Fermented Broccoli Residue Reduced Harmful Bacterial Loads and Improved Meat Antioxidation of Free-Range Broilers

Abstract

Free-range animals with unavoidable exposure to dirt and dung easily carry harmful bacteria, but little is known about the effect of dietary fermented supplement on bacterial loads. This study investigated the effect of fermented broccoli residue (FB) on the growth performance, harmful bacterial loads, and meat antioxidation of free-range broilers from 42 to 84 d of age. Six free-range pens (n = 40 chickens per pen) were randomly assigned to 1 of 3 treatments containing FB at 0 (control), 5, or 10%. The results showed that the 2 levels of FB did not affect growth performance, but decreased (P < 0.01) mortality. In cecal digesta, compared with the control, FB added at 10% decreased (P < 0.05) Salmonella, Campylobacter, Clostridium perfringens (C. perfringens), Escherichia coli (E. coli), and Gram-negative bacteria (Gram–), and FB added at 5% decreased (P < 0.05) Campylobacter, E. coli, and Gram–. On neck skin, the 2 levels of FB decreased (P < 0.01) Campylobacter, E. coli, and Gram–. In pectoralis major muscle, compared with the control, the 2 levels of FB increased (P < 0.01) the activities of superoxide dismutase (SOD), glutathione peroxidase, total antioxidant capacity, and catalase, and in gastrocnemius muscle similar FB effects were found on these parameters except for catalase. In contrast, the high FB treatment showed a more pronounced effect (P < 0.05) on SOD in the 2 muscles. The results suggest that dietary FB can be used to reduce harmful bacterial loads and improve meat antioxidation of free-range broilers.