[Real-time ultrasonographic pregnancy diagnosis (B-mode) in sheep. 3. Determination of the number of embryos and fetuses]. / Die ultrasonographische Trächtigkeitsdiagnostik (B-Mode) beim Schaf. Teil 3: Untersuchungen zur Erfassung der Anzahl von Embryonen und Feten.

Transrectal ultrasound examination was performed once in 1159 German Mutton Merino ewes in a standing position using a 5.0 MHz linear array transducer (group 1), 505 German Mutton Merino ewes were restrained in dorsal recumbency while scanned transrectally using a 7.5 MHz probe (group 2). Referring to actual number of lambs born the prepartal prediction of fetal number was correct in 71.8% (group 1) and 78.6% (group 2) of the ewes from days 17 to 69 p.c. The highest accuracy for determining fetal number (89.1%) was in group 1 at days 35 to 46 of gestation. In group 2 the accuracy was more consistent over the whole period of examinations and reached over 80% from as early as 29 days p.c. As litter size increased, examinations in both groups became increasingly inaccurate in determining correct litter size. A subdivision of living, underdeveloped and dead embryos or foetuses was possible by the presence or the absence of a heartbeat and the crown-rump-length of the embryos or foetuses. The percentage of ewes with embryonic or fetal loss is given.

[Ultrasonic pregnancy diagnosis (B-mode) in sheep. 2. Comparative studies using transcutaneous and transrectal pregnancy diagnosis]. / Die ultrasonographische Trächtigkeits-diagnostik (B-Mode) beim Schaf. Teil 2: Vergleichende Untersuchungen zur transkutanen und transrektalen Trächtigskeitsdiagnostik.

The aim of this study was to check the earliest time for the ultrasonic pregnancy diagnosis in flock management of sheep after finishing the mating season. Therefore a transcutaneous pregnancy diagnosis (5 MHz) took place on a total of 1060 German merino-mutton sheep between day 10 and 90 after mating (a.m.) and a transrectal diagnosis (5 MHz) took place on a total of 1442 German merino-mutton sheep between day 10 and 70 a.m. At the beginning of the third week a.m. the accuracy of transrectal diagnosis was over 95% and increased to 100% on day 35 a.m. At that time the accuracy of transcutaneous diagnosis was 80% and reached 100% on day 60 a.m. Considering the reached accuracies the pregnancy diagnosis should not take place before day 35 after the end of the breeding season. After day 35 a.m. it is advisable to combine the transcutaneous and the transrectal pregnancy diagnosis. That means that at first all animals are examined by transcutaneous sonography and in the second step the so-called "non-pregnant sheep" are checked by transrectal ultrasound. From the beginning of the third month a.m. a single transcutaneous pregnancy diagnosis is sufficient.