[Ultrasonographic examinations of fetal growth of sheep between day 20 and day 50 of gestation]. / Ultrasonographische Messungen zum fetalen Wachstum des Schafes zwischen dem 20. und 50. Trächtigkeitstag.

Previous studies on embryonic and fetal growth in sheep were mostly transversal using animals killed at various stages of gestation. Until now it was difficult to monitor the development of individual embryos/foetuses during pregnancy, especially during the first and second pregnancy month. Real-time ultrasound as a non invasive method could be an appropriate method for examination of embryonic and early foetal development in sheep. The aim of this study was to determine the embryonic and foetal development of the crown-rump-length (CRL) in pregnant ewes in relation to the number of fetuses and/or the breed. Between the 20th and 50th day of pregnancy the embryos/foetuses showed an exponential growth which can be best described by the equation of the form CRL (mm) = W * exp (k * day of pregnancy). The individual variability in embryofetal growth is in part due to the number of embryos per sheep and the sheep breed.

[Ultrasonographic examination of the placentoma development in pregnant sheep]. / Ultrasonographische Untersuchungen zum Plazentomwachstum beim trächtigen Schaf.

The aim of this study was to determine the in vivo development of the placentome diameter during the pregnancy in sheep. 32 ewes of four different breeds were involved. After the first detection of the placentomes (28 day p. c.) the ewes were scanned by transrectal ultrasound (Aloka SSD 500, 5 MHz linear probe) in a standing position every second or third day until day 50 p. c. and after the every week until parturition. The maximum diameters of 10 placentomes were measured. The placentome diameter increased rapidly until the middle of the third pregnancy month followed by a slight decrease. Between the 110th day p. c. and the parturition the diameter was nearly constant, but 40% of the animals showed a second increase at this time. The placentome diameter could be a good mark to describe the function of the placenta in sheep but it is only stipulated fit for the diagnosis of the state of the pregnancy.

[Real-time ultrasonic pregnancy diagnosis (B-mode) in sheep. 1. Frequent examinations during the first month of pregnancy]. / Die ultrasonographische Trächtigkeitsdiagnostik (B-Mode) beim Schaf. Teil 1: Verlaufsuntersuchungen im ersten Trächtigkeitsmonat.

Transrectal ultrasonography was performed on 63 ewes (four breeds) to determine the earliest day at which pregnancy, the first embryo, the number of embryos, the embryonal heartbeat and placentoms could be detected. The ewes were examined at intervals of two to three days on day 12/13 to 30 post breeding. An Aloka SSD 500 ultrasound unit was used with a 5-Mhz probe. The diagnosis of the pregnant ewes took place on day 17.6 +/- 1.8 p.c. The first embryo was detected on day 20.5 +/- 1.9 p.c., but not all of the embryos were counted accurately until day 26. The heartbeat of the embryos was detected on day 22.9 +/- 2.9 p.c. and placentoms on day 27.6 +/- 2.4 p.c. The influence of the breed on the results will be discussed. The proportion of sheep with a loss of embryos was 24.6% (partial loss of embryos 18.0%, total loss of embryos 6.6%). In conclusion, transrectal ultrasound is a good method to describe the early pregnancy in sheep.