What hormone is known as the "pregnancy hormone" in livestock?

Progesterone is often referred to as the "pregnancy hormone" in livestock because it plays a crucial role in the maintenance of pregnancy. This hormone is secreted primarily by the corpus luteum in the ovaries and is essential for creating an optimal environment for embryo development. It helps to prepare the uterus for implantation and decreases the likelihood of uterine contractions, which could lead to an early termination of pregnancy.

During pregnancy, progesterone levels rise significantly, supporting gestation by inhibiting ovulation and maintaining the uterine lining. Its presence is critical for sustaining pregnancy in many species, making it a key hormone in reproductive physiology in livestock.

While testosterone, oxytocin, and FSH all have important roles in reproduction, they do not fulfill the specific function of maintaining pregnancy as progesterone does. Testosterone is involved in male reproductive development, oxytocin is known for its role in parturition and lactation, and FSH is crucial for the growth and maturation of ovarian follicles. Thus, progesterone's unique role firmly establishes it as the hormone associated with pregnancy.