Uses of Milk Progesterone Test
If you are breeding cattle and you own a cattle farm, here is a way to have a higher success rate in breeding. Progesterone is known as the female sex hormone that aids in pregnancy. It is produced by the corpus luteum in the ovary. High levels of this hormone indicate a functional corpus luteum suggesting the high chance of getting pregnant. During the reproductive cycle, hormone levels rise and fall. It rises after estrus, if the cattle are not pregnant, the level goes down for 2 days and rises back again.
Progesterone levels in cattle milk help detect early pregnancy and understand estrous cycle. It allows cattle farmers to know when the right time to inseminate is and have a higher chance of success in breeding.
A milk progesterone test is done by collecting a milk sample from a cow. There are kits sold for this kind of test. There are two ways that this test can help farmers: 1) Test to confirm estrus and 2) as an early pregnancy detector.
Test to confirm estrus – A high level of progesterone means that the cow is not in estrus and is not ready for insemination. Low levels would suggest that a cow is near estrus but uncertain if it is the right time to inseminate. The test is most helpful in detecting those who should not be inseminated because having low levels of progesterone in milk may mean:
- The cow is near estrus or is already in estrus.
- The cow has inactive ovaries therefore it’s not cycling.
- Or the cow has ovarian follicular cyst.
Test as for Early Pregnancy – The milk sample should be collected after 21 to 24 days from estrus and insemination. Low progesterone level means the cow is not pregnant. High levels suggest that the corpus luteum is functional and the cow might be pregnant. This test is most helpful in detecting who is not pregnant because high levels may mean more than just being pregnant. It may also mean one of the following:
- The cow is pregnant.
- The cow is not pregnant but is in the middle of estrous cycle due to:
- Error in estrous detection thus wrong time to inseminate
- Longer than usual estrous cycle
- The cow was pregnant but embryo died.
- Abnormalities such as pus accumulating in the uterus or a dead, mummified fetus.
The milk progesterone test helps improve reproductive efficiency when it comes to cattle breeding. Either by detecting and taking note of their estrous cycle to know when to inseminate or in detecting pregnancy or abnormalities.




