Problems have been reported on farms with infections across the entire range. Cutting the grass for hay does not destroy the endophyte or reduce the alkaloid content or effect. The fungus lives within the plant and cannot be detected visually, however, you can test fescue for the level of endophyte infection. While the mechanism that causes the reproductive problems is not absolutely known. It is thought that an alkaloid resulting from the endophyte infection causes an excess production of a neuro-active chemical, dopamine.
Excess dopamine has a suppressing effect on the reproductive hormone, prolactin.
Prolactin is essential to the final stages of pregnancy and birth. Without the prolactin signal, the mare's body does not realize it is time to foal. There are no easy solutions to the fescue problem for broodmare owners. Monitor udder development and the foaling process. Test to see if you have an endophyte problem.