Pregnancy Dagnosis in Sheep: Review of the Most Practical Methods

Abstract

Various practical methods have been used for pregnancy diagnosis in sheep. Both pregnancy and fetal numbers are accurately diagnosed by using radiography after day 70 of gestation. Rectal abdominal technique detects pregnancy with an accuracy of 66 to 100% from d 49 to 109 of gestation, however, it has a low (17 to 57%) accuracy for determining multiple fetuses. Progesterone assays have a high sensitivity (88% to 100%) and a low specificity (60% to 72%) at d 16 to 18. Estrone sulphate assay accurately detects pregnant ewe at d 30 to 35. Ovine pregnancy specific protein B (PSPB) assay accurately (100%) detects pregnancy from d 26 after breeding onwards. The accuracy of progesterone, estrone sulphate and oPSPB assays for determining fetal numbers is relatively low. A-mode and Doppler ultrasonic techniques accurately detect pregnancy during the second half of gestation. Fetal numbers cannot be determined by A-mode ultrasound, while the Doppler technique needs experience to achieve high accuracy. Transrectal B-mode, real time ultrasonography identifies the embryonic vesicles as early as d 12.8 after mating, but the sensitivity of the technique for pregnancy is very low (12%) earlier than 25 d after mating. Transabdominal B-mode ultrasonography achieved high accuracy for pregnancy diagnosis (94% to 100%) and the determination of fetal numbers (92% to 99%) on d 29 to 106 of gestation. Realtime, B-mode ultrasonography appears to be the most practical and accurate method for diagnosing pregnancy and determining fetal numbers in sheep.

CIDR and Ultrasound-Fetometry Scan; Comparative Study Between Sheep and Goat in Egypt

“…In the present study, the first sign of pregnancy in ewes and does was the presence a circular or elongated echogenic structure located in uterus cranial to the urinary bladder on day 21 post service. These results agreed with the previous findings which has been reported by Karen et al, (2001) either. Those studies explained that the body of the uterus was imaged usually over the urinary bladder but it was also found anterior or dorsal to the bladder in the non-gravid or early pregnant ewes.…”

Pregnancy diagnosis techniques in goats – a review

“…Their work principle is based on ultrasound wave reflection that determines the boundaries of organs filled with fluid, such as the pregnