Real-time ultrasonic scanning in the diagnosis of pregnancy and the estimation of gestational age in cattle

Abstract

Diagnoses of pregnancy were made on 110 Hereford cross Friesian and 69 blue grey (white shorthorn cross Galloway) cows between 92 and 202 days after last service using a real-time ultrasonic scanning instrument with a 3.5 MHz rectal transducer. Of the 174 cows which subsequently calved, one was wrongly diagnosed as non-pregnant. Of the five cows which did not subsequently calve two were diagnosed as pregnant and may in fact have been pregnant at the time of scanning. The overall level of accuracy of pregnancy diagnosis was 98.3 per cent. In further trials with 16 Hereford cross Friesian and 16 blue grey cows scanned at regular intervals between 20 and 140 days of gestation, pregnancy was diagnosed with confidence from 30 days, and relationships were established whereby gestational age could be estimated from measurements of certain uterine and fetal dimensions. Crown-rump length provided the most precise estimate of gestational age (residual sd +/- 4.5 days) and uterine diameter the least (+/- 12.6 days) with head length and the diameters of trunk, head and nose being intermediate (+/- 6.9 to 8.7 days).

Ultrasonic Measurement of Fetal Parameters for Estimation of Gestational Age in Korean Black Goats

“…Aiumlamai et al [1] reported that coefficient value of fetal trunk diameter against gestational age in ewes was significant (r=0.80). White et al [22] reported that mean fetal trunk diameter was also highly correlated with gestational age in cattle (r=0.95). In this study, these high correlation of fetal trunk and gestational age was also demonstrated in Korean black goats (r=0.8876).…”

“…Luvoni et al [14] evaluated biparietal diameter, gestational sac and placental thickness for estimation of gestational age in the bitch. White et al [22] reported the relation of biparietal diameter, trunk diameter, crown-rump length and uterine diameter with gestational age in the cattle. These studies were also reported in the small ruminants.…”

Bovine Reproductive Ultrasonography: A Review

“…Using a 3.5 MHz transducer, they observed irregularly shaped nonechogenic structures in the lumen of the uterus from day 28 post-insemination. Later, several authors [72][73][74][75][76][77][78][79][80][81] reported on the use of ultrasonography to diagnose pregnancy in cattle.…”

“…Growth curves of fetal structures based on ultrasonographic fetometry have been reported [95,96]. Kähn [96] described in detail the sonographic fetometry of fetuses in 19 pregnant heifers.…”

Estimating fetal age: how accurate is it really?

“…Furthermore, simple correlation coefficients do not provide a means of comparing between measurements as they are affected by factors other than how well fetometry predicts age (Goodwin and Leech 2006). Nevertheless, almost all reports of fetometry and fetal age (from White et al 1985to Lazim et al 2016) have focussed on correlation and regression rather than accuracy. One study (Fitzgerald et al 2015), which claimed to have evaluated ultrasonography as a predictor of gestational age, just reported mean difference between predicted and actual values, with no measure of precision at the individual cow level.…”