Basal and estradiol-induced release of gonadotropins in dairy cows with naturally occurring ovarian cysts.

A study was conducted to identify relationships between serum sex steroid concentrations and release of gonadotropins in dairy cows with ovarian cysts. Cows with ovarian cysts were grouped according to sex steroid profiles as being under estrogenic (n = 6) or low steroid (n = 6) influence. All cows were submitted to a sampling and treatment protocol to 1) record basal pulsatile release of gonadotropins and 2) determine whether luteinizing hormone (LH) or follicle stimulating hormone (FSH) was released after sequential administration of exogenous estradiol and gonadotropin releasing hormone (GnRH) treatments were given 30 h apart.