Dietary supplementation of polyphenols alleviates the negative effects of heat stress in broilers

Biological experiment was carried out with 240 chicks to study the effect of polyphenols on heat stress (HS) alleviation under different cereal sources in 2 x 3 factorial study. Six experimental groups consisted of two cereal groups (conventional and alternate cereals). Conventional has corn as sole cereal source, whereas in alternate group broken rice and sorghum were used. Each category was supplemented with 0, 50 and 100 ppm of polyphenols from pomegranate peel extract (PPE). Birds fed rice-sorghum diet with or without PPE had numerically higher values than corn counterpart. Cereal sources had a significant effect on core and comb temperature, as well as the respiration rate. HL ratio of birds exposed to HSwas altered significantly by dietary changes as well as the PPE supplementation. Birds fed with PPE had lower HL ratio than control groups. The mRNA expression level of HSP70 in the jejunum was significantly up-regulated in groups supplemented with PPP at 50 and 100 ppm in both types of cereal sources. There was higher serum HSP70 protein 1A in supplemented groups than their respective unsupplemented cereal groups. Supplementation of polyphenols as pomegranate peel extract at 50 ppm improved HSindicators, performance and antioxidant status with major activity in alternate cereal source (broken-rice-sorghum).