Effect of a dietary probiotic, Lactobacillus johnsonii BS15, on growth performance, quality traits, antioxidant ability, and nutritional and flavour substances of chicken meat

To determine whether Lactobacillus johnsonii BS15 supplementation improves the growth performance and meat quality of broilers, 450 1-day-old male chicks (Cobb 500) were randomly divided into three groups: control group (basal corn-soybean diet), L-BS15 group (basal diet + 1 x 10(5) colony-forming unit BS15/g as feed), and H-BS15 group (basal diet + 1 x 10(6) colony-forming unit BS15/g as feed). These diets were fed for 42 days. Abdominal fat decreased (P < 0.05) as the concentration of BS15 increased. BS15 supplementation significantly increased the pH at 24 h after sacrifice and decreased drip loss and shearing force (P < 0.05), although meat colour and pH at 40 min after sacrifice remained unchanged. Antioxidant capacity and total protein and intramuscular fat levels were unchanged by the treatments, but BS15 supplementation significantly increased inosine monophosphate level and decreased total cholesterol and triglyceride levels (P < 0.05). The levels of proline, total amino acids, and flavour-related amino acids were increased (P < 0.05) by BS15 supplementation, but the levels of other amino acids did not change significantly. BS15 supplementation significantly decreased (P < 0.05) C16:0, C22:4n-6, and n-6 : n-3 ratio and increased (P < 0.05) C18:3n-3, C20:5n-3, C22:6n-3, total polyunsaturated fatty acid (PUFA), n-3 PUFA and PUFA : saturated fatty acid ratio. These findings suggest that L. johnsonii BS15 supplementation improves the meat quality of broilers by increasing the shelf life and flavour and nutritional substances. In addition, BS15 supplementation can induce changes in fat deposits and fatty acid composition.