Fermented mixed feed alters growth performance, carcass traits, meat quality and muscle fatty acid and amino acid profiles in finishing pigs

This study was conducted to investigate the effects of fermented mixed feed (FMF) on growth performance, carcass traits, meat quality, muscle amino acid and fatty acid composition and mRNA expression levels of genes related to lipid metabolism in finishing pigs. In the present study, 144 finishing pigs (Duroc × Berkshire × Jiaxing Black) were randomly allocated to 3 dietary treatments with 4 replicate pens per group and 12 pigs per pen. The dietary treatments included a basal diet (CON), a basal diet + 5% FMF and a basal diet + 10% FMF. The experiment lasted 38 d after 4 d of acclimation. The results showed that 5% and 10% FMF significantly increased the average daily gain (ADG) of the females but not the males (P < 0.05), but FMF supplementation showed no impact on carcass traits. Moreover, 10% FMF supplementation increased the meat color45 min and meat color24 h values, while it decreased the shear force relative to CON (P < 0.05). In addition, 10% FMF significantly increased the contents of flavor amino acids (FAA), total essential AA (EAA), total non-EAA (NEAA) and total AA relative to CON (P < 0.05). Furthermore, the diet supplemented with 10% FMF significantly increased the concentration of n-3 polyunsaturated fatty acids (PUFA), n-6 PUFA and total PUFA, and the PUFA to saturated fatty acids ratio (P < 0.05), suggesting that FMF supplementation increased meat quality. Moreover, compared with the CON, 10% FMF supplementation increased the mRNA expression of lipogenic genes, including CEBPα, PPARγ, SREBP1 and FABP4, and upregulated the expression of unsaturated fatty acid synthesis (ACAA1 and FADS2). Together, our results suggest that 10% FMF dietary supplementation improved the female pigs' growth performance, improved the meat quality and altered the profiles of muscle fatty acids and amino acids in finishing pigs. This study provides a reference for the production of high-quality pork.