The STAT gene in dairy animals, especially cows, plays a crucial role in milk production and reproductive traits. Different STAT genes are involved in regulating milk composition, embryo survival, and conception rates. Studies have shown that STAT1 and STAT3 are consistently expressed during different stages of pregnancy and lactation, while STAT4 and STAT5 are developmentally regulated. Among these, STAT5A is particularly important for reproduction and milk production. By studying the genetic variations in the STAT gene, researchers can better understand how it affects milk yield, fat content, and fertility in dairy animals. This information can be used for selective breeding to improve dairy animal traits.