Anotace:
The artificial insemination and the oestrus cycle synchronization are some of the most frequently used biotechnical methods of reproduction not only for sheep, but also for the other spieces of livestock. They are used mainly to achieve the shortening of the lambing period and to achieve easier breeding. An exact estimation of the lambing period is essential for the breeding process optimization, as it allows better preparation for the lambing period. This experiment monitors 48 Zwartbles sheep. Before the artificial insemination itself, the oestrus cycle of the sheep was synchronized using intravaginal sponges Ovigest and the subsequent intracervical insemination was performed using fresh, diluted and chilled semen extracted from rams of the Zbyšek and Zachari lineages. The pregnancy rates after insemination and after the subsequent breeding of the barren ewes in a harem were determined according to the pregnancy detection and the subsequent lambing times. Marking the exact date and time of insemination and lambing allowed to determine the overall pregnancy lengths in the inseminated animals. The overall pregnancy rate after insemination was 41.7% and the overall pregnancy rate after the subsequent breeding in a harem was 93.8%. The overall pregnancy period in animals after insemination varied between 141.6 and 147.8 days and the peak of lambing took place between 144.1 and 146.8 days.