Studies on the juvenile body weights and some heat stress parameters in three genetic groups of synthetic coloured broilers exposed to heat stress during 4-6 weeks in growth chambers

Reddy, B.L.N., Rajkumar, U. and Prince, L.L.L. 2020. Studies on the juvenile body weights and some heat stress parameters in three genetic groups of synthetic coloured broilers exposed to heat stress during 4-6 weeks in growth chambers. Indian Journal of Poultry Science, 55(3): 179-182.

An experiment was conducted utilizing the three genetic groups: coloured synthetic broiler male line (G1), Naked neck broiler line (G2) and cross of these two broiler lines (G3) to evaluate heat stress in those birds. Eight replicates with five birds per replicate thus total forty birds were kept in each genetic group. Two treatments (control and heat treated group) were maintained in each genetic group and reared in battery brooders. Heat treated group birds were subjected to heat stress during 4-6 weeks of age in growth chambers maintained at 40°C and 70% R.H. at three hours of exposure per day. Juvenile body weights were recorded at 0 day, 2, 4, 5, 6 and 7 weeks of age. Blood samples (2ml) were collected from one bird of each replicate and serum was separated and heat stress parameters viz., lipid peroxidise, glutathione peroxidase, superoxide dismutase, alkaline phosphatase and RBC catalase were estimated. 3 × 2 factorial general linear model was used to analyse data. It was found that juvenile body weights at 5, 6 and 7 weeks were significantly decreased in all genetic groups subjected to heat stress. Genotype × Treatment interactions were non-significant for all the genetic groups. Lipid peroxidase estimates were significantly different between the treatment groups. Glutathione peroxidase estimates were significantly different in Genotype × Treatment interaction and superoxide dismutase was significantly different between the genetic groups. It was concluded that, naked neck birds (G2) and cross of Naked neck (G3) were more resistant to heat stress as compared to normal feathered birds (G1).