Heat Stress and Gut Health in Broilers: Role of Tight Junction Proteins

Simple SummaryThe physiological and metabolic responses of broiler chickens to control thermoregulation during heat stress divert energy from efficient production in addition to increasing morbidity and mortality. Therefore, heat stress amelioration strategies may improve the productivity of poultry meat production over the summer months and in tropical regions. Increasingly, low-cost feed additives are being investigated as potential amelioration strategies against heat stress. Scholars have investigated the effects of betaine alone on growth performance and gut physiology, while a small number of studies have been made regarding the impacts of the combination of betaine and antioxidants. Therefore, this study was conducted to investigate the effects of the osmolyte betaine and selenium and vitamin E supplementation on growth performance, physiological responses, and gut physiology in broiler chickens exposed to cyclic heat stress.AbstractHeat stress (HS) is an environmental stressor challenging poultry production and requires a strategy to cope with it. A total of 288-day-old male broiler chicks were fed with one of the following diets: basal diet, basal with betaine (BET), or with selenium and vitamin E (AOX), or with a combination of BET and AOX, under thermoneutral and cyclic HS. Results showed that HS reduced average daily feed intake (ADFI) (p = 0.01) and average daily gain (ADG) (p < 0.001), and impaired feed conversion ratio (FCR) (p = 0.03) during rearing period (0–42 day). BET increased ADG (p = 0.001) and decreased FCR (p = 0.02), whereas AOX had no effects. Breast muscle weight was decreased by HS (p < 0.001) and increased by BET (p < 0.001). Rectal temperature was increased by HS (p < 0.001) and improved by BET overall. Respiration rate was increased by HS (p < 0.001), but BET decreased it during HS (p = 0.04). Jejunum transepithelial resistance was reduced by HS and had no effect on permeability whereas BET increased jejunum permeability (p = 0.013). Overall, the reductions in ADG of broiler chickens during HS were ameliorated by supplementation with BET, with much of the increase in ADG being breast muscle.

Section: Discussionsupporting

confidence: 71%

“…In the present study, dietary BET increased permeability of jejunum compared to other diets. Dietary AOX and BET can reduce gut cell damage and improve (reduce) intestinal permeability in broilers [ 49 , 50 ]. The reason for differences between our results with other studies may be due to the difference in the site of measurement.…”

Section: Discussionmentioning

confidence: 99%

Betaine and Antioxidants Improve Growth Performance, Breast Muscle Development and Ameliorate Thermoregulatory Responses to Cyclic Heat Exposure in Broiler Chickens

Shakeri

Cottrell

Wilkinson³

et al. 2018

“…Intestinal epithelial cells are connected with gap junctions, tight junctions, adherent junctions, and desmosomes [54]. Under the influence of high temperature, the barrier function is compromised, and the intestinal lumen content enters the bloodstream, causing chronic systemic inflammation [25]. The activation of Toll-like receptors (TLR) by microbial signatures triggers myeloid differentiation primary response 88 (MyD88), which in turn induces cytokine secretion [55].…”

Section: Immune-related Gene Expression Signaturesmentioning

confidence: 99%

“…HS in poultry influences the composition of intestinal microbiota [23], leading to gut dysbiosis [24]. Unstable microbiota impairs the morphology and barrier function of the GIT [25]. Feed additives such as prebiotics support the gut microbiota under stressful conditions [26][27][28].…”

Section: Introductionmentioning

confidence: 99%

Splenic Gene Expression Signatures in Slow-Growing Chickens Stimulated in Ovo with Galactooligosaccharides and Challenged with Heat

