Dietary taurine supplementation ameliorates muscle loss in chronic heat stressed broilers via suppressing the perk signaling and reversing endoplasmic reticulum-stress-induced apoptosis.

BACKGROUND Heat stress seriously affects animal health and induces enormous financial losses in poultry production. Exploring the appropriate means is essential for ameliorating unfavorable effects caused by heat stress. We explored whether the taurine supplementation could attenuate breast muscle loss in chronic heat-stressed broilers and its mechanism. We designed three groups: the normal control group (NC, 22°C), heat stress group (HS, 32°C) and taurine treatment group (THS, 32°C, basal diet + 5g·kg-1 taurine). RESULTS We found that taurine significantly moderated the decreases of breast muscle mass and yield, and the increases of serum aspartate aminotransferase activity and serum urine acid level in chronic heat-stressed broilers. Additionally, supplementary taurine significantly alleviated the elevation of cytoplasm Ca2+ concentration, the protein expressions of GRP78 and p-PERK, the mRNA expressions of Ca2+ channels (RyR1, IP3R3) and endoplasmic reticulum (ER) stress factors (GRP78, GRP94, PERK, EIF2α, ATF4, IRE1, XBP1, ATF6, and CHOP), apoptosis (Caspase-3, and TUNEL), protein catabolism, and the reduction of taurine transporter (TauT) in breast muscle induced by chronic heat stress. CONCLUSION Supplementary taurine could attenuate chronic heat stress-induced breast muscle loss via reversing ER stress-induced apoptosis and suppressing protein catabolism. This article is protected by copyright. All rights reserved.