Shearing Stress in Pregnant Ewes I. Progesterone Level

D. GUDEV, E. KISTANOVA, I. ALEXIEV and S. ALEXANDROV

Research Institute of Animal Science, BG-2230 Kostinbrod, Bulgaria

Abstract

GUDEV, D., E. KISTANOVA, I. ALEXIEV and S. ALEXANDROV, 1999. Shearing stress in pregnant ewes. I. Progesterone level. Bulg. J. Agric. Sci., 5: 647-650

An experiment involving 19 Danube merino ewes was carried out. The ewes were allocated into 3 groups as follows: Ist group -shorn before insemination, IInd group-shorn at one month after the insemination and IIIrd group shorn at 1.5 months before parturition.
The effect of shearing on progesterone dynamics in ewes was studied. It was established that shearing of sheep before the insemination has no effect on progesterone level determined 1.5 months after the insemination. Shearing of sheep both at the beginning and at the end of pregnancy had a definite stimulatory effect on progesterone level determined at 3.5 and 4.5 months of pregnancy respectively. The physiological meaning of shearing induced enhancement of progesterone level was interpreted in the light of the recent studies concerning the inhibitory role of progesterone on glucocorticoid-dependent aromatase.

Key words: ewes, shearing stress, progesterone, pregnant