Sixty-two dairy cows diagnosed as having cystic ovarian degeneration were used to study the correlation between rectal palpation findings and plasma
progesterone concentrations and the response of
cysts to treatment using
fenprostalene, a
luteolytic agent. Rectal palpation accurately determined the presence of luteal
cysts as confirmed by plasma
progesterone concentrations of 3 ng/mL or more. Treatment with
fenprostalene was very effective for luteal
cysts: a high percentage of treated cows exhibited estrus within seven days
after treatment. The conception rate following artifical insemination during the induced estrus was 87.5% (21/24). Rectal palpation was much less accurate for the diagnosis of
follicular cysts. Cows diagnosed as having
follicular cysts had wide variations in plasma
progesterone concentrations. Response to
fenprostalene treatment was poor in cows with nonluteinized cystic follicles associated with low
progesterone concentrations. However, cows diagnosed as having
follicular cysts, but with
progesterone concentrations of 1 ng/mL or more, responded better to
fenprostalene treatment than cows with low
progesterone concentrations.It was concluded that, if correctly diagnosed, luteal
cysts can be successfully treated with
fenprostalene, and conception rates following treatment can be expected to be normal.