Eficiency of pregnancy diagnosis in ewes by transrectal and transvaginal ultrasonography

This work was conducted with the objective to test the viability of ultrasound diagnosis of gestation in sheep (n = 145) by transrectal and transvaginal via, comparing their efficiency using, respectively, linear (6.0 and 8.0 MHz) and micronconvex (5.0 and 7.5 MHz) transducers. The ultrasound examinations, performed by the same operator and with the female contained in station position, were carried out in different periods of the gestation. In Group I, the females (n = 30) were in the 15th and 29th day of gestation, in Group II (n = 28) between days 30th and 59th, in GIII (n = 35) between days 60th and 89th, in GIV (n = 32) between 90th and 139th and the GV (n = 20) were formed by empty females. The average time, in seconds, used for the accomplishment of the gestation diagnosis by transrectal and transvaginal examinations, respectively, was 9.02 +/- 5.47 and 11.73 +/- 6.94 in the GI, 13.89 +/- 16.20 and 11.36 +/- 11.98 in GII, 56.07 +/- 40.61 and 128.32 +/- 64.36 in GIII, 5.33 +/- 3.35 and 2.66 +/- 1.82 in GIV and 14.26 +/- 17.21 and 20.35 +/- 17.71 in GV. It was registered that the transrectal examination was faster in the GI, GIII and GV, slower in the GIV and equal in GII. The results permit us to conclude that the diagnosis of gestation in sheep can be carried out by transrectal and transvaginal examinations, being up to the operator to define which of them visualize the best image in each one of the gestational phases.