饲粮不同淀粉水平对牦牛生长性能及粪便菌群结构的影响OA

This experiment aimed to investigate the effects of dietary different starch levels on growth perform-ance and fecal microbiota structure of yaks.Thirty healthy 3-year-old male yaks with similar body weight[(138±12)kg]were randomly divided into 3 groups with 10 yaks in each group.The dietary starch levels of 3 groups were 24%(LL group),27%(ML group)and 30%(HL group),respectively.The pre-experimen-tal period lasted for 10 days,and the experimental period lasted for 60 days.The results showed as follows:1)there were no significant differences in the final body weight and average daily gain of yaks among all groups(P＞0.05),but the final body weight and average daily gain of ML group were the highest.2)The Chao1 in-dex,Observed_features index,Shannon index and Simpson index of LL group were extremely significantly higher than those of ML group and HL group(P＜0.01).3)At the phylum level,the relative abundances of Firmicutes and Bacteroidota in feces of ML group were the highest,which were 63.76%and 32.04%,respec-tively;the fecal Firmicutes relative abundance of ML group was significantly higher than that of HL group(P＜0.05),and the fecal Proteobacteria relative abundance of HL group was extremely significantly higher than of LL group and ML group(P＜0.01).At the genus level,the fecal UCG-005 relative abundance of ML group was the highest,which was 31.75%;the fecal UCG-005 relative abundances of LL group and HL group were 28.83%and 7.91%,respectively;the fecal potential pathogens such as Escherichia_Shigella relative abun-dance of HL group was higher.In conclusion,the dietary starch level influences the fecal microbiota diversity of yak by regulating the gut microbiota structure.Compare with the 24%and 30%starch levels,the 27%starch level is conducive to improving the growth performance of yaks,and the fecal microbiota diversity of yaks is moderate,with a higher relative abundance of beneficial bacteria,and no pathogenic bacteria present,making it more suitable for the intestinal tract of yaks.[Chinese Journal of Animal Nutrition,2026,38(3):2056-2067]