| Abstract: | Testosterone in plasma was measured by radioimmunoassay in cows with ovarian cysts and in cows during the estrous cycle. Concentrations of testosterone in plasma (60.8 +/- 2.7 pg/ml; mean +/- standard error) in cows with ovarian cysts were variable but within the range in cows during the estrous cycle. Mean concentrations of testosterone in plasma increased from 46.3 pg/ml at estrus to 85.1 pg/ml on day 13 of the estrous cycle. In cows with ovarian cysts, concentrations of testosterone in plasma declined within 24 h following prostaglandin F2 alpha and tended to increase by 9 days following gonadotropin releasing hormone. The role of testosterone in estrual behavior and inhibiting resumption of ovarian cycles is likely minimal. |
