Saisonale Einflüsse auf die Konzentration von Progesteron im Blutplasma von Müttern der Rasse Schwarzköpfiges Fleischschaf (Kurzmitteilung)

Abstract. Title of the paper: Seasonal influences on blood plasma progesterone concentration in ewes of Black head Mutton sheep breed (short communication)
In 71 Black head mutton sheeps on pasturing and housing were determined from the year 1995 to 1997 and there in the period from March to October the concentration of blood progesterone for determination of onset of estrus. The level of blood progesterone reported, on literature also, no cycle on this period. The investigation of 6 of this sheeps with ultrasonography had the result of ovarian activity with follicles from 2 mm to 7 mm in diameter, but no cycle was determined.

The progesterone level of minimum and maximum on all years differed from March to beginning of September between 0,33 ng/ml and 2,15 ng/ml blood progesterone, after this to October between 0,82 ng/ml and 4,25 ng/ml blood progesterone.

The pregnant sheeps detected blood progesterone concentrations from 5,50 ng/ml to 13,55 ng/ml blood progesterone (twins). The corpus luteum activity may be is prevalent on the blood progesterone level up 2 ng/ml and pregnancy up 5 ng/ml blood progesterone.

The detectability of blood progesterone and supplemented ultrasonography of ovary possess the possibility recording of onset cycle activity and early pregnancy diagnosis.