Objective: This study investigated the effects of chemically protected sodium butyrate (CSB) on growth performance, serum indicators, rumen fermentation parameters, and microbial communities in Gangba sheep.Methods: Twenty-four healthy 5-month-old male Gangba sheep with an initial body weight of 19.54±1.04 kg were randomly assigned to four groups and fed diets containing 0, 1.0, 5.0, and 10.0 g/kg CSB for 74 days. After a 14-day adaptation period, the daily feed intake of Gangba sheep was measured. Fecal samples were collected during the last 7 days of the trial, and serum and rumen fluid were sampled on the final day.Results: CSB improved final body weight, average daily dry matter intake, and average daily gain while reducing the feed conversion ratio of Gangba sheep (p<0.05). In addition, CSB improved the apparent digestibility of crude protein, dry matter, and neutral detergent fiber (p<0.05). Furthermore, CSB increased serum immunoglobulin G levels while decreasing tumor necrosis factor-α levels (p<0.05). Meanwhile, CSB increased serum growth hormone-releasing hormone levels (p<0.05). Furthermore, CSB increased rumen fluid pH and concentrations of ammonia nitrogen, acetic acid, iso-butyric acid, butyric acid, and total volatile fatty acids, as well as activities of lipase and butyrate kinase (p<0.05). Besides, CSB enhanced the rumen microbiota structure by increasing the relative abundance of Fibrobacter, unclassified Oscillospiraceae, and Ruminococcus.Conclusion: CSB improved immunological and hormone indicators, enhanced the rumen ecological environment, and increased feed digestibility and utilization, thereby promoting the growth of Gangba sheep. It is recommended to use a dosage of 5.0 g/kg dry matter for optimal growth performance and health benefits.

The study’s objectives were three-fold. Firstly, the impacts of three advanced harvest times (10 days, 5 days, 0 days) on the nutrient composition of peanut vine (PV) were investigated to determine the optimal harvesting time for peanut vine; secondly, the chemical composition and fermentation characteristics of silage produced by combining peanut vine with either wheat bran (PV-WB silage) or corn meal (PV-CM silage) with adding different inoculants (named as TTX, DBN, and JNK) were evaluated; finally, the post-ensilage microbial community was analyzed to assess the effects of inoculants and silage substrates on the bacterial and fungal communities, as well as their interactions. The results indicated that harvesting peanut vine 5 days early significantly enhanced the retention of crude protein and reduced the content of acid detergent fiber and acid detergent lignin compared to harvesting at 0 days (p < 0.05). PV-WB silage exhibited higher crude protein content than PV-CM silage, irrespective of the inoculant used (p < 0.05). The application of the TTX inoculant notably reduced the acid detergent lignin content and enhanced the potential biodegradation, while also increasing the concentrations of acetic acid and lactic acid (p < 0.05). The bacterial community was predominantly composed of the genera Lactobacillus, Pediococcus, and Weissella; however, a greater abundance of Enterobacter and Enterococcus was obtained in the control (CON) treatment. The use of the JNK inoculant resulted in a Saccharomyces abundance exceeding 89%, which led to elevated levels of ammonia-N and higher pH values. In summary, the advanced 5 days to harvest peanut vines retained more crude protein content and decreased the acid detergent fiber and acid detergent lignin content. Fresh peanut vines co-silage with WB including TTX inoculant improved the peanut value nutrient preservation and fermentation parameters.