BACKGROUND: Lead (Pb) induced oxidative stress is known to suppress growth performance in broiler chickens. The current study was carried out in an attempt to describe the specific underlying mechanisms of such phenomenon. OBJECTIVES: The objective of this study was to investigate the effect of Pb-induced oxidative stress on performance, antioxidant status and behavioral responses of broiler chicken. METHODS: Eighty day-old broiler chicks were randomly assigned to 2 dietary treatment groups of 4 pen replicates, namely i) basal diet containing no lead supplement (control) and ii) basal diet containing 200 mg Pb/kg of diet. RESULTS: The results showed that addition of lead decreased body weight gain (p<0.01) and feed conversion ratio (p<0.01). Also, consumption of contaminated diet significantly increased MDA and H/L Ratio and significantly decreased SOD and GPx activity (p<0.01). Moreover, addition of 200 mg/kg diet significantly increased sitting pasture and aggression behavior and decreased feeding behavior (p<0.01).               CONCLUSIONS: Our data conclude that Pb-induced oxidative stress adversely suppressed feed conversion ratio and growth performance. The proposed underlying mechanism for such phenomenon is Pb-induced oxidative stress by impaired antioxidant status and feeding behavior decreased the growth performance.

Objective: Lighting requirements of birds have to be considered for choosing the optimal light intensity. Therefore, the experiment was carried out to study the effects of the different light intensities on performance, welfare and behavior of turkey poults. Materials and Methods: A total of 81 turkey poults aging 3 weeks were randomly selected and divided into three equal groups. The birds were subjected for 3 different light intensities (5, 25 and 50 lux) with 12 h photoperiod in 3 separate rooms. The growth performance parameters of the poults were measured; the parameters were body weight (BW), average feed intake (FI), average body weight gain (ABWG), relative growth rate (RGR), and feed conversion ratio (FCR). Besides, blood parameters and behavioral characters were observed. Results: Our results revealed that poults reared in low intensity (5 lux) had better performance (body weight gain, relative growth rate and feed intake). Also, final body weight was significantly higher in 5 lux. The cortisol level was lower in 5 lux than other 25 and 50 lux. Behavior of poults is affected by light intensities in our study, where feather preening, feather pecking and aggressive behaviors were significantly higher in birds housed in the highest intensity (50 lux). In the same way, drinking time was significantly higher in 25 lux. The poults tended to lay and rest on perches more under the lowest intensity (5 lux). Conclusion: It was concluded that, it is better to use moderate light intensity to improve previous parameters with avoiding abnormal behavior. [J Adv Vet Anim Res 2016; 3(1.000): 18-23]