The study investigated resveratrol’s effect on growth performance, intestinal development, and antioxidant capacity of broilers subjected to heat stress (HS). A total of 162 21-day-old male AA broilers were randomly divided into 3 treatment groups with 6 replicates of 9 birds each. The 3 treatment groups were as follows: the control (CON), in which broilers were housed at 22 ± 1 °C for 24 h day⁻¹, and the HS and HS + resveratrol (400 mg/kg) groups, in which broilers were housed at 33 ± 1 °C for 10 h a day from 8:00 to 18:00 and 22 ± 1 °C for rest of the time. Results indicated that birds in the HS group exhibited lower (p < 0.05) final body weight (BW) and average daily gain (ADG) compared with birds in the CON group. HS birds also had lower (p < 0.05) relative jejunum weight, relative ileum and jejunum length, jejunal villus height, and villus height to crypt depth ratios than the CON group. The activities of glutathione peroxidase (GPX), glutathione S-transferase (GST), superoxide dismutase (SOD), and the mRNA levels of NF-E2-related factor 2 (Nrf2), SOD1, and GPX were also lower (p < 0.05) in the HS than CON group. The HS group had higher (p < 0.05) protein carbonyl (PC) contents and Kelch-like ECH-associated protein 1 (Keap1) mRNA levels. Compared with HS group, the HS + resveratrol group exhibited higher (p < 0.05) BW and ADG, relative jejunum weight, relative length of ileum, jejunal villus height, activities of GPX and GST, and mRNA levels of Nrf2 and SOD1, but they had lower (p < 0.05) PC content and Keap1 mRNA levels. In conclusion, resveratrol can improve the intestinal development and antioxidant function of broilers under HS, and therefore improve growth performance. The mechanism by which resveratrol enhances the intestinal antioxidant capacity is mediated by Nrf2 signaling pathway.

Studies have indicated that dietary resveratrol (RES) improves the meat quality of broilers subjected to heat stress (HS), but the mechanism of action remains unclear. Therefore, the main purpose of this study was to investigate the effect of RES on meat quality, muscle antioxidant status, and its mechanism of action in broilers under HS. A total of 162 male AA broilers at 21 days old with similar weight were randomly assigned to 3 treatment groups with 6 replicates each. The control group (ambient temperature: 22 ± 1 °C) and HS group (ambient temperature: 33 ± 1 °C for 10 h a day from 8:00 to 18:00 and 22 ± 1 °C for the remaining time) were fed a basal diet and the HS + RES group was fed a basal diet with 400 mg/kg RES. The feeding was conducted for 21 continuous days. The results indicated that HS decreased final body weight (BW), average daily gain (ADG), average daily feed intake (ADFI), breast and leg muscle yield, a*_24h, pH_24h, the activities of catalase (CAT), glutathione S-transferase (GST) and glutathione peroxidase (GSH-Px), and mRNA levels of nuclear factor erythroid 2–related factor 2 (Nrf2), heme oxygenase-1 (HO-1), NADPH quinone oxidoreductase 1 (NQO1), and GSH-Px (p < 0.05). HS also increased b*_45min, L*_24h, drip loss, malondialdehyde (MDA) content, and kelch-like epichlorohydrin-associated protein 1 (Keap1) mRNA level (p < 0.05). Compared with the HS group, the HS + RES group exhibited a higher ADG, breast and leg muscle yield, a*_24h, pH_24h, activities of GST and GSH-Px, and mRNA levels of Nrf2, HO-1, and NQO1 but had lower drip loss and Keap1 mRNA level (p < 0.05). RES can improve meat quality and the muscle antioxidant ability of heat-stressed broilers by activating the Nrf2 signaling pathway.

This study investigates the effects of an encapsulated organic acid and essential oil mixture (OAEO) on the growth performance, immuno-antioxidant capacity and intestinal health of weaned piglets. In total, 120 weaned piglets (23 days of age; 6.96 ± 0.08 kg) were randomly allotted to four treatments (six replicates/group; five piglets/replicate): the control group (CON) was fed the basal diet (BD), the antibiotic growth promoters group (AGP) received the BD with 20 mg/kg colistin sulphate and 10 mg/kg bacitracin zinc, and OAEO1 and OAEO2 were fed the BD with 1000 mg/kg and 2000 mg/kg OAEO, respectively. The trial lasted 21 days and then one piglet per replicate was selected for sample collection. OAEO increased the average daily gain, spleen index, serum interleukin (IL)-10, immunoglobulin (Ig) G and IgA levels; serum superoxide dismutase and glutathione peroxidase (GPX) activities; and jejunal villus height (VH), VH/crypt depth, goblet cell number, and amylase and trypsin activities (p < 0.05) compared with CON but reduced the diarrhea rate, serum tumor necrosis factor (TNF)-α, malondialdehyde (MDA), and _D-lactic acid contents and diamine oxidase (DAO) activity (p < 0.05). OAEO also increased the jejunal zonula occludens-1, occludin, claudin-1, mucin-2, nuclear factor erythroid 2-related factor 2 (Nrf2), GPX and IL-10 mRNA levels, GPX activity and IL-10 content (p < 0.05) compared with CON but reduced jejunal MDA, IL-1β and TNF-α contents and Toll-like receptor (TLR) 4, nuclear factor (NF)-κB and TNF-α mRNA levels (p < 0.05). In addition, AGP increased ADG, serum IgA level and GPX activity, jejunal trypsin activity and IL-10 content and mRNA level (p < 0.05) compared with CON but reduced the serum TNF-α content and DAO activity and jejunal NF-κB mRNA level (p < 0.05). Overall, OAEO as an alternative to AGP improved the growth performance, immuno-antioxidant status and gut health of weaned piglets partly via activating the Nrf2 signaling pathway and suppressing the TLR4/NF-κB signaling pathway.