Relationship of peripheral estrogens and testosterone concentrations to sexual behavior in normal and cystic cows.

Peripheral estrogens and testosterone values on each day of the estrous cycle in the plasma of normal cows (n=6) were compared to those in single serum samples from cystic animals. The highest plasma testosterone was detected on the day before estrus (day 20), and estrogen peaks were observed on days 16 and 20. Serum from cows (n=125) with cystic ovarian degeneration, previously classified as either anestrous or nymphomaniac, was assayed only for either estrogens or testosterone. Additional serum samples were collected from 39 cystic cows to measure both steroids. Almost all of the results from cystic animals were within or below the ranges recorded in the normal cows. No significant differences for either steroid was found between the anestrous or nymphomaniac groups (P>.05). Therefore, it was not possible to demonstrate any relationship between either hormone or behavioral pattern.