What is the primary function of prolactin produced in the cow's endometrium?

Prolactin plays a significant role in the reproductive physiology of cows, particularly regarding its function in supporting pregnancy. In the cow's endometrium, prolactin is involved in several processes critical for maintaining pregnancy. It helps in the development of the placenta and supports the growth of the uterine lining, which is essential for the nourishment of the developing fetus. Additionally, prolactin has immunomodulatory effects, ensuring the maternal immune system does not reject the developing embryo, further facilitating a successful gestation.

While prolactin is often associated with stimulating milk production, particularly in lactation, its primary role produced in the endometrium relates to maintaining the pregnancy rather than actual milk secretion. Other hormones within the reproductive system are more directly involved in stimulating ovulation or regulating metabolism. Therefore, the focus of prolactin's actions in this context highlights its essential supportive role during pregnancy in cows.