Liu Zixin, Jiang Aoyu, Lv Xiaokang, Fan Dingkun, Chen Qingqing, Wu Yicheng, Zhou Chuanshe, Tan Zhiliang
Key Laboratory for Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China.
University of the Chinese Academy of Sciences, Beijing 100049, China.
Metabolites. 2024 Apr 16;14(4):227. doi: 10.3390/metabo14040227.
The production performance of dairy cattle is closely related to their metabolic state. This study aims to provide a comprehensive understanding of the production performance and metabolic features of Sanhe dairy cattle across different parities, with a specific focus on evaluating variations in milk traits and metabolites in both milk and serum. Sanhe dairy cattle from parities 1 to 4 (S1, n = 10; S2, n = 9; S3, n = 10; and S4, n = 10) at mid-lactation were maintained under the same feeding and management conditions. The milk traits, hydrolyzed milk amino acid levels, serum biochemical parameters, and serum free amino acid levels of the Sanhe dairy cattle were determined. Multiparous Sanhe dairy cattle (S2, S3, and S4) had a greater milk protein content, lower milk lactose content, and lower solids-not-fat content than primiparous Sanhe dairy cattle (S1). Moreover, S1 had a higher ratio of essential to total amino acids (EAAs/TAAs) in both the serum and milk. The serum biochemical results showed the lower glucose and total protein levels in S1 cattle were associated with milk quality. Furthermore, ultra-high-resolution high-performance liquid chromatography with tandem MS analysis (UPLC-MS/MS) identified 86 and 105 differential metabolites in the serum and milk, respectively, and these were mainly involved in amino acid, carbohydrate, and lipid metabolism. S1 and S2/S3/S4 had significantly different metabolic patterns in the serum and milk, and more vitamin B-related metabolites were significantly higher identified in S1 than in multiparous cattle. Among 36 shared differential metabolites in the serum and milk, 10 and 7 metabolites were significantly and strongly correlated with differential physiological indices, respectively. The differential metabolites identified were enriched in key metabolic pathways, illustrating the metabolic characteristics of the serum and milk from Sanhe dairy cattle of different parities. L-phenylalanine, dehydroepiandrosterone, and linoleic acid in the milk and N-acetylornithine in the serum could be used as potential marker metabolites to distinguish between Sanhe dairy cattle with parities of 1-4. In addition, a metabolic map of the serum and milk from the three aspects of carbohydrates, amino acids, and lipids was created for the further analysis and exploration of their relationships. These results reveal significant variations in milk traits and metabolites across different parities of Sanhe dairy cattle, highlighting the influence of parity on the metabolic profiles and production performance. Tailored nutritional strategies based on parity-specific metabolic profiles are recommended to optimize milk production and quality in Sanhe cattle.
奶牛的生产性能与其代谢状态密切相关。本研究旨在全面了解不同胎次三河奶牛的生产性能和代谢特征，特别关注评估牛奶性状以及牛奶和血清中代谢物的变化。选取处于泌乳中期的第1至4胎次的三河奶牛（S1，n = 10；S2，n = 9；S3，n = 10；S4，n = 10），在相同的饲养和管理条件下进行饲养。测定了三河奶牛的牛奶性状、水解牛奶氨基酸水平、血清生化参数和血清游离氨基酸水平。经产三河奶牛（S2、S3和S4）的乳蛋白含量较高，乳糖含量较低，非脂固形物含量低于初产三河奶牛（S1）。此外，S1血清和牛奶中的必需氨基酸与总氨基酸之比（EAA/TAA）较高。血清生化结果表明，S1奶牛较低的葡萄糖和总蛋白水平与牛奶品质有关。此外，超高效液相色谱串联质谱分析（UPLC-MS/MS）分别在血清和牛奶中鉴定出86种和105种差异代谢物，这些代谢物主要参与氨基酸、碳水化合物和脂质代谢。S1与S2/S3/S4在血清和牛奶中的代谢模式存在显著差异，且S1中更多与维生素B相关的代谢物显著高于经产奶牛。在血清和牛奶中共有的36种差异代谢物中，分别有10种和7种代谢物与差异生理指标显著且高度相关。鉴定出的差异代谢物在关键代谢途径中富集，阐明了不同胎次三河奶牛血清和牛奶的代谢特征。牛奶中的L-苯丙氨酸、脱氢表雄酮和亚油酸以及血清中的N-乙酰鸟氨酸可作为区分1至4胎次三河奶牛的潜在标记代谢物。此外，从碳水化合物、氨基酸和脂质三个方面构建了血清和牛奶的代谢图谱，以便进一步分析和探索它们之间的关系。这些结果揭示了三河奶牛不同胎次间牛奶性状和代谢物存在显著差异，突出了胎次对代谢谱和生产性能的影响。建议根据特定胎次的代谢谱制定针对性的营养策略，以优化三河奶牛的产奶量和品质。
