饲粮添加赖氨酸对肉牛粪便发酵参数和微生物菌群结构的影响OA北大核心CSTPCD

This study was conducted to investigate the effects of dietary lysine supplementation on fecal fermentation parameters,microbial diversity and microflora structure of beef cattle.Four healthy Jinjiang cattle with similar body weight were randomly divided into two groups with two cattle in each group.A repeated 2×2 Latin square design was adopted with the control group fed the basal diet and the treatment group fed the basal diet+0.20％of lysine.The experiment lasted for 30 days and was divided into 2 phases,in which the first 10 days of each phase designated as the adaptation period and the last 5 days being the sample collection period.Fecal samples were collected and then analyzed for fermentation parameters,microbial diversity and microflora structure.The results showed as follows:1)Dietary supplementation of lysine significantly increased the concentrations of isobutyrate,isovalerate and branched-chain volatile fatty acids in feces(P＜0.05);2)Lysine supplementation had no significant effect on fecal microbial richness and evenness(P＞0.05);3)Taxonomic annotation found that the supplementation of lysine significantly increased the relative abundance of Lachnospiraceae NK 4A136 group in feces,whilst the relative abundance of Christensenellaceae R-7 group was decreased as compared to the control group(P＜0.05);4)Both principal coordinate analysis(PCoA)and analysis of similarity(ANOSIM)showed that lysine supplementation had no significant effect on fecal microbial community structure.In conclusion,dietary supplementation of 0.20％lysine could improve the concentrations of isobutyrate,isovalerate and branched-chain volatile fatty acids in feces,as well as alterations in the relative abundances of Lachnospiraceae NK4A136 group and Christensenellaceae R-7 group,but has no significant effect on fecal microbial diversity and microflora structure.