A. Vinoth, T. Thirunalasundari, M. Shanmugam and U. Rajkumar
The present study was aimed at finding the effects of early age thermal conditioning on liver HSP 90 alpha, 70 and 60 mRNA expression and plasma biochemical parameters in colored broiler chicken. Chicks from two breeds (Naked neck and Punjab Broiler-2) were divided in to control (C) and heat exposed (H). The chicks were reared in controlled environmental chamber (25±1°C). H group chicks were exposed to 43±1º C for 6 hours during 5-7th day post hatch. Chicks from H group and a sample of chicks from control group (CE) were exposed to 43±1°C for 6 hours on 42nd day. On 7th and 42nd day chicks from each group were sacrificed for sample collection and processing. On 7th day the mRNA expression of all the three genes were significantly (P<0.05) higher in H group in both the breeds. On 42nd day CE group chicks had significantly (P<0.05) higher mRNA expression for all HSP genes compared to HE birds. T3 concentration was significantly (P<0.05) higher in H group birds in both the breeds at 7th day. The biochemical parameters significantly (P<0.05) varied between the C and H groups at 7th day. The biochemical parameters were significantly lower (P<0.05) in HE group birds compared to CE group birds after acute heat exposure on 42nd day. Based on the results of this study it can be concluded that early age thermal conditioning of chicks improves the thermo tolerance in post natal life in colored broiler chicken.
