Abstract:
The studies were consisting of two experiments. Experiment 1 was employed to determine stocking densities, which caused bird stress. A total of 1,080 day-old, male, Cobb 500 broiler chicks were randomly divided into 3 groups, each with 4 replicates, in closed house under stocking densities of 9, 13 and 18 birds/sq.m. Corn-soybean diet was fed to all treatment groups for 45 days. As density increased, yield of broilers (kg/sq.m.) increased significantly (P<0.05). There were reduction in body weight gain (BWG), European Efficiency Factor (EEF) but increasing in feed conversion ratio (FCR), feed cost per gain 1 kg of broilers, yield of broilers (kg/sq.m.) and income at stocking density of 18 birds/sq.m. As density increased, spleen to body weight ratios, and bursa to body weight ratios had a trend to decrease. Treatment with stocking density 18 birds/sq.m. had a trend to give higher H/L ratios, higher MDA than 9 birds /sq.m. Experiment 2 was conducted to determine the effect of turmeric as an antioxidant on immune status and growth performance of stressed broilers. A total of 2,300 day-old male Cobb 500 broiler chickens were randomly allocated into 5 groups, each with 4 replicates. Birds were reared in closed house under stocking density of 17 birds/m. for 42 days. Group I was fed on corn-soybean basal diet. Group II-IV were fed on basal diets supplementation of turmeric corresponded to 90, 135, and 180 ppm curcuminoid in feed, respectively. Group V was fed on basal diet supplementation with 2.5 ppm avilamycin as an antibiotic growth promoter. The results revealed that supplementing turmeric or avilamycin had a trend to give higher BWG, higher EEF, and lower FCR than the basal diet (P>0.05). Supplementation of turmeric had a trend to show higher feed cost per gain 1 kg. of broilers than those which received basal diet and avilamycin, respectively. In comparison with the basal group, it was found that supplementation of turmeric corresponded to 180 ppm curcuminoid or supplementation of avilamycin had a trend to increase yield of broilers (kg/sq.m.) (P>0.05). Supplementation of turmeric corresponded to 90 and 135 ppm curcuminoid or supplementation of avilamycin reduced H/L ratios at 28 days of age (P<0.05). Moreover, supplementation of turmeric corresponded to 180 ppm curcuminoid reduced H/L ratios at 42 days of age (P<0.05). Supplementation of turmeric corresponded to 90 ppm curcuminoid had a trend to more decrease MDA than avilamycin. Supplementation of turmeric or avilamycin had a trend to increase spleen and bursa to body weight ratios, but had no effect on immune response to titer of Newcastle disease (P>0.05). Supplementation of turmeric corresponded to 180 ppm curcuminoid, had a trend to increase EEF, give higher yield of broilers (kg/sq.m.) than those which received basal diet and avilamycin. It is concluded that increasing stock density had a trend to cause stress in birds. There was an increase in lipid peroxidation in plasma. Thus would suppress immune status or increase lymphoid organ degeneration and had negative effect on broiler performance. Supplementation of turmeric in diet as an antioxidant, could replace antibiotic growth promoter, had a trend to enhance performance and ameliorate immune suppression of stressed broiler.