Age associated differences in the composition and function of yak milk

This is the authors' abstract. We don't add key points for this paper.

Maternal age is a key physiological determinant of mammary gland function, yet its influence on milk molecular architecture remains poorly defined. Here, we applied an integrative multi-omics framework combining whey proteomics, milk fat globule membrane (MFGM) proteomics, metabolomics, and lipidomics to characterize age-associated molecular alterations in yak milk. Compared with milk from junior yaks (JY, 3–4 years), senior yaks (SY, 8–9 years) exhibited a coordinated phenotype featuring higher levels of several nutritional components, alterations in inflammation-related molecules, and lipid remodeling. Proteomic analyses revealed consistent alterations in whey and MFGM proteins involved in immune regulation and membrane lipid metabolism. Metabolomic profiling identified nine candidate age-associated metabolites linked to energy metabolism and redox homeostasis. Lipidomic analysis showed increased lipid species, with six candidate lipids with biomarker potential derived from glycerolipids, sphingolipids, and phospholipids. Collectively, these findings reveal coordinated age-associated alterations in the proteomic, metabolic, and lipid profiles of yak milk and provide a multi-omics basis for evaluating milk quality.