Resveratrol Alleviates Heat Stress-Induced Impairment Of Intestinal Morphology, Barrier Integrity And Inflammation In Yellow-Feather Broilers

Context: Heat stress is one of the problems commonly found in broiler industry in tropic and subtropic regions that results in impairment of intestinal integrity, leading to inflammation and poor performance.Aims: This study aimed to investigate the effect of dietary resveratrol supplementation on growth performance, intestinal morphology and barrier integrity, and inflammation response of yellow-feather broilers under heat stress.Methods: In total, 288 birds (28-day-old) were randomly allotted to three treatment groups, with six replicates. A thermo-neutral group (24 +/- 2 degrees C) received a basal diet and two heat-stressed groups (37 +/- 2 degrees C for 8 h/day and 24 +/- 2 degrees C for the remaining time) were fed the basal diet (HT) or basal diet supplemented with 500 mg/kg resveratrol for 14 consecutive days.Key results: Compared with the thermo-neutral group, birds in the HT group had a decreased (P < 0.05) average daily feed intake, average daily gain, villus height, villus height to crypt depth ratio, mRNA concentrations of mucin-2, secreted immunoglobulin A (sIgA), claudin-1,zona occludens-1 and serum concentrations of interferon gamma, and increased (P < 0.05) feed to gain ratio, crypt depth, mRNA levels of expression of heat-shock protein (HSP) 70, HSP90, nuclear factor kappa B, mucin-4, claudin-2 and serum concentrations of endotoxin, interleukin (IL)-1 beta, IL-4, IL-6 and tumour necrosis factor (TNF)-alpha on Day 3 and Day 14, except for claudin-1 on Day 14 and TNF-alpha on Day 3 (P > 0.05). Compared with HT group, birds in HT supplemented with resveratrol group decreased (P < 0.05) crypt depth (in jejunum on Day 3, ileum on Day 14), mRNA levels of expression of HSP70, HSP90, nuclear factor kappa B, mucin-4, claudin-2 and serum concentrations of endotoxin, IL-1 beta, IL-4, IL-6 and TNF-alpha, and increased (P < 0.05) average daily feed intake (+11%), average daily gain (+22%) and villus height, villus height to crypt depth ratio, mRNA levels of expression of mucin-2, sIgA, claudin-1,zona occludens-1 and serum concentrations of interferon gamma, although with few fluctuations between Day 3 and Day 14.Conclusions: Dietary supplementation of resveratrol was effective in partially alleviating the adverse effects of heat stress on growth performance and intestinal barrier function in yellow-feather broilers, by restoring the impaired villus-crypt structure, altering the mRNA expression of intestinal HSPs, mucins, sIgA and tight junction-related gene, and inhibiting secretion of pro-inflammation cytokines.