The effects of dietary vitamin C and Citrus Sinensis peel ongrowth, hematological characteristics, immune competence, andcarcass characteristics in broilers exposed to heat stress

This study investigated the role of vitamin C and Citrus Sinensis peel (sweet orange peel (Sop)) on growth, carcasscharacteristics and health status in 160 one day old broiler chickens (Ross308) which were randomly divided into four equalgroups consisting 4 pens. Each pen having 10 birds (5 male and 5 female) for 35 days. All chicks were exposed to heat stress(33°C) during all the experimental period (35 days). Group one considered as control, groups 2, 3, 4 were given feedcontaining vitamin C (500ppm/ feed), sweet orange peel (Sop) (1,2 % respectively). Sop 2% significantly increased averagebody weight gain and feed intake during the grower period (16-28) (P 0.05). The birds fed Sop 2% during the wholeexperimental period had higher FI and greater feed conversion ratio (P 0.05) compared to the other groups. The mortality ratetended to be the lowest in the birds fed the feed additives (P 0.05). The relative weight of internal organs, blood profilespictures were not affected by Sop with two tested levels (P 0.05) or vitamin C compared with the control group. Broiler fedvitamin C or Sop levels had greater primary and secondary antibody responses to sheep red blood cells (SRBC) and againstphytohemagglutinin (PHA-P) antigen compared with those in the control group (P 0.05). Sop and vitamin C increasedantibodies titer against Newcastle disease during the secondary antibody response (P 0.05). Overall, Sop as feed additiveimproved immune responses in broiler chickens under heat stress. Also the result indicate that the Sop 2 % during the growerperiod had a positive effect on growth performance of broiler chickens under heat stress.