Early Pregnancy Diagnosis using Trans-Abdominal Ultrasonography in West African Dwarf Goats
The purpose of this study was to determine the earliest time pregnancy could be detected and the accuracy of pregnancy diagnosis in the West African Dwarf goat using trans-abdominal B-mode real-time ultrasonography. Seventeen does of varying parities (allotted to 2 groups; group 1 = 12 and group 2 = 5) and a buck of proven fertility were used for this study. The group 1 does were hand-mated following synchronized estrus while does in group 2 were left in the company of the intact fertile buck. Trans-abdominal scanning using an ultrasound machine equipped with a transducer of multiple frequency (5.0 to 8.0 MHz) was carried out every day in the group 1 does starting from Day 15 (Day of estrus/ breeding = day 0 of gestation) to Day 40 and, thereafter, every other day to Day 60 of gestation. Ultrasound scan of the group 2 does was undertaken randomly until confirmed pregnant. Acoustic coupling gel, Wavelength® was liberally applied on the animal skin area to be scanned. Sonograms were printed using UP 897MD thermal printer on Sony ultrasound paper; UPP110S. The earliest sonographic evidence of pregnancy was the imaging of circumscribed anechoic fluid in the uterus (EV) on Day 18.8 ± 0.29 and the embryo on Day 20.2 ± 0.24. Heartbeat was detected in the embryos on Day 23.8 ± 0.91, embryo cephalization and development of limb buds on Day 31.4± 0.88, and the appearance of placentomes on Day 34.4 ± 0.42 of gestation. Fifteen (ten from group 1 and all 5 from group 2) does (88.24%) were diagnosed pregnant by ultrasonography. All pregnant does subsequently kidded. The kids were born alive with no apparent morphological abnormalities. The computed average gestation length using the group 1 does was 144± 0.12 days.
Key words: Pregnancy detection, accuracy, ultrasound, WAD goat.