Effect of dietary herbal extract and probiotic supplementation alone or in combination on growth performance, meat quality, and stress indicators of broilers subjected to high stocking density

Objective: Effect of dietary melon-SOD and/or Pediococcus acidilactici on growth performance, meat quality, and stress indicators of broilers subjected to high stocking density (HSD) were investigated in this study. Material and Methods: A total of 504 one-day-old Ross 308 male broiler chicks were randomly distributed to 5 groups, each consisting of 6 replicate pens, each pen measuring 1 m2. Basal diets were formulated. One group was not subjected to HSD, fed diets without supplementation, and served as the control group (12 chicks/m2) whereas the remaining 4 groups were reared at HSD (18 chicks/m2). One of these HSD groups was fed basal diets without any supplementation. Other HSD groups received dietary melon-SOD (12.5 mg/kg), P. acidilactici (100 mg/kg), or a combination of both. Results: Growth performance, meat quality, and H:L ratio were not different among the treatments. Serum SOD activity decreased in HSD group compared to control, melon-SOD, and melon-SOD + P. acidilactici groups (P = 0.046). Birds fed melon-SOD or P. acidilactici alone had lower serum MDA levels than those reared at HSD (P = 0.050). SOD activity in breast meat remained unaffected. However, MDA levels in breast meat were greater in broiler chickens in the HSD group in comparison with other groups (P = 0.009). Conclusion: In this study, melon-SOD and P. acidilactici reduced the HSD-induced oxidative stress in broilers.