Nutritional strategies to alleviate heat stress effects through feed restrictions and feed additives (vitamins and minerals) in broilers under summer conditions

ABSTRACT

This experiment was aimed to determine the beststrategies for alleviating the detrimental effects of heat stressby feed restriction (FR) in hot times and dietarysupplementation with Vit.+Min. (vitamins and minerals) bytheir impacts on growth parameters, mortality rate, serumbiochemistry indices and carcass traits of broiler undersummer conditions in the open-sided house. A total of 420broilers of Ross 308 (unsexed 7-day-old) were equally dividedinto 7 treatments (T). Throughout the experiment, chicks in T1(control) fed ad libitum on basal diets, FR was applied in T2,T3 and T4 as followed 2, 3, 4 hours (h) without feedingrespectively. Supplemental vitamin C (Vit.C) + vitamin E(Vit.E) + chromium (Cr) + zinc (Zn) as followed100+100+0.5+50 (T5), 150+150+1.0+75 (T6),200+200+1.5+100 (T7) mg/kg diet respectively. It was foundthat FR and feed additives improved body weight, weightgain, and significantly decreased feed conversion, mortalityrate, and abdominal fat of stressed broiler. Applying FR (3, 4h) and supplementation with Vit.+Min. (T6, T7) significantlyincreased total serum protein and statically decreased totalserum cholesterol. Overall results conducted that FR for 3 h(T3) and dietary supplementation (T7) have the mostsignificant results which indicate the vital role of FR andsupplementation with Vit.+Min. in stressed broilers.(AU)