Serum testosterone and estrogen concentrations in the Holstein-Friesian bull after successive ejaculations.
The testosterone and estrogen concentrations in venous serum of 4 mature Holstein-Friesian bulls were determined by radioimmunoassay before and after each of 3 consecutive semen collections taken at 1-hour intervals. The hormonal concentrations were highly variable for the 2 steroids, but uniform in their patterns after the bulls had ejaculated. After the 3rd semen collection, marked changes in hormonal concentrations did not occur.
D000818:Animals; D002417:Cattle / Q000097:blood / Q000502:physiology*; D004542:Ejaculation; D004967:Estrogens / Q000097:blood*; D008297:Male; D013739:Testosterone / Q000097:blood*; D013997:Time Factors
D004967:Estrogens; D013739:Testosterone