Dr. Tom Van Dyke By Dr. Tom Van Dyke Reproduction is one of the
most important aspects to any dairy operation, so the smallest
improvements can mean big returns. Any chance to help improve
breeding is an opportunity. One of the major causes of
reproductive failure reported on farms is ovarian follicular
cysts.1 Ovarian cysts can cause over expression of heat,
irregular cycling and can cause the cow to become infertile.2 A
treatment of GnRH can help keep ovaries healthy by clearing out
these ovarian cysts that may be standing in the way of getting a
cow pregnant. In a 2007 study of dairy producers, almost 70%
reported having instances of cystic ovaries occur in their
herd.3 This condition is estimated to affect at least 1 million
dairy cows in the United States annually.2 It also is a major
cause of infertility and economic loss on farms because cows are
infertile as long as the condition persists.2 Ovarian cysts
occur when a follicle has persisted more than 10 days and has
become larger than two centimeters i