Effect of Bacillus subtilis Natto on Meat Quality and Skatole Content in TOPIGS Pigs

This study investigated the effect of Bacillus subtilis (B. subtilis) natto on meat quality and skatole in TOPIGS pigs. Sixty TOPIGS pigs were randomly assigned to 3 groups (including 5 pens per group, with 4 pigs in each pen) and fed with basic diet (control group), basic diet plus 0.1% B. subtilis natto (B group), and basic diet plus 0.1% B. subtilis natto plus 0.1% B. coagulans (BB group), respectively. All pigs were sacrificed at 100 kg. Growth performance, meat quality, serum parameters and oxidation status in the three groups were assessed and compared. Most parameters regarding growth performance and meat quality were not significantly different among the three groups. However, compared with the control group, meat $pH_{24}$, fat and feces skatole and the content of Escherichia coli (E. Coli), Clostridium, $NH_3$-N were significantly reduced in the B and BB groups, while serum total cholesterol, high density lipoprotein, the levels of liver P450, CYP2A6, and CYP2E1, total antioxidant capability (T-AOC) and glutathione peroxidase and Lactobacilli in feces were significantly increased in the B and BB groups. Further, the combined supplementation of B. subtilis natto and B. coagulans showed more significant effects on the parameters above compared with B. subtilis, and Clostridium, and $NH_3$-N. Our results indicate that the supplementation of pig feed with B. subtilis natto significantly improves meat quality and flavor, while its combination with B. coagulans enhanced these effects.