Abstract
Total of 120 Cobb 500 chicks and 120 Ross 308 chicks were allotted randomly into three treatments; hot pepper in ration 2%, hot pepper in water 1% and control group (40 bird per group) from 2 to 6 weeks consecutively to investigate the effect of hot pepper supplementation in ration or water on productive performance, carcass traits and immune response of different broiler breeds.
The obtained results revealed that hot pepper supplementation in water 1% or ration 2% improved body weight, weight gain and feed conversion ratio of broilers compared to control group at the early ages (21 day) with significant (P˂0.05) increment in body weight for 1% hot pepper water supplemented group compared to control. Moreover, immune response to NDV improved by hot pepper supplementation in water or diet enhanced while, immune response to IBD improved only by water supplementation by hot pepper. Water supplementation with hot pepper 1% significantly (P˂0.05) increased dressing percentage compared to other groups although hot pepper supplementation had no effect on carcass traits or internal organs weight.
Ross 308 had significant higher body weight and weight gain (P˂0.01) compared to Cobb 500. Feed conversion ratio and water intake did not affected by breeds or addition of hot pepper. Mortality % was higher in Cobb 500 than Ross 308, also Ross 308 responded better to hot pepper water 1% during early ages however Cobb 500 response was better during late ages.
It could be concluded that water supplementation with hot pepper 1% achieved better effects on productive performance, mortality % and immune response to NDV and IBD of broiler than hot pepper ration supplementation 2%, also use of hot pepper at early ages better than whole growth period.

Key words: Hot pepper, Performance, Ross 308, Cobb 500, Carcass traits, NDV, IBD