Polymorphisms of the ACSS2 gene influence milk production traits in Chinese Holstein cows

Background Milk production traits in dairy cattle are of great significance for the dairy industry. Acetyl‐CoA synthase 2 (ACSS2) plays a vital role in lipid metabolism and energy homeostasis, yet its genetic contribution to milk production traits in dairy cattle remains largely unexplored, which prompts us to conduct this study to explore potential genetic markers for improving milk production. Aim(s) This study aimed to identify single nucleotide polymorphisms (SNPs) within the bovine ACSS2 gene and investigate their associations with milk production traits in dairy cattle. Methods These SNPs were genotyped in 992 Chinese Holstein cows using the Sequenom MassARRAY platform. Association analyses were performed by using SHEsis and SPSS Ver.26.0 to examine the relationships between these SNPs and milk production traits. Major Findings Three novel SNPs (g.320 A>G, g.33012 T>C, and g.45063 T>C) within the intronic regions of the bovine ACSS2 gene were identified, while g.33012 T>C and g.45063 T>C were also associated with protein concentration ( P < 0.01). Additionally, g.33012 T>C showed a moderate association with fat concentration ( P < 0.05). A strong linkage disequilibrium was observed between g.320 A>G and g.45063 T>C. No significant effects were found for somatic cell score. Industrial Implications The results suggest that ACSS2 intronic polymorphisms may serve as molecular markers for improving milk yield and composition in dairy cattle through marker‐assisted selection. However, further validation in diverse populations is needed to confirm their functional roles and breeding utility.