Progesterone, a natural hormone that circulates in the cow's blood and is also found in the milk, is produced by the corpus luteum (CL) after ovulation and fluctuates during a normal estrous cycle. Progesterone levels accurately reflect the different stages of the estrous cycle.
Testing progesterone about 20 days after insemination can identify open cows by a bright blue result . The open cows can then be rebred. If progesterone levels are high, the cow is pregnant.
Identifying open cows earlier will reduce the days open and lower costs.
