Ultrasound Diagnostics of Late Embryonic and Foetal Death in Three Sheep Breeds

The aim of the present study was to investigate the possibilities for diagnostics of late embryonic and foetal death in different sheep breeds and to determine the effect of gestational stage and the parity. The experiment was performed with 209 Trakia merino; 211 Pleven blackhead and 85 Ile de France sheep. A pregnancy diagnosis was determined by single echographic examination in the period between the 20th and the 50th gestational days via ultrasound equipment. The sheep were divided into groups according to the gestation stage and the parity. The results were compared to birth records data and statistically processed. The analysis of results showed that the single echography could be successfully used for diagnostics of late embryonic and foetal death. The gestational stage correlated negatively (p < 0.05) with embryonic/foetal losses. Embryonic deaths occurring betweens gestational days 20 and 40 were statistically significantly more (p < 0.05) than foetal deaths. The risk for death of the embryo, resp. the foetus between the 20th and the 50th gestational days was higher in sheep that have already given birth. In conclusion, late embryonic and foetal death could be detected effectively with a single ultrasonography between the 20th and the 50th gestational days. The optimization of the rearing technology during the first 50 days after the insemination could substantially improve the reproductive performance in sheep.