Early Compound Nutritional Intervention Improves Hair Follicle Development in Northwest Xizang White Cashmere Goats: An Analysis Based on Skin Multi-Omics.

The Northwest Xizang White Cashmere goat has a high global reputation for good goat cashmere germplasm characteristics, and its cashmere industry is the economic pillar of the herdsmen in the northwest plateau of Xizang. Cashmere is produced by the secondary hair follicles of the skin, and the key period of hair follicle development is from birth to 3 months old. This study aimed to explore how early compound nutritional intervention affects lamb growth performance and secondary hair follicle development. We assessed skin follicle density and performed skin transcriptomic and multi-omics analyses to clarify this regulatory effect. The trial was performed at the Northwest Xizang White Cashmere Goat Breeding Farm, Ritu County, Ngari region, Xizang. Thirty newborn single lambs of comparable birth status were randomly divided into control and early compound nutritional intervention groups (n = 15 per group). The results showed that early compound nutritional intervention significantly increased the secondary hair follicle density, total hair follicle density, and secondary/primary hair follicle (S/P) value of lambs (p < 0.05). However, there was no significant difference in the average cashmere fineness between the two groups (p > 0.05). The transcriptome, proteome, and metabolomics analyses of the skin revealed candidate genes related to hair follicle development and the regulation of cashmere fineness: keratin structural genes (KRT10, KRT18, KRT26), cell proliferation and adhesion-related regulatory genes (ITGB2, CSF1R, AKT1), and extracellular matrix coding genes (COL6A1, COL6A2, COL6A6). Moreover, the results revealed that key proteins related to hair follicle development include RBP4, KAP13-3, KRTAP3-1, KRTAP27-1, DKK3, ITGB2, and DUSP23. The differentially expressed metabolites, 15-Deoxy-delta12,14-Prostaglandin J2 and Thromboxane B2 (TXB2), modulate prostaglandin-associated pathways; altered pathway activity subsequently regulates the expression of hair follicle functional genes and key proteins, which may in turn indirectly regulate hair follicle growth and development, thereby affecting hair follicle density and, by extension, cashmere production performance. Therefore, early compound nutritional intervention of Northwest Xizang White Cashmere goats promotes the growth and development of secondary hair follicles. The identified candidate genes and key proteins involved in secondary hair follicle development provide a reference for exploring the mechanism of hair follicle development.