title: Gonadotropin releasing hormone treatment of dairy cows with ovarian cysts. I. Gross ovarian morphology and endocrinology.
abstract: Dairy cows diagnosed as having ovarian cysts were assigned to receive either sterile water or 100 mug GnRH (5 cows/group). Immediately prior to treatment and three days post-treatment, ovaries were observed via paralumbar laparotomy, photographed and visible structures and ovarian size recorded. Nine to thirteen days post-treatment, ovaries were removed. Blood plasma was collected for hormone determinations prior to each surgery, 1.5 and 3.0 hours and 1, 5 and 9 days post-treatment. Although concentrations were similar between groups prior to treatment, concentrations of progesterone were higher and LH and estradiol-17beta lower for GnRH treated cows than control cows, immediately prior to ovariectomy. A layer of luteal tissue approximately 5 mm thick was present around the periphery of the cystic structure at ovariectomy in 4 of 5 GnRH treated cows, but in only one control cow. The thickness of the luteal layer around the periphery of the ovarian cysts was correlated -.82, .78 and -.63 with estradiol-17beta, progesterone and LH, respectively. In summary, response to GnRH treatment in cows with ovarian cysts appears to be characterized in most cases by luteinization of the cystic structures.
authors.affiliation: Department of Animal Science University of Illinois Urbana, Illinois 61801 USA.
authors.forename: D J
authors.initials: DJ
authors.lastname: Kesler
authors.forename: R G
authors.initials: RG
authors.lastname: Elmore
authors.forename: E M
authors.initials: EM
authors.lastname: Brown
authors.forename: H A
authors.initials: HA
authors.lastname: Garverick