Early diagnosis of pregnancy in sows by ultrasound evaluation of embryo development and uterine echotexture

Two operators attempted to detect pregnancy ultrasonographically in 196 sow s daily from 15 to 25 days after insemination; 20 unbred sows were also inv estigated. The probe was applied transcutaneously on the right abdominal wa ll near the last three mammary glands. During each examination, the embryos were visualised and their transverse and longitudinal dimensions were meas ured. Pregnancy was confirmed by an ultrasonographic detection of embryos f ive days after the first ultrasound diagnosis and finally 30 to 32 days aft er insemination. The accuracy of diagnosis was less than 83 per cent on day s 15. 16 and 17 but improved to more than 90 per cent from day 18 onwards. The uterine echotexture was studied in seven sows at oestrus and 15, 17, 19 , 21, 23 and 25 days after insemination. The echotexture was more homogeneo us from days 15 to 25 after insemination than at oestrus.