Probiotic Effects on Behavior, Stress Indicators and Antioxidant Activity of Transported Broiler Chicken

Transportation before slaughtering causes bad effects on chicken welfare and health, but little is known about the effect of probiotic dietary fed in broiler chickens having transport stress. So, this study was designed to detect the effects of two doses of a probiotic (Bacillus subtilis) on some stress indicators, antioxidant activity and fear response of broiler chickens exposed to transportation stress. Two hundred and ten broiler chicks were distributed among 21 floor pens (10 chicks in each pen), each pen was exposed to one of three diet treatments containing a probiotic at 0 (control), 0.25 (0.25X), and 0.5 (0.5X) g/kg. At 35 days old, birds were exposed to transportation and then blood samples were collected for measuring stress and antioxidant markers. The serum corticosterone and cholesterol levels were decreased in probiotic fed birds in comparison with controls (P < 0.05). Compared to control broiler chickens, 0.5X birds had higher levels of catalase and serum superoxide dismutase (P < 0.05). In addition, the 0.5X birds spent less time in the tonic immobility test (P = 0.0427). The results suggest that the probiotic supplement may prove to be an important management tool for the broiler industry to diminish the negative effects of transport stress, potentially safeguarding the welfare and health of broiler chickens.