Effect of dietary supplemental wheat starch by-product on growth performance, carcass Traits and immune responses of broiler chickens.

Abstract

This experiment was conducted to investigate effects of a wheat starch by-product (WSB) on growth performance, carcass traits and immune responses of broiler chickens. A total of 300 one-day old broiler chicks (Ross 308) were assigned to 5 dietary treatments and 5 replicates in a completely randomized design during 9 to 16, 17 to 25, 26 to 39, and 40 to 50 days of experiment. Dietary treatments included a basal diet without WSB supplementation (CTL) or graded levels of low (LSS; 100, 150, 200, and 250 g/kg), medium (MSS; 200, 250, 300, 350 g/kg), high (HSS; 300, 350, 400, 450 g/kg) and extra (ESS; 400, 450 500, and 550 g/kg) inclusion rates of wheat starch during the starter, growing, finisher 1, and finisher 2 periods, respectively. Dietary supplementation of WSB did not have adverse effect on growth and feed conversion ratio of broiler chickens across 9 to 25 days of age but compromised growth performance during finisher and the entire rearing periods ( P ˂ 0.05). Feeding diets containing WSB decreased carcass yield in broiler chickens ( P ˂ 0.05). Antibody titer against Newcastle disease virus decreased following dietary HSS and ESS supplementation ( P ˂ 0.05). Moreover, supplementation of LSS and ESS to the feed decreased relative weight of spleen ( P ˂ 0.05). In conclusion, dietary supplementation of WSB is recommended up to 450 g/kg across 9 to 25 days of age without any adverse effect on growth performance of broiler chickens. However, supplementation of WSB may impair immune responses of broiler chickens.