An ultrasonographic method to study reproductive seasonality in ewes isolated from rams.

In studies concerning the seasonality in sheep, the effect of the teaser-ram, which can by itself induce oestrus as well as the development of ovary function bodies, has not been considered. In this study, a method is developed to determine ovarian activity during the year while excluding a possible influence of the ram. The study was carried out on 10 German Blackhead Mutton ewes (GBM) and 10 German Mutton Merino ewes (GMM) and lasted for 14 months.

[Influencing factors on the level of the ovulation rate in sheep during the main breeding season--an ultrasonographic study].

The main breeding season for sheep in Germany is from the beginning of September until the end of November. The aim of this study was to determine the factors which influenced the level of the ovulation rate (o. r.

The influence of the ovulation rate on ultrasonically determined ovine corpus luteum morphometry and progesterone concentrations in cyclic and early pregnant sheep.

The objective of the present study was to describe morphology and function of the Corpora lutea (CL) during the oestrous cycle and early pregnancy in sheep with different ovulation rates. In total 40 Booroola. Mutton Merino crosses [heterozygous carriers (FecBFec+) and non-carriers (Fec+Fec+) of the Booroola-fecundity gene (FecB)] with ovulation rates 1 to 4 were examined.