The use of real-time ultrasonography to select embryo donors participating in a transgenesis goat programme

The efficiency of the transrectal real-time ultrasonography (RTU) scanning technique to monitor the number of corpora haemorraghica (CH) of goat embryo donors was compared to results obtained by a reference method (laparotomy). The ovaries of 24 Saanen goats were observed by RTU, approximately 72 h after superovulatory treatment, followed by laparotomy. The diameter of the four largest CHs was measured using image analysis software. The use of ultrasonographic scanning allowed in determining if a goat had ovulated or not in all the females. In all the ovaries examined the total number of CHs counted was lower (p < 0.01) with RTU than following the laparotomy method. The correlation coefficient between the number of identified CHs detected by the two methods was significantly positive (r2 = 0.71; p < 0.001). The sensitivity, specificity and total efficiency of the ultrasonographic observation to determine the occurrence of ovulations in a goat was 100.0%. However, the sensitivity to determine the presence of multiple ovulations was only 25.0%, but the specificity remained 100.0%. The mean diameter of the four largest CHs per ovary following superovulation was 6.88 ± 0.22 mm. In conclusion, assessment of the ovulatory response by transrectal RTU can be used to select responding goat donors in a transgenesis programme or to evaluate a donor with multiple ovulations, but not to establish the exact number of CHs.