Day-old chicks (n=125) in 5 groups were raised under standard management till 21 st day. From 22 nd-35 th day, control (TN) group received 26°C whereas four groups were exposed to cyclic cold stress (CS) (15°C±2°C for 8 hours/day). The COLD (control cold-stressed) and TN groups received corn-based diet (CBD) whereas CS+0.1%β-GOS, CS+0.2%β-GOS and CS+0.5%β-GOS groups, received CBD supplemented with β-GOS (0.1%, 0.2% and 0.5%, respectively). Results demonstrated that cold-exposed birds were

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... ted with poor feed efficiency (FE), reduced body weights (BW), relative weights (RW) of ceca, intestinal villus surface area (VSA) and duodenal intraepithelial lymphocyte count (IELs) compared with TN group. COLD group also had higher serum cortisol and triiodothyronine, RW of heart and liver and acidic goblet cells (AGCs) in small intestine when compared with TN group. Dietary supplementation of β-GOS (0.5%) improved FE, RW of ceca and duodenal AGCs whereas reduced serum cortisol and jejunal IELs when compared with COLD group. Moreover all dietary inclusions of β-GOS (0.1%, 0.2% and 0.5%) also enhanced intestinal VSA and jejunal AGCs when compared with COLD group. In conclusion, dietary β-GOS helped to improve growth performance and serum cortisol along with modulating the intestinal microarchitecture and acidic mucin production in broilers during CS.