Effects of sweet potato vine silage supplementation on growth performance, nutrient digestibility, and intestinal health in finishing pigs

We investigated the effects of sweet potato vine silage (SPVS) supplementation on the growth performance, apparent digestibility and gut health of finishing pigs. 180 Bali Black pigs (Berkshire × Licha Black, with body weight of 74.54 ± 3.32 kg) were assigned to three groups: basal diet (Ctrl), Ctrl supplemented with 2.5% SPVS (Lspvs) and 5.0% SPVS (Hspvs). Animals were slaughtered after nine weeks of feeding. The results indicated that dietary SPVS supplementation improved average daily food intake and average daily gain. However, SPVS treatment decreased the apparent digestibility. Activities of antioxidant enzymes including total superoxide dismutase, total antioxidant capacity, glutathione peroxidase and catalase in the intestines of the Lspvs group were markedly upregulated. Concentrations of IL-1β and IL-6 were decreased and secretory immunoglobulin A was increased in Lspvs group. A significant increase (P < 0.05) of ileum diamine oxidase in Lspvs group was observed. The ileum villus height/crypt depth in the Hspvs group was significantly reduced. The ratio of Firmicutes to Bacteroidetes in the caecum contents of pigs was reduced, and the abundance of Lactobacillus was significantly increased. Specifically, Hspvs treatment markedly reduced the abundances of Proteobacteria. Collectively, these results suggest that dietary supplementation with SPVS is capable of improving growth performance, immune function and intestinal health by promoting the balance of the intestinal microbiota.