Effects and potential mechanism of dietary vitamin C supplementation on hepatic lipid metabolism in growing laying hens under chronic heat stress.

Chronic heat stress (CHS)-induced fatty liver syndrome (FLS) is one of the major problems faced in poultry industry. However, the heat stress response as well as the alleviating strategies for growing laying hens is rarely concerned until nowadays. In this study, 12-wk-old laying hens were subjected to the CHS condition with or without dietary supplementation of 300 mg/kg vitamin C, we found that CHS can also remarkably impair the growth performance and liver functions and induce the hepatic lipid metabolism disorders in the growing laying hens. Vitamin C supplementation successfully mitigated the hepatic lipid accumulation, while showed no alleviating effect on the liver functions. Metabolomic analysis further identified 173 differential metabolites between CHS and HSV groups, which are mainly enriched in the pathways including the cellular components, vitamin and amino acid metabolism and the energy substance metabolism. The results suggest that vitamin C supplementation can effectively alleviate the hepatic lipid deposition in growing laying hens under CHS probably through altering their energy metabolism patterns.