Testosterone concentration in the seminal plasma of cocks

Abstract
1. Testosterone concentrations in the seminal plasma of cocks ranged from 0–46 to 505 ng/ml and were substantially lower than in blood plasma. 2. No significant variation was noted in seminal plasma testosterone concentrations during the light phase of the day, whereas the concentration in blood declined over this period. 3. Spermatozoal concentration and seminal testosterone decreased in the third sample of the semen collected sequentially at 3 h intervals. 4. Testosterone concentrations in seminal plasma (1.57 ±017 ng/ml) and in the semen from the ductus deferens (1–34 ±0.24 ng/ml) were not significantly different.