RESUMEN
BACKGROUND AND OBJECTIVE: Inclusion of vitamin E in poultry diets and manipulation of temperature at early age has been known to help birds cope with heat stress at later age of their life. This study was conducted to investigate the effects of early age heat conditioning (EHC) and vitamin E addition on the performance and blood parameters to alleviate deleterious impact of heat stress in quail chicks. MATERIAL AND METHODS: Three hundred one-day-old quail chicks were randomly divided into 4 groups of 5 replicates with 15 birds of each. Treatments were: Control, vitamin E: Chicks were fed the basal diet supplemented with 200 IU kg-1 diet vitamin E, EHC: Chicks were exposed to 40±1°C for 2 h at days 7th and 13th of embryogenesis and EHC+vitamin E: Chicks were exposed to 40±1°C for 2 h at days 7th and 13th of embryogenesis and fed the basal diet supplemented with 200 IU kg-1 vitamin E. The experiment lasted from 1-40 days of age. RESULTS: The results indicated that using early age heat conditioning and/or supplementation of vitamin E significantly (p<0.05) improved body weight, feed intake and feed conversion ratio at 40 days of age. Significantly (p<0.05) improvement was observed in blood pH, H/L ratio and Hb concentration, thyroid hormones (T3 and T4), plasma protein fractions and antioxidant status (Total antioxidant capacity, catalase and superoxide dismutase). CONCLUSION: Exposed quail chicks to early age heat conditioning and addition of vitamin E at 200 IU kg-1 diet can effectively alleviate the adverse effects of heat stress.