Comparative efficacy of trans-rectal and trans-abdominal ultrasonography for early diagnosis of pregnancy and embryonic ageing in goats

Abstract

A study was conducted on 24 Kokan Kanyal goats to compare the efficacy of trans-rectal (TR: linear, 6 to 8 MHz probe) and trans-abdominal (TA: sector, 3.5 to 5.0 MHz probe) ultrasonography (USG) for diagnosis of early pregnancy. The goats with known mating history were scanned thrice by USG between 20 to 23, 25 to 28 and 35 to 38 days of gestation. Attempts were made to detect embryonic vesicle, embryo proper, embryonic heart beat, amniotic membrane, placentomes and crown-rump length (CRL) by electronic caliper of USG machine. Comparatively, the TR probe was found more efficient as it detected the early embryonic vesicles and embryonic heart beat at 20 to 23 and 25 to 28 days post mating as compared to 25 to 28 and 35 days onwards, respectively by TA transducer. The mean CRLs of embryos were recorded as 5.84±0.38, 12.32±0.68 and 27.09±1.55 mm at 20 to 23, 25 to 28 and 35 to 38 days of gestation, respectively. The overall accuracy of pregnancy diagnosis by TR USG was 95.83% at 20 to 23 days of gestation which improved to 100% between 25–28 days of gestation and afterwards. With trans-abdominal scanning, the overall accuracy of pregnancy diagnosis was only 45.83% at days 20 to 23, 87.50% on 25 to 28 days and 100% on 35 to 38 days of gestation. TR scanning diagnosed the pregnancy with 100% accuracy as early as 25 days of gestation in goats.