A Plant‐Derived Functional Oral Formulation Improves Growth Performance and Hepatic Metabolic Function in Poultry Under Heat Stress: A Nutritional Intervention Study

Abstract

Heat stress (HS) disrupts growth performance, redox balance, and hepatic metabolic function in broilers, posing a major challenge to poultry production. Therefore, effective nutritional strategies based on plant‐derived bioactive formulations are needed to improve physiological resilience under heat stress. Yinhuang oral liquid (YOL), a functional herbal formulation, has previously shown hepatoprotective potential in experimental models. This study evaluated its nutritional effects on growth performance, oxidative status, and hepatic function in broilers exposed to HS, together with the possible involvement of autophagy‐related regulation. YOL supplementation reduced feed conversion ratio (FCR), alleviated hepatic histopathological alterations, reduced serum total bile acid (TBA) levels, and restored albumin (ALB) to near‐normal levels. YOL also improved oxidative status by decreasing hepatic malondialdehyde (MDA) levels and enhancing glutathione (GSH) activity. In addition, transmission electron microscopy showed improved mitochondrial morphology and enhanced autophagy in the liver of HS‐exposed broilers receiving YOL. Network pharmacology analysis indicated that the mTOR signaling pathway and its downstream autophagy‐related pathway were closely associated with the effects of YOL under HS conditions. Molecular docking further suggested strong binding affinities of baicalin, wogonoside, oroxylin A‐7‐O‐glucuronide, and scopolin with mTOR. At the molecular level, YOL increased the hepatic mRNA levels of LC3, Beclin1, and mTOR, up‐regulated the protein expression of Beclin1, mTOR, and p‐ULK1, reduced p‐mTOR and ULK1 levels, and significantly increased the protein expression of LC3‐I, LC3‐II, Atg4B, Atg7, Atg5, Atg12, and Atg16L1 compared with the HS group. These findings suggest that YOL as a functional herbal formulation may serve as a promising nutritional intervention to improve growth performance, oxidative status, and hepatic metabolic function in heat‐stressed broilers, partly through modulation of mTOR/ULK1‐related autophagy.