Rumen fermentation and microbial diversity of sheep fed a high-concentrate diet supplemented with hydroethanolic extract of walnut green husks

作者：Huan Wei, Jiancheng Liu, Mengjian Liu, Huiling Zhang, Yong Chen · 发表于：Animal Bioscience · 年份：2023 · DOI：10.5713/ab.23.0213 · 被引用次数：19 · 研究领域：Ruminant Nutrition and Digestive Physiology、Effects of Environmental Stressors on Livestock、Agroforestry and silvopastoral systems

OBJECTIVE: This study aimed to assess the impact of a hydroethanolic extract of walnut green husks (WGH) on rumen fermentation and the diversity of bacteria, methanogenic archaea, and fungi in sheep fed a high-concentrate diet. METHODS: Five healthy small-tailed Han ewes with permanent rumen fistula were selected and housed in individual pens. This study adopted a self-controlled and crossover design with a control period and an experimental period. During the control period, the animals were fed a basal diet (with a ratio of concentrate to roughage of 65:35), while during the treatment period, the animals were fed the basal diet supplemented with 0.5% hydroethanolic extract of WGH. Fermentation parameters, digestive enzyme activities, and microbial diversity in rumen fluid were analyzed. RESULTS: Supplementation of hydroethanolic extract of WGH had no significant effect on feed intake, concentrations of total volatile fatty acids, isovalerate, ammonia nitrogen, and microbial protein (p>0.05). However, the ruminal pH, concentrations of acetate, butyrate and isobutyrate, the ratio of acetate to propionate, protozoa count, and the activities of filter paper cellulase and cellobiase were significantly increased (p<0.05), while concentrations of propionate and valerate were significantly decreased (p<0.05). Moreover, 16S rRNA gene sequencing revealed that the relative abundance of rumen bacteria Christensenellaceae R7 group, Saccharofermentans, and Ruminococcaceae NK4A214 group w...