Effects of Moderately Reduced Dietary Net Energy on Growth Performance, Meat Quality and Intestinal Barrier Function in Growing Pigs

This study assessed the impacts of dietary net energy (NE) levels on growth performance, meat quality and intestinal health in Tunchang Black pigs. Forty-eight pigs with an initial body weight of 11 kg were allocated into four groups and fed diets containing 10.65 (N1), 10.15 (N2, control), 9.65 (N3) and 9.15 (N4) MJ/kg NE respectively over a 42-day experimental period. The N4 group presented lower average daily gain and carcass weight relative to the N1 group, while no significant differences in growth performance were detected between N2 and N3. The N3 group displayed superior meat quality characteristics, manifested as decreased contents of saturated fatty acids (C10:0, C12:0), elevated selenium concentration, upregulated expression of slow-twitch myosin heavy chain (MyHC I) and downregulated expression of fast-twitch MyHC IIb, alongside increased ileal occludin expression. Moreover, the N3 treatment improved antioxidant capacity, as reflected by higher serum GSH and SOD levels and lower serum MDA content. In conclusion, decreasing dietary NE from 10.15 to 9.65 MJ/kg exerted no detrimental influence on growth performance yet effectively ameliorated meat quality, antioxidant status and intestinal barrier function in Tunchang Black pigs.