A Capsaicin-Based Phytogenic Solution Improves Performance and Thermal Tolerance of Heat-Stressed Growing Pigs.

Simple Summary: Exposure to heat stress significantly impairs the productive performance of growing pigs. Supplementing their diet with phytogenic solutions, especially those containing Capsicum spp., can boost their thermal tolerance due to the activities of its principal active metabolite, capsaicin. This improvement aids in better nutrient consumption and efficient utilization for growth. In this study, we explored the effectiveness of a Capsicum spp.-based dietary phytogenic solution in alleviating the effects of heat stress on pigs. Our findings showed that this supplementation notably enhanced the pigs' performance under heat stress conditions by increasing feed intake and improving feed efficiency. It also positively affected thermoregulatory responses, as evidenced by lowered body temperatures. Moreover, the supplement improved antioxidant defenses and heat shock protein responses and bolstered intestinal integrity and post-absorptive metabolism. Overall, the results indicate that a dietary phytogenic solution derived from Capsicum spp. can effectively counteract some of the detrimental effects of heat stress in pigs, leading to improved overall productive performance. Exposure to heat stress (HS) detrimentally affects pig performance. This study explored whether a dietary phytogenic solution based on Capsicum spp. (PHY) could enhance the thermal tolerance of heat-stressed growing pigs. Forty-two individually housed pigs were randomly assigned to three treatments: thermoneutral pigs on a control diet (TN-C) and pigs subjected to HS fed the control diet either without (HS-C) or with supplemental PHY (HS-PHY). The TN-C group exhibited increased average daily gain (ADG) and feed intake (FI) compared to both HS-C (p < 0.01) and HS-PHY pigs (p < 0.05) and better feed efficiency compared to HS-C pigs only (p < 0.01). However, the HS-PHY pigs showed significantly higher FI (p < 0.01) and ADG (p < 0.05) compared to HS-C pigs. HS pigs displayed higher body temperatures (BTs) than TN pigs (p < 0.01), yet HS-PHY pigs experienced a lesser increase in BT compared to HS-C pigs (p < 0.05). Supplementation with PHY mitigated some effects of HS, increasing serum superoxide dismutase and catalase activity, reducing HSP90 expression in longissimus dorsi muscle, and elevating jejunal villus height compared to HS-C pigs (p < 0.05), reaching levels akin to TN-C pigs. Additionally, PHY supplementation resulted in lower serum urea levels than HS-C pigs (p < 0.01) and similar myosin gene expression to TN-C pigs (p > 0.1), suggesting enhanced amino acid post-absorptive utilization for lean tissue growth. In conclusion, dietary PHY supplementation partially offset the adverse effects of HS on pig performance by improving thermal tolerance. [ABSTRACT FROM AUTHOR]