Effect of fermented corn-soybean meal on carcass and meat quality of grower-finisher pigs.

The fermented feed has been identified as a potential alternative to antibiotics in feeds that markedly affects gut health and growth performance of pigs. Two recent studies performed in our laboratory investigated that the fermented corn-soybean meal (fermented feed, FF) improved the gut health of pigs. This study was conducted to determine the effect of a FF on the carcass, meat quality, muscle fatty acids profile, muscle amino acid and antioxidant ability of grower-finisher pigs. In this study, a total of 48 crossbred barrows (Duroc × Landrace × Large White) were randomly divided into 2 treatments with unfermented corn-soybean diet (Ctrl) and FF diet. Compared with control pigs fed a standard diet, the results showed that FF significantly increased the muscle colour of redness and significantly reduced muscle moisture loss rate. Furthermore, FF significantly increased the content of aromatic amino acids such as aspartic acid, glutamic acid and alanine. More importantly, FF increased monounsaturated fatty acid and polyunsaturated fatty acid content. Collectively, FF could be a promising feed strategy in improving meat quality and nutritional value in grower-finisher pig.

Effect of Fermented Corn-Soybean Meal on Serum Immunity, the Expression of Genes Related to Gut Immunity, Gut Microbiota, and Bacterial Metabolites in Grower-Finisher Pigs.

Fermented corn-soybean meal (fermented feed, FF) is commonly used in swine production, but the effects of FF on gut health remain unclear. In this study, serum immunity, mRNA abundances of antimicrobial peptides (AMPs) and Toll-like receptors (TLR1-9), bacterial abundance in the duodenum and colon, and colonic metabolic phenotypes were determined in crossbred barrows (Duroc × Landrace × Large White) fed FF or normal feed (unfermented feed, UF) (n = 6). When compared to the UF group, the results showed that serum levels of IgG and IgM were significantly increased in FF group pigs (P < 0.05). FF significantly decreased the abundances of Bacteroides and Verrucomicrobia in the duodenum and decreased the abundances of Bacteroides, Proteobacteria, and Verrucomicrobia in the colon while it significantly increased the abundances of Firmicutes and Actinobacteria (P < 0.05). Furthermore, a Spearman's correlation analysis showed that serum immunity and the expression of genes related to gut immunity were associated with bacterial strains at the family level. Moreover, differentially abundant colonic microbiota were associated with colonic metabolites. LC-MS data analyses identified a total of 1,351 metabolites that markedly differed between the UF and FF groups. C5-Branched dibasic acid metabolism was significantly upregulated whereas the purine metabolism was significantly downregulated (P < 0.05) in the colonic digesta of pigs in the FF meal group compared to the UF meal group. Collectively, these results indicated that FF meal could influence serum immunity and the expression of genes related to gut immunity, correlating with the gut microbiota and bacterial metabolites in grower-finisher pigs. This study may provide an alternative strategy for improving the intestinal health of grower-finisher pigs.

Fermented corn-soybean meal elevated IGF1 levels in grower-finisher pigs.

Fermentation has attracted increasing attention in pig industry, because of low costs and numerous benefits on pig growth and health as well as environmental improvement, although the mechanisms remain largely unknown. In the present study, fermented corn-soybean meal significantly improved average daily gain and gain:food ratio (P < 0.05). Fermented feed (FF) significantly increased insulin-like growth factor 1 (IGF1) transcription in liver (P < 0.05). Meanwhile, fermented meal significantly enhanced the binding of CCAAT/enhancer-binding protein beta (C/EBPß) to IGF1 promoter and C/EBPß expression in liver (both P < 0.05). FF tended to increase IGF1 proteins in liver and serum too (both 0.05 < P < 0.10). Meanwhile, FF slightly but significantly increased hepatic and circulating triglyceride and total cholesterol levels, as well as serum ratio of high-density to low-density cholesterol (all P < 0.05). Our data indicated that FF could significantly augment the binding of C/EBPß to IGF1 promoter and promote hepatic IGF1 expression and production, thus boost pig growth.