Performance, slaughter traits and serum corticosterone levels in COBB500 broiler chickens fed lycopene-supplemented diets during heat period

Abstract

Poultry farmers in the tropics suffer great losses in broiler production especially during the post brooding phase as a result of heat stress occasioned by high ambient temperature. This study therefore, investigated the ameliorative effects of synthetic lycopene dietary supplement on growth performance, slaughter traits and serum corticosterone (CORT) levels of COBB500 broiler chickens reared during heat period. A total of 120 birds were selected at 4th week of rearing and allotted into a control group (C) and three experimental groups designated as T1, T2 and T3. Each group had 3 replicates. The four groups were fed the same starter diet for 4 weeks and then differently on finisher diet supplemented with lycopene at 0mg/kg feed (control), 5mg/kg (T1), 10mg/kg (T2), and 15mg/kg (T3) for 3 weeks. Data obtained were analyzed for statistical differences using ANOVA. The results showed that lycopene supplementation increased feed intake significantly (p<0.05) in the birds under groups T1 and T3. Final body weights and weight gain were statistically similar across the groups but numerically improved in the lycopene-supplemented broilers. While the thigh muscle weight increased significantly (p<0.05) across the groups with increasing supplementation, feed conversion ratio (FCR) decreased optimally (2.03) at 15mg/kg supplementation level leading to improved general performance. The supplement also decreased serum CORT concentration significantly (p<0.05) at 5mg/kg level. Therefore, lycopene can be supplemented in diets at 5mg/kg feed as an anti-stress and performance enhancer in COBB500 broiler chickens reared under hot climate.