Determination of the Number of Fetuses in Sheep by Means of Blood Progesterone Assay and Ultrasonography

The studies were carried out on 45 sheep during the reproductive season. A programmed artificial insemination was performed, after synchronization of the estrus with vaginal sponges Chronogest, and treatment with Folligon. Progesterone analysis and transrectal examination were accomplished on the day of insemination, 20, 40, and 60 days afterwards. It was determined that on the 60 day of pregnancy, the level of progesterone in sheep carrying two foetuses (26.9 ± 5.0 ng/mL) was higher (p<0.01) compared to that in sheep carrying just one foetus (20.1 ± 3.0 ng/mL). The specificity of the transrectal ultrasonography (84.2%) by the 40 day of pregnancy was higher (p<0.05) than that of the progesterone assay (66.5%). The summarized data showed that measuring the progesterone levels by means of ELISA on the 20 day after insemination could be used with success for diagnostics in pregnant and non-pregnant sheep. The determination of the number of foetuses in the studied sheep breeds through ultrasonography could be performed earlier (40 day), compared to that by progesterone method (60 day).