Differential expression of lactation associated genes in cattle: a transcriptomic approach to precision dairy breeding

Milk production is a multifactorial trait influenced by species, breed, udder morphology, parity, lactation stage, and the secretory characteristics of mammary epithelial and somatic cells. Molecular approaches, such as mRNA expression profiling, offer valuable insights into the genetic regulation of lactation. Milk somatic cells, abundant in high-yielding crossbred cows like Karan Fries, provide a non-invasive and reliable source for such analyses. In this study, gene expression was assessed in milk somatic cells from six high- and six low-producing Karan Fries cows during peak lactation using quantitative PCR targeting ANXA1, Moesin, S100A8, PDIA3, MFGE8, and RAGE, with GAPDH as the reference gene. Significant differences in gene expression were observed between the two groups. High-producing cows showed marked upregulation of MFGE8 and PDIA3, suggesting their potential roles in enhancing milk synthesis and lipid metabolism. In contrast, low-producing cows exhibited elevated expression of S100A8, which may modulate intracellular calcium dynamics and influence milk secretion. Furthermore, increased expression of RAGE in low yielders indicates a possible inhibitory effect on milk production, potentially associated with inflammatory or cellular stress responses. MFGE8 and PDIA3 emerged as key candidate genes for improving milk yield in Karan Fries cattle, underscoring the role of differential gene expression analysis in advancing precision breeding for enhanced lactation performance in dairy cattle.