A Profile of Progesterone in Turkey Sera

Progesterone concentrations in the sera of immature and mature Large White hen turkeys were correlated with egg production, percent fertility and duration-of-fertility. Progesterone concentrations in normal and castrated Broad Breasted Bronze males were also determined. The radioimmunoassay procedure was used for the measurement of the sera progesterone. There was a decline in average egg production from 59.0% in February to 44.7% in May. Fertility declined as the season progressed from 79.7%, 63.5% to 51.8% for each of three consecutive duration-of-fertility trials. In each trial all hens were inseminated twice within a week and the average number of days hens remained fertile in each trial was approximately 38, 32 and 16 respectively. Progesterone concentration in the hens’ sera after sexual maturity was higher than before sexual maturity. Progesterone reached a peak concentration at 41 weeks of age at which point egg production was also the highest. Average progesterone concentration in toms after sexual maturity was higher than before. Progesterone was also detected in castrated males.