Supplemental effects of probiotic Bacillus subtilis fmbJ on growth performance, antioxidant capacity, and meat quality of broiler chickens

This study aimed to investigate the supplemental effects of probiotic Bacillus subtilis fmbJ (BS fmbJ) on growth performance, antioxidant capacity, and meat quality of broiler chickens. A total of 240 day-old male Arbor Acres (AA) broiler chickens were randomly allotted to 4 treatments and raised for 6 wk. Each treatment had 6 replicate pens with ten birds per replicate. Birds in the control group (CON) were fed diets without BS fmbJ and antibiotics. The BS groups were fed the basal diets with BS fmbJ at 2 × 10¹⁰ cfu/kg (BS-1 group), BS fmbJ at 3 × 10¹⁰ cfu/kg (BS-2 group), BS fmbJ at 4 × 10¹⁰ cfu/kg (BS-3 group) without antibiotics for 42 d. In the study, dietary supplementation with BS fmbJ significantly improved (P < 0.05) the average daily gain (ADG), average daily feed intake (ADFI), and feed conversion ratio (FCR) of broilers from 21 to 42 d and 1 to 42 d. At 42 d, the final body weight was increased (P < 0.05) in BS-2 group compared with that in CON. Dietary BS fmbJ significantly increased (P < 0.05) serum IgA and IgG concentrations of broilers after 42 days raising. The glutathione (GSH), glutathione reductase (GR), glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) activity of serum and liver were increased (P < 0.05), and methane dicarboxylic aldehyde (MDA) contents in serum and liver were decreased (P < 0.05) by BS fmbJ added into the broiler diets. Dietary supplementation with BS fmbJ significantly decreased (P < 0.05) reactive oxygen species (ROS) contents in liver mitochondria of broilers. Additionally, the expression of antioxidant enzyme gene including nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase 1 (HO-1), superoxide dismutase (SOD), and glutathione peroxidase (GPx) were improved (P < 0.05) by BS fmbJ added into the broiler diets. Among measuring items of chicken breast meat quality, the drip loss, cooking loss, shear force, L*_{24 h}, a*_{24 h,} b*_{45 min,} and b*_{24 h} values were influenced (P < 0.05) by BS fmbJ provided in the diet. Based on these results, Bacillus subtilis fmbJ could be acted as a beneficial feed additive with antioxidant capacity in broiler diets.