Recently,the Poultry Nutrition and Feed Innovation Team from the Institute of Feed Research, Chinese Academy of Agricultural Sciences revealed the ameliorative effects of methionine sources, ratio of total sulfur amino acids to lysine (TSAA:Lys), and vitamin E on improving production performances, antioxidant potential, and hepatic oxidation in aged laying hens. The results were published in Poultry Science .

Aged laying hens, with their declining antioxidant capacity are vulnerable to reactive oxygen species (ROS) and free radicals, which can lead to various liver metabolic disorders. Both methionine and VE are known to be efficient in the antioxidant defense system. However, the current industry standards for TSAA:Lys and VE levels may be insufficient to meet the dietary requirement of aged laying hens in aging conditions. Thus, this study aimed to explore the effect of methionine sources, TSAA: Lys, and VE levels on production performance, lipid metabolism, and liver-related gene expression in aged laying hens.

The results showed that adding of a lower level of VE increased albumen height and haugh unit. In addition, supplementation of methionine with 0.95 TSAA: Lys ratio reduced serum Triglycerides, total cholesterol, low-density lipoprotein, and very low-density lipoprotein (VLDL) and superoxide dismutase (SOD) and catalase activities (CAT) in the liver. Moreover, OH-Met at 0.90 and DL-Met at 0.95 of the TSAA: Lys ratio had a significant reduction of malondialdehyde (MDA). Taken together, our study showed that production performance was not influenced by Met sources, while OH-Met had beneficial effects on maintaining normal liver function in aged laying hens through improvement in the glutathione synthetase pathway and carnitine palmitoyltransferase-1 alpha (CPT-1α). In addition, the TSAA: Lys ratio at 0.95 combined with 20 IU of VE appears to be optimal for sustaining laying performance and improved liver health in aged laying hens by modifying lipid metabolism. This includes the regulation of fatty acid synthase and the enhancement of hepatic antioxidative functions, such as activation of nuclear factor erythroid 2-related factor 2 (Nrf2), catalase activity, and glutathione disulfide (GSSG). This study provides new ideas for improving the liver health of laying hens in the late stage of egg production.

This study wassupported by the National Key R&D Program of China, the Beijing Innovation Consortium of Agriculture Research System, and the Agricultural Science and Technology Innovation Program (ASTIP).

Original link: https://doi.org/10.1016/j.psj.2024.104415

Source: Guangtian Ma, (t871173890@163.com)