tea residue on rumen microflora diversity of dairy cows,six groups of fermentation systems with different tea residue supplemental dosages were constructed by sin-gle factor design based on in vitro simulated rumen fermentation test technology,in which the control group did not add tea residue,the addition levels of tea leaves in experimental groups Ⅰ toⅤ were 5％,10％,15％,20％and 25％of the dietary dry matter,respectively.Each treatment group had three replicates.After 24 h fermentation,rumen fluid of fermentation system was taken and the microbial diversity in rumen was analyzed by using 16S rDNA technique.The results showed that:(1)Adding different proportions of tea residue to the diet did not significantly affect the pH and MCP concentration in the in vitro rumen fermentation system of dairy cows(P＞0.05);as the amount of tea residue added increased,the NH3-N concentrations in experimental groups Ⅱ,Ⅲ,Ⅳ,and Ⅴ were significantly lower than those in control and Ⅰ groups(P＜0.05);the concentration of acetic acid,propionic acid,butyric acid,isobutyric acid and TVFA content in group Ⅳ were significantly higher than those in the control group and other test groups(P＜0.05);the acetic acid/propionic acid value in group Ⅴ was significantly higher than that in groupⅠ,Ⅱ,Ⅲ,and Ⅳ(P＜0.05);the acetic acid/propionic acid value in group Ⅰ and Ⅱ was signifi-cantly lower than that in the control group,Ⅲ,and Ⅳ(P＜0.05),but there was no significant difference between the two groups.(2)The composition of rumen microflora was similar between groups.At the phylum level,the main phyla of all the six groups were Bacteroidota,Firmicutes,Proteobacteria,Spirochaetota,Verrucomicrobiota,Patescibacteria,Cyanobacteria and Fibrobactero-ta.When the tea residue supplemental level was 25％of dietary dry matter,the relative abundance of Bacteroidota,Spirochaetota and Fibrobacterota in test Ⅴ group was significantly increased com-pared with the control group(P＜0.05),the relative abundance of Firmicutes was significantly de-creased(P＜0.05),there was no significant difference between Ⅰ,Ⅱ,Ⅲ and Ⅳ group(P＞0.05).(3)Compared with the control group,there were no significant differences in Ace index,Chao1 in-dex,Shannon index and Simpson index in Ⅰ,Ⅱ,Ⅲ,Ⅳ and Ⅴ groups(P＞0.05).(4)Compared with the experimental group,Desulfovibrio,Ruminococcus and Christensenellaceae were enriched in the control group.In conclusion,the addition of tea residue in the diet would reduce the concen-tration of NH3-N and increase the content of TVFA in the rumen,and the relative abundance of Bacteroidetes,Spirochaetota and Fibrobacterota were increased and the relative abundance of Firm-icutes was decreased,but the rumen microflora diversity index of dairy cows was not significantly affected by tea residue.
基金项目
河南省重点研发与推广专项(科技攻关)(202102110087)
河南牧业经济学院博士科研启动资金资助项目(2018HNUAHEDF041)
NETL
NSTL
万方数据