[The relation between the concentration of testosterone in seminal plasma and certain indicators of reproduction in roosters].

Testosterone concentrations in the semen plasma of the cocks of the laying type were analyzed. The levels in semen plasma were substantially lower than in peripheral blood and were found at the interval of 1.58 to 13.30 nmol . 1(-1), the average values amounted to 5.5 nmol . 1(-1). At the repeated samplings of the same animals, considerable variability of hormone levels was observed, which suggested a possibility of the pulsation character of the changes in the androgen also in this biological material. The correlation coefficients between the testosterone levels in semen plasma and ejaculate volume, as well as between the sperm concentration were positive, however, statistically insignificant. The relation between testosterone and the weight of testes was at the significance limit.