St. YOTOV, M. DIMITROV and N. VASSILEV
Trakia University, Faculty of Veterinary Medicine, Department of Obstetrics, Gyneacology and Andrology, BG - 6000 Stara Zagora, Bulgaria
YOTOV, St., M. DIMITROV and N. VASSILEV, 2005. Early pregnancy diagnosis and examination of embryofoetal growth in the Local ovine breed. Bulg. J. Agric. Sci., 11: 119-124
The aim of the present study was to determine the most convenient time for early pregnancy diagnosis via transrectal ultrasonography and to follow out the changes occurring in the embryonic growth in relation to gestational age in a local ovine breed. The study was performed on 28 Trakia Merino sheep, aged 3-5 years and weighing 55-60 kg. The animals were artificially inseminated after synchronization of the estrus by intravaginal sponges Chrono-gest (Intervet, International B.V., Boxmeer, Netherlands) and eCG (Folligon, Intervet International B.V., Boxmeer, Netherlands). At post insemination days 20, 25, 30, 35 and 40, a transrectal ultrasonographic study with "Aloka" SSD 500 Micrus (Co. Ltd, Tokyo, Japan) equipment and a 5 MHz linear transducer was performed. The first day after the insemination was accepted as beginning of the pregnancy. The pregnancy was detected on the basis of presence of an enlarged uterine lumen with amniotic fluid; presence of an embryo; detection of heart activity and visualization of placentomas. The size of the embryo (mm) at post insemination days 25, 30, 35 and 40 were measured. Using program StatSoft 1984-2000, Ink. (Copyriht Y 1990-1995 Microsoft. Corp.). The analysis of variance (ANOVA) and the least significance difference (LSD) as a post-hoc test statistically processed the results. The results showed that, in Trakia Merino sheep breed the most convenient time for early pregnancy diagnosis and elimination of embryonic death via transrectal ultrasonogrsphy and 5 MHz probe was at post insemination day 30. The received values of embryo size were a positive correlation (r=0.79) with gestational days and could be used to estimation of gestational age.