Effects of concentrate supplementation on serum biochemical indexes and rumen micorflora of grazing yaks in the cold season

ZHANG Ben; DING Ziqiang; KANG Yandong; ZHAO Suonan; YANG Tao; BAIMA Duojie; SUOANG Qiupei; GUO Xian

doi:10.13557/j.cnki.issn1002-2813.2025.15.003

Abstract：The experiment aimed to investigate the effects of concentrate supplementation in the cold season on serum biochemical indexes and rumen microflora of grazing yaks.A total of 40 six-year-old yaks were randomly divided into two groups,with five replicates per group and four yaks per replicate.The grazing group only grazed,while the supplementary feeding group was fed 1 kg of concentrate before grazing and after grazing,respectively.The pre-test period was 10 days,and the formal test period was 90 days.The results showed that compared with the grazing group,the concentrations of total protein and albumin,and the activities of aspartate aminotransferase,alanine aminotransferase,lactate dehydrogenase and alkaline phosphatase were significantly increased in the supplementary feeding group(P＜0.05).16S rDNA sequencing indicated that at the phylum level,Bacteroidota,Firmicutes_A,Verrucomicrobiota,Firmicutes_C and Firmicutes_D were the dominant phyla in the rumen fluid samples of the two groups.At the genus level,Prevotella,Bacteroides,Limimorpha,RF16 and SFMI01 were the dominant genera.Compared with the grazing group,the relative abundance of Firmicutes,Prevotella,SFMI01,UBA4334 and UBA1711 were significantly increased(P＜0.05),the relative abundances of Bacteroidota,Bacteroides,RF16,UBA1067 and Fibrobacter were significantly decreased(P＜0.05).The abundances of rumen microbiota in amino acid biosynthesis,fermentation,carbohydrate degradation and carboxylic acid degradation pathways were significantly increased in the supplementary feeding group(P＜0.05).The study indicates that concentrate supplementation in the cold season can significantly improve serum biochemistry and rumen fermentation,and reduce rumen flora richness and diversity,and enhance the energy supply,material metabolism and immunity of grazing yaks.