Dietary supplementation with flavonoids from mulberry leaves improves growth performance and meat quality, and alters lipid metabolism of skeletal muscle in a Chinese Hybrid Pig

The effect of dietary supplementation of flavonoids from mulberry leaves (FML) on the growth, carcass traits, meat quality, serum antioxidative parameters, and fatty acid profile and lipid metabolism of skeletal muscle in finishing pigs were investigated in the present study. A total of 120 crossbred F1 barrows of Berkshire and Bama mini-pig with an average initial body weight (BW) of 45.11 ± 4.23 kg were randomly assigned to one of five treatment groups. Each treatment group consisted of six replicates (pens) with four pigs per pen. The pigs were fed either a control diet (FML0) based on corn, soybean meal, and wheat bran, or the control diet with 200, 400, 800, or 1600 mg/kg of added FML (treatments FML200, FML400, FML800, FML1600, respectively). The feeding experiment lasted for 58 days after a 7-day adaptation period. Blood and muscle samples were collected from 30 pigs (one pig per pen) at the end of this experiment. The results showed that FML increased (P < 0.05) the average daily gain, lean meat percentage, loin-eye area, and contents of C10:0, C18:3n3, and n-3 polyunsaturated fatty acid (PUFA) in the longissimus lumborum (LL) muscle, and serum activities of superoxide dismutase and catalase in a significant linear or quadratic pattern. FML reduced (P < 0.05) the ratio of feed intake to body weight gain, body fat percentage, muscular ratio of ∑n-6 PUFA/∑n-3 PUFA, and serum malondialdehyde concentration. The reduction in the fiber cross-sectional area and shear force in LL of finishing pigs was observed in the FML inclusion groups. Furthermore, the mRNA expression levels of PPARγ-LXRα-ABCA1 pathway genes and related protein abundance in LL were modulated by FML administration. These results indicate that dietary FML supplementation < 1600 mg/kg improved growth performance and meat quality, and regulated lipid metabolism of finishing pigs.