Selenium Reprograms the Proteome of Milk Fat Globule Membrane in Yak Colostrum

In mammals, selenium (Se) enhances antioxidant and immune functions, but its effect on milk fat globule membrane (MFGM) proteins in yak colostrum remains unclear. Astral-DIA proteomics technology was employed herein for profiling MFGM proteins in yak colostrum obtained from the control (C), low-dose Se-supplemented (L), and high-dose Se-supplemented (H) groups treated with 0, 0.3, and 0.6 mg of Se/kg of dry matter, respectively. A total of 4079, 4083, and 4323 MFGM proteins were identified in the groups C, L, and H, respectively. Pairwise comparisons of the groups C versus L, C vs H, and L vs H revealed 652, 814, and 570 differentially expressed MFGM proteins, respectively. Low-dose Se supplementation primarily enhanced the RNA processing and translation-associated pathways. High-dose Se, however, triggered proteome remodeling by modulating histone modifications and ubiquitin-dependent protein turnover. Se supplementation at different doses reshaped the MFGM composition in yak colostrum, potentially optimizing neonatal immunity and metabolism.