| [145] | Hubbard chickens | 35°C, 75% RH, 8 h/day from 21 to 42 days | MOS (0.5% in diet) and/or probiotics (0.1% in diet) | ● MOS increased crypt depth in HS birds.● Villus height and surface area increased in ileum due to MOS and probiotic supplementation under HS.● Villus width and crypt depth increased in HS-probiotic group.● MOS, probiotic and MOS+probiotic enhanced activity of goblet cells under HS. |
| [84] | Broiler chickens at 36 days of age | 36°C for 0 to 10 h for one day | Enhancer (L-glutamine injected intraperitoneally, 0.75 mg/kg BW) vs. inhibitor (quercetin injected intraperitoneally, 5 mg/kg of BW), 1 day before HS | ● Increased GPx and SOD activity, T-AOC and HSP70 in jejunal mucosa by enhancer than by inhibitor.● LDH in jejunal mucosa was lower in enhancer group than inhibitor group.● LDH activity rapidly increased in jejunum during the first 2 h of HS.● Increased serum corticosterone in inhibitor group compared with enhancer group. |
| [85] | Male broiler chickens | 36°C for 0 to 10 h for one day | Intraperitoneally injected with L-glutamine (enhancer, 0.75 mg/kg of BW) or quercetin (inhibitor, 5 mg/kg of BW) for one day before HS | ● No effect on villus height, crypt depth (except decrease in 5 h), or VCR (except increase in 10 h) HSP70 mRNA expression in enhancer group was higher than inhibitor group in jejunum.● Trypsin, amylase, and lipase activities in enhancer group were higher than in inhibitor group. |
| [141] | Ross-708 of mixed sex chickens | 35°C from 1 to 42 days | 0.5% MOS or 0.1% PM | ● MOS and PM increased BW gain and ADFI, and lowered FCR compared with HS-control group.● Probiotic increased villus width and surface area compared with HS-control treatment.● MOS and PM partially alleviated changes of intestinal microstructures damaged by HS. |
| [146] | Wenchang male chickens | 40°C, 52.4% RH for 3 h | 0.2 mL gamma-amino butyric acid solution (50 mg/kg of BW) daily for 35 days | ● Increased GPx, SOD, catalase, T-AOC content in intestinal mucosa.● Decreased MDA content in jejunal and ileal mucosa. |
| [147] | 21-day-old Ross male broilers | 33°C from 08:00 to 06:00 from 21 to 42 days | COS at 1.5 g/kg diet | ● No effect on BW gain, feed intake, and FCR.● Increased number of Lactobacillus, decreased E. coli, and had no effect on Bifidobacterium and Clostridium counts.● Increased villus height and VCR, no effect on crypt depth.● Reduced jejunal FITC-d permeability. |
| [142] | Crossbred gilts (43 kg BW) | 36°C, 50% RH for either 1 or 7 days | 100 (Zn220) and 200 (Zn320) mg/kg diet of Zn as Zn-amino acid complexes | ● BW and feed intake were not affected.● Improved Ileal and colonic TER in Zn220-fed pigs● Ileal and colonic FITC-d permeability increased, and colonic FITC-LPS permeability tended to increase due to HS from days 1 to 7; but Zn supplementation has no effect.● Overall, no effects on ileal glucose, lysine, methionine, and glutamine transport.● Glucose transport linearly decreased with increasing levels of Zn-amino acid on day 1.● No differences on villi height or crypt depth. |
| [143] | Crossbred gilts (39 kg BW) | 32°C, 26% RH for 24 h | WP (80% 98% and 100%) | ● BW, BW gain, and feed intake were not affected by whey protein.● Plasma L-lactate and D-lactate levels increased and tended to increase with HS.● After 24 h of HS, 100% WP-fed pigs had lower plasma D-lactate relative to control-fed pigs.● Decreased Ileal TER (37%) in 80% WP-fed pigs.● Ileal TER decreased in HS whey protein groups. |
| [148] | Hubbard male broiler chicks | 35°C and 64% RH from 09:00 to 14:00 and 21°C from 14:00 to 09:00 | Bacillus subtilis (1 g/kg diet; 2.3 × 108 CFU/g of B. subtilis spores) | ● Increased BW, ADG and feed efficiency, but no effect on feed intake by B. subtilis.● B. subtilis increased villus height, villus surface area, and absorptive epithelial cell area in duodenum and ileum.● B. subtilis increased Lactobacillus and Bifidobacterium and decreased coliforms and Clostridium counts in intestine. |
| [131] | Male Wenchang chickens | 40.5°C, 52.4% RH for 2 h for 15 days | GABA (50 mg/kg of BW) | ● HS decreased activity of sucrase, maltase, alkaline phosphatase, contents of secretory IgA, glutathione, d-xylose, number of lymphocytes, and Na+-K+-ATPase activity of intestinal mucosa.● GABA ameliorated the above effects. |
| [7] | 21-day-old Ross male broiler chickens | 33°C for 10 h/day, from 22 to 42 days | PM (B. licheniformis, B. subtilis, and Lactobacillus plantarum) at 1.5 g/kg diet | ● Probiotic decreased FCR, but no effect on ADG and ADFI.● Probiotics had no effect on TER value and FITC-d permeability in jejunum compared with control diet.● Probiotics increased protein level of OCLN.● Probiotics increased villus height than the control diet. |
| [97] | Male Wenchang chickens | 40.5°C, 52.4% RH for 2 h for 15 days | GABA (0.5%) fed with 0.2 mL | ● GABA increased BW, but no effect on ADG, FCR and fed intake on day 15.● GABA enhanced villus height, crypt depth, mucosa thickness, intestinal wall thickness, and number of goblet cells in duodenum and ileum. |
| [135] | Male Cobb 500 broilers birds | 32°C–27°C vs. 37°C–33°C, decreased 2°C/week until reaching 33°C in third week; for 5 h/day from 29 to 42 day of age | 10 g/kg diet of glutamic acid | ● Glutamic acid increased villus height, crypt depth, and VCR.● Glutamic acid increased BW. |
| [149] | Cobb 500 male broiler chickens | 34°C, 65%–70% RH for 5 h/day from 29 to 42 days | GSE 150, 300, 450 mg/kg of diet and vitamin C at 300 mg/kg of diet | ● GSE or vitamin C did not affect lengths of duodenum, jejunum, ileum, large intestine and cecum.● GSE increased villus height, tended to increase crypt depth, but no effect on VCR and muscle layer thickness jejunum.● No effect of vitamin C on jejunum villus width, crypt depth, VCR, and muscle layer thickness.● GSE, but not vitamin C, lowered ileal coliforms and E. coli populations. |
| [99] | Crossbred gilts (64 kg BW) | 37°C and 40% RH for 12 h | ZnAA | ● No differences of BW loss and feed intake between HS-control and HS-ZnAA pigs.● ZnAA decreased BW and feed intake under HS.● ZnAA had no effect on FITC-d permeability, but increased ileal TER level under HS.● Ileal IL1-β decreased and plasma LBP increased in HS-ZnAA.● Colon MUC2 mRNA abundance elevated in HS-ZnAA AA pigs● Intestinal alkaline phosphatase gene abundance increased in HS-ZnAA.● No effect on ileal and colonic HIF1A protein expression.● No effect on ileal HSP70 protein expression but lowered HSP70 protein expression in colon of HS-ZnAA pigs. |
| [1] | 15-day-old Ross broiler chickens | 38°C–39°C for 8 h for 5 days | GOS at 10 or 25 g/kg diet (6 days prior to HS) | ● GOS prevented HS-induced upregulation of HSF3, HSP70, and HSP90 mRNA in jejunum.● Heat-induced effects on CDH1 mRNA expression and pan-cadherin protein expression in jejunum prevented by GOS.● HS-induced increase in mRNA expressions of CLDN5 and ZO1 dose-dependently alleviated in jejunum by GOS.● GOS (25 g/kg) prevented heat-induced gene TLR-4 induction in jejunum.● Up-regulation of IL6 and IL8 mRNA expressions in jejunum and ileum by HS was prevented by GOS. |
| [71] | 28 day old female Xuefeng black-boned chickens | 37°C for 8 h/day for 15 days | 200, 400, or 600 mg/kg diet of resveratrol for 15 days | ● Resveratrol improved villus morphology, increased goblet cell and lymphocyte numbers at 400 mg/kg.● Resveratrol reduced HSP70, HSP90, and NF-κB protein levels in jejunal villi after 15 days of HS and increased EGF level. |
| [130] | 21 day old Hubbard male broiler chickens | 32°C; 64% RH | 0.5 g butyric acid/kg of feed | ● Butyric acid increased BW and ADG in HS birds.● Butyric acid increased recovery of villus height, villus surface area, relative intestinal weight, and absorptive epithelial cell area in duodenum of HS-birds.● Butyric acid increased intestinal Lactobacillus and Bifidobacterium populations in HS-birds. |
| [94] | Female growing pigs | 35°C 8 h/day, 35% RH for 2 days | 0.2–1.0 mg/kg of Se and 17–200 IU/ kg of vitamin E for 14 days | ● Linearly increased TER value.● Decreased FITC-d permeability quadratically.● Increased GPx2 mRNA abundance.● Se and vitamin E did not affect HSP70, HIF1A, IL8, or TNFA mRNA levels. |
| [30] | Hy-Line Brown laying hens (aged 40 weeks) | 33°C and 60%–70% RH, for 20 days | PM (Enterococcus faecium and B. subtilis) | ● Probiotic increased egg production rate, feed intake, and egg weight under HS.● Probiotic improved eggshell strength, eggshell thickness, and albumen height.● Probiotics increased VCR in ileum (10 days and 20 days) and cecum (20 days) in HS-hens.● Probiotic upregulated expression levels of OCLN, ZO1, and JAM-A in ileum and cecum.● Probiotics reduced mRNA level of HSP70. |
| [93] | Cobb male chickens | 36°C from 08:00 to 18:00 and 26°C from 18:00 to 08:00 from 8 to 35 days | NAC (1 g/kg in diet) | ● NAC increased ADFI, ADG, and reduced FCR.● NAC increased VCR.● NAC increased ATP level in jejunal mucosa.● NAC inhibited the increase of jejunal AMP under HS.● NAC decreased MDA concentration and mRNA levels of HSP70, AMP-activated protein kinase, and heme-oxigenase in intestine.● NAC elevated catalase and trypsine activity in jejunum under HS. |
| [66] | Lohmann layer cockerels | TN (21°C, 62% RH) vs. HS (35°C, 64% RH from 09:00 to 13:00 and 21°C from 13:00 to 09:00) for 30 days | Butyrate at 0.35 g/kg of diet | ● Butyrate increased villus height, surface area, and absorptive epithelial cell area in all intestinal parts under HS.● No effect of butyrate on crypt depth in duodenum and jejunum under HS, but it was greater in ileum.● Butyrate alleviated villi damages and epithelial cell damage in all intestinal sections.● Butyrate increased intestinal and cecal Lactobacillus and Bifidobacterium numbers and decreased Clostridium and coliforms numbers. |
| [86] | 21-day-old Cobb male broiler chickens | 33°C, 70% RH for 10 h for 21 days | 400 mg/kg diet of resveratrol | ● Resveratrol increased final BW but no effect on ADG and ADFI.● Resveratrol increased villus height, VCR and goblet cell numbers, and lowered crypt depth.● Resveratrol increased numbers of Lactobacillus and Bifidobacterium and lowered the numbers of Escherichia coli colonization.● Resveratrol increased intestinal mucosal CLDN1, OCLN, CDH1, and MUC2 mRNA levels.● Resveratrol decreased serum D-lactic acid and FITC-d concentrations in HS birds. |
| [62] | Crossbred gilts (50 kg BW) | 27°C–30°C, 35% humidity for 7 days | Zn at 120 mg/kg diet (60 mg as Zn-sulfate + 60 mg as Zn-amino acid) | ● No effect on ADFI, ADG, and final BW, but FCR tended to decrease.● No effect on TNFA and LPS-binding protein in serum. |
| [144] | 21-day-old Arbor Acres broiler chickens | 36°C for 10 h/day for 20 days | 5 and 10 g/kg diet of glutamine | ● Glutamine increased villus height in HS birds.● Glutamine decreased D-lactate and diamine oxidase activity in HS birds.● Glutamine mediated secretion of cytokines (TNFA and IL10), increased ZO1, CLDN1, and OCLN mRNA levels in HS birds. |
| [76] | Male Arbor Acres plus broiler chickens | Control (20°C) vs. HS (32°C–33°C 8 h/day) for 4–42 days | MOS at 250 mg/kg diet | ● MOS increased ADG, ADFI, and FCR.● MOS decreased mucosal MDA content in jejunum at 42 days under HS.● MOS increased jejunal and ileal villus height and VCR.● MOS increased mRNA abundances of OCLN, and ileal MUC2 and ZO1 in jejunum and ileum, and ileal CLDN3 genes expressions. |
| [138] | 28-day old male Ross-308 broiler chickens | 33°C and 40%–55% humidity for 8 h/day for 10 days | 1 g/kg of betaine in finisher diet | ● Betaine increased ileal villus height and TER.● Betaine decreased Evans blue dye concentration in jejunum and ileum. |
| [134] | Male Arbor Acres broilers from 28 to 42 days | TN (23°C) or subjected to cyclic HS (28°C–35°C–28°C for 12 h daily) | Probiotic (Lactobacillus acidophilus, Lactobacillus plantarum, and Enterococcus faecalis) at a dose of 1.5 × 108 CFU/kg | ● Probiotics had no effect on growth performance except for increased ADFI on days 22–42.● Probiotic increased villus height and VCR in duodenum and jejunum of HS birds on day 42.● Probiotic decreased serum D-lactic acid concentration on day 28.● Probiotic reduced serum TNFA and IL6, but increased IL10 and TGFB1 in HS birds. |
| [139] | Male Cobb50 broiler chickens | TN (26°C) vs. HS (34°C for 8 h daily for 21 days) | 112.5 mg ginseng extract /kg feed | ● Ginseng increased feed intake, BW and FCR.● Ginseng decreased HSPA1A, HSPD and HSPB1 gene expression.● Ginseng upregulated CLDN3, OCLN and CLDN1 (Caco 2). |