A study of serum steroid hormones concentrations of pregnant cows

الملخص EN

The objective of present work is to estimated peripheral blood serum concentrations of pregnancy hormones, oestradiol, progesterone and testosterone, in cows .

For this purpose 24 Frezain-Holstein cows at different stages of pregnancy the blood samples were taken from jugular veins.

The serum were separated and frozen at–20 c until analysis.

The serum hormones were measured by a specific ELISA technique (ELISA Linear Multi Reader).

The data were represented Mean + S.D.

Progesterone was high during pregnancy reaching a maximum of 91.94 + 26.09 ng / ml during last thirds (6-8 months) of pregnancy , but was below 9.12 + 2.41 ng / ml for several months during the pregnancy.

Oestradiol levels varied from 9.0+ 2.89 pg/ml in the first thirds of pregnancy to 282.6 + 48 .514 pg / ml during the last month of gestation.

While testosterone hormone level was low 0.32 + 0.12 ng /ml during pregnancy.

The result indicated that the major sources of hormones appeared to be the 0vary (corpus luteum) and the uterus (placenta).

The ovarian contribution was greater during the first–thirds of pregnancy than later, whereas that made by the placenta was higher during the last thirds of pregnancy.