Abstract
This study aimed to determine the effects of Forsythia suspensa extracts (FSE) on performance, antioxidant status, inflammatory cytokines, meat quality, meat fatty acid composition, and gut microbial community in finishing pigs. Sixty-four pigs [Duroc × (Landrace × Yorkshire)] with an average initial body weight of 88.68 kg were randomly allotted to two dietary treatments, with eight replicate pens per treatment (four pens were barrows and four pens were gilts), four pigs per pen. The dietary treatments included a corn-soybean meal basal diet (CON) and an FS diet (basal diet + 100 mg/kg FSE; FS). Compared with CON, pigs fed FSE showed enhanced (P < 0.05) saturated fatty acid (SFA)/polyunsaturated fatty acid (PUFA) ratio, reduced (P < 0.05) lightness, and n-6/n-3 PUFA ratio, as well as tended to increase C20:5n3 content in the longissimus dorsi muscle. Moreover, pigs fed FSE showed decreased (P < 0.05) serum cortisol and tumor nuclear factor-α contents, and increased (P < 0.05) serum high-density lipoprotein cholesterol, superoxide dismutase, and glutathione peroxidase contents compared with CON. These pigs also tended to have increased serum total protein and immunoglobulin G contents, and decreased serum low-density lipoprotein cholesterol and interleukin-1β contents compared with CON. In the colon, pigs fed FSE had a higher (P < 0.05) relative abundance of Bifidobacteriales at the order level, Lactobacillaceae and Bifidobacteriaceae at the family level, as well as Lactobacillus and Bifidobacterium at the genus level compared with CON. In conclusion, dietary Forsythia suspensa extract supplementation effectively improved antioxidant status and anti-inflammatory functions, as well as modulated meat fatty acid composition, and gut microbial community in finishing pigs.