Xing Ronghui, Fan Kefeng, Fan Zongze, Wang Longfei, Huang Yanqun, Zhang Huaiyong, Chen Wen, Si Xuemeng
Institute of animal science and technology, Henan Agricultural University, Zhengzhou, 450046, Henan, China.
College of Animal Science and Technology, Henan University of Animal Husbandry and Economy, Zhengzhou, 450046, Henan, China; Jiu Yi traditional Chinese Medicine Research Institute, Zhengzhou, 450046, Henan, China.
Poult Sci. 2025 Feb;104(2):104777. doi: 10.1016/j.psj.2025.104777. Epub 2025 Jan 3.
As the extension of the egg-laying cycle, heightened energy and lipid metabolism cause excessive lipid accumulation, resulting in rapid decline in laying performance during the late laying period. Bile acids (BAs), synthesized from cholesterol in the liver, are potent metabolic and immune signaling molecules involved in lipid metabolism and the regulation of energy homeostasis. However, under different dietary protein levels, the role of BAs on hepatic lipid metabolism of laying hens at the late phase remains unclear. This experiment aimed to evaluate the effects of porcine BAs supplementation on performance, lipid metabolism, antioxidant status and amino acid metabolism in late-phase laying hens fed diets with different protein level. A total of 192 Hy-Line Brown laying hens (62 weeks of age) were randomly assigned to one of four treatment groups, in a 2 × 2 factorial design, with 8 replicates per treatment. The hens were fed diets with either normal protein (16.42 %) or low-protein (15.35 %) levels, with or without BAs supplementation (120 mg/kg for the first 56 days, followed by 200 mg/kg for the next 42 days). The results demonstrated that dietary BAs supplementation significantly enhanced egg production and feed intake (P < 0.05) although it has no notable effect on egg quality. Bile acids supplementation effectively reduced liver total cholesterol (TC), triglyceride (TG), as well as malondialdehyde (MDA) levels, while also ameliorating lipid deposition through the regulation of expression of lipid metabolism-related genes in late laying hens (P < 0.05). Additionally, the low-protein diets downregulated amino acid catabolism, thereby reducing serum uric acid content and enhancing protein utilization. Further analysis revealed that BAs also positively influenced trypsin activity and increased the expression of amino acid transporters, thereby improving amino acid availability (P < 0.05). In conclusion, this study demonstrated that dietary BAs supplementation could enhance the laying performance in late laying hens, primarily by improving hepatic lipid metabolism, antioxidant capacity, and amino acid availability.
作为产蛋周期的延长，能量和脂质代谢增强导致脂质过度积累，致使产蛋后期产蛋性能迅速下降。胆汁酸（BAs）由肝脏中的胆固醇合成，是参与脂质代谢和能量稳态调节的强效代谢和免疫信号分子。然而，在不同日粮蛋白质水平下，胆汁酸对产蛋后期蛋鸡肝脏脂质代谢的作用仍不清楚。本试验旨在评估添加猪胆汁酸对不同蛋白质水平日粮喂养的产蛋后期蛋鸡生产性能、脂质代谢、抗氧化状态和氨基酸代谢的影响。总共192只海兰褐蛋鸡（62周龄）被随机分配到四个处理组之一，采用2×2析因设计，每个处理8个重复。给母鸡饲喂正常蛋白质水平（16.42%）或低蛋白质水平（15.35%）的日粮，添加或不添加胆汁酸（前56天为120mg/kg，接下来42天为200mg/kg）。结果表明，日粮添加胆汁酸显著提高了产蛋量和采食量（P<0.05），尽管对蛋品质没有显著影响。添加胆汁酸有效降低了肝脏总胆固醇（TC）、甘油三酯（TG）以及丙二醛（MDA）水平，同时还通过调节产蛋后期蛋鸡脂质代谢相关基因的表达改善了脂质沉积（P<0.05）。此外，低蛋白质日粮下调了氨基酸分解代谢，从而降低了血清尿酸含量并提高了蛋白质利用率。进一步分析表明，胆汁酸还对胰蛋白酶活性产生积极影响并增加了氨基酸转运蛋白的表达，从而提高了氨基酸利用率（P<0.05）。总之，本研究表明，日粮添加胆汁酸可以提高产蛋后期蛋鸡的产蛋性能，主要是通过改善肝脏脂质代谢、抗氧化能力和氨基酸利用率来实现。
