Effects of Dietary Tongmai Granule Residue Supplementation on Growth Performance, Nutrient Digestibility, Blood Biochemical Parameters and Rumen Fermentation in Sheep

Abstract The purpose of this study was to investigate the effects of Tongmai granule residue (TGR) on the growth performance, apparent nutrient digestibility, blood biochemical parameters, and rumen fermentation in Doper x Small Tail Han hybrid sheep. Twenty-four healthy female lambs (6–7 months of age; 29.64 ± 1.80 kg initial body weight) were randomly divided into 3 groups and fed for 75 days. The control group was fed a commercial concentrate and the other groups were fed diets supplemented with 10% and 15% TGR respectively. Dietary 15% TGR supplementation decreased average daily gain, apparent digestibility of neutral detergent fiber, but increased the feed conversion ratio, apparent digestibility of crude fat and organic matter in lambs (P < 0.05). The 10% TGR group significantly increased the apparent digestibility of organic matter (P < 0.05). Dietary supplementation of 10% and 15% TGR significantly increased serum high density lipoprotein cholesterol (HDL-C) content on day 15, IgG content on day 30, and IgA content on day 60 of the feeding period (P < 0.05). Dietary supplementation of 15% TGR significantly increased the content of IgA on the 30th day (P < 0.05), and significantly decreased blood urea nitrogen (BUN) on the 30th day (P < 0.05) of the feeding period. TGR at 15% significantly decreased the contents of acetic acid, propionic acid, butyric acid, and total volatile fatty acids (TVFA) in the rumen (P < 0.05), and significantly increased the pH, NH3-N concentration, and acetic acid: propionic acid ratio (P < 0.05). The results suggest that, the addition of TGR to diet can improve the apparent digestibility of crude fat and organic matter, and improve the anti-atherosclerosis ability and immune function of Doper x Small Tail Han hybrid female lambs. The dietary addition of 10% TGR yielded the best feeding effect in this experiment.