Pietrzak

Dunisławska

Siwek

et al. 2020

Galactooligosaccharides (GOS) that are delivered in ovo improve intestinal microbiota composition and mitigate the negative effects of heat stress in broiler chickens. Hubbard hybrids are slow-growing chickens with a high resistance to heat. In this paper, we determined the impact of GOS delivered in ovo on slow-growing chickens that are challenged with heat. The experiment was a 2 × 2 × 2 factorial design. On day 12 of incubation, GOS (3.5 mg/egg) was delivered into the egg (n = 300). Controls (C) were mock-injected with physiological saline (n = 300). After hatching, the GOS and C groups were split into thermal groups: thermoneutral (TN) and heat stress (HS). HS (30 °C) lasted for 14 days (days 36–50 post-hatching). The spleen (n = 8) was sampled after acute (8.5 h) and chronic (14 days) HS. The gene expression of immune-related (IL-2, IL-4, IL-6, IL-10, IL-12p40, and IL-17) and stress-related genes (HSP25, HSP90AA1, BAG3, CAT, and SOD) was detected with RT-qPCR. Chronic HS up-regulated the expression of the genes: IL-10, IL-12p40, SOD (p < 0.05), and CAT (p < 0.01). GOS delivered in ovo down-regulated IL-4 (acute p < 0.001; chronic p < 0.01), IL-12p40, CAT and SOD (chronic p < 0.05). The obtained results suggest that slow-growing hybrids are resistant to acute heat and tolerant to chronic heat, which can be supported with in ovo GOS administration.

“…These stress factors affect the health status of poultry and the safety of poultry products, while they adversely influence the intestinal oxidative status and disrupt the normal function of enterocytes, causing an abnormality in nutrient absorption and diseases [ 3 ]. As a consequence of suppressed nutrient absorption, the production indexes (such as feed efficiency and survival rate) are impaired, leading to heavy economic losses to the poultry industry [ 4 ].…”

Section: Introductionmentioning

confidence: 99%

The Laetiporus sulphureus Fermented Product Enhances the Antioxidant Status, Intestinal Tight Junction, and Morphology of Broiler Chickens

Lin

Lee

2021

The Laetiporus sp. is a fungal species that is traditionally used for medicinal purposes. This study investigated the effects of the Laetiporus sulphureus fermented product (FL) as a feed supplementation on the antioxidant activities, the intestinal Tight Junction (TJ) mRNA expression, and the intestinal morphology of broiler chickens. Four-hundred one-day-old male broilers (Ross 308) were randomly allocated to five experimental diets: (1) a corn-soybean meal basal diet (control), (2) a basal diet replaced with 5% Wheat Bran (5% WB), (3) a basal diet replaced with 10% WB (10% WB), (4) a basal diet replaced with 5% FL (5% FL), and (5) a basal diet replaced with 10% FL (10% FL). The FL-supplemented groups exhibited a better feed conversion ratio in the overall experimental period compared to the WB and control groups. The serum antioxidant profiles of 35-day-old broilers showed that, compared to the control and 10% WB groups, the 5% FL supplementation group had a significantly increased superoxide dismutase activity, while it down-regulated the concentration of malondialdehyde in the serum (p < 0.05). The assessment of selected antioxidant gene expression showed that the 5% FL group significantly elevated heme oxygenase-1 and nuclear factor erythroid 2–related factor 2 expression, compared to the control and WB groups (p < 0.05). Furthermore, both of the FL supplemented groups had a significantly higher expression of glutathione peroxidase and catalase, compared to that of the WB and control groups in the jejunum (p < 0.05). The TJ mRNA expression in the jejunum showed that 5% FL significantly elevated the zonula occludens-1, claudin-1, and mucin-2 expression (p < 0.05), while 5% and 10% FL supplementation significantly improved OCLN expression in both the jejunum and ileum, compared to control group (p < 0.05). The intestinal morphology of 35-day-old broilers showed that a 5% FL supplementation significantly increased the villus height in the ileum and jejunum, compared to the WB and control groups (p < 0.05). Moreover, the 5% and 10% FL supplementation groups had a significantly higher villi:crypt ratio in the ileum, compared to the WB and control groups (p < 0.05). To conclude, FL supplementation improved the antioxidative status, the TJ mRNA expression, and the intestinal morphology, and it was accompanied by a lowered feed conversion ratio in broilers. Finally, 5% supplementation had the overall best results in improving the antioxidant status, TJ mRNA expression, and intestinal morphology of broilers.