The Level of Plasma Testosterone during the Prenatal and Postnatal Period of Development in Bulls

Abstract

Kozumplik J.: The Level of Plasma Testosterone during the Prenatal and Postnatal Period of Development in Bulls. Acta vet. Bmo 50, 1981: 27-32. In order to establish testosterone in the blood plasma we employed the direct radioimmunological method with testosterone-labelled tritium. An examination of 44 fetuses was carried out during the prenatal period from the 190th to the 288th day of intrauterine development. On average we ascertained values of 1,145 ± ± 0,73 nmol/l, without any obvious relation to the age of the deVeloping fetus. In the postnatal period an assessment was made of 57 bulls aged 47 to 106 days, and approximately 2,25 ± 1,46 nmol/l plasma testosterone was ascertained, ii: 23,04 ± ± 19,81 nmol/l in 108 bulls aged 7 to 13 months, and 21,791 ± 14,78 nmol/l in 154 bulls aged 2 and more years. The difference between the mean value of plasma testosterone in the prenatal period compared with all the assessed age categories in the postnatal period was significant (P < 0,01). In bulls aged 47 to 106 days the mean value of plasma testosterone compared with the values of other age cate:' gories, was also significantly lower (P < 0,01).