冷季补饲调控瘤胃菌群结构提高放牧牦牛生产性能OA

This study aims to investigate the effects of supplementary feeding during the cold season on the growth performance,blood metabolism,and rumen microbial community structure of grazing yaks.Twenty-six yaks with similar health,age,and weight(167±6.48)kg from the same pasture were selected for grazing.They were randomly divided into two groups of 13 yaks each according to the experimental design.The control group yaks were not supplemented with concentrated feed after returning from the pasture,while the experimental group yaks were supplemented with 1.5 kg of concentrated feed per head after returning from the pasture.In addition,all groups were supplemented with 0.5 kg of oat silage per head.The preliminary trial period was 7 days,and the actual trial period was 60 days.The results indicated that the final body weight and average daily weight gain of yaks in the experimental group were significantly higher than those of the control group(P<0.05),with the experimental group yaks showing a weight increase of 21.01%during the testing period.The concentration of GLU in the serum of the experimental group yaks was significantly higher than that of the control group(P<0.001),while the concentrations of TC,HDL,and LDL were significantly lower than those of the control group(P<0.001).Compared to the control group,the Chao1 species richness index and Shannon diversity index of the rumen microbial community in the experimental group yaks were significantly lower(P<0.001).In the experimental group,the relative abundance of microbial communities such as Bacteroidota,Prevotellaceae,and Ruminococcaceae in the yak rumen increased,while the relative abundance of Firmicutes,Rikenellaceae,and Lachnospiraceae decreased.At the same time,short-chain fatty acid-producing bacteria such as Roseburia,Succinivibrio,and Anaerovibrio were significantly enriched in the rumen of the experimental group yaks(P<0.05),whereas fiber-degrading bacteria such as Quinella,Fretibacterium,and Oscillospira were significantly enriched in the rumen of the control group yaks(P<0.05).In summary,supplementing with appropriate concentrated feed after the yaks returned from the pasture during the cold season significantly increases the relative abundance of ruminal short-chain fatty acid-producing bacteria,raises the blood glucose concentration,and thereby enhances the productivity of the yaks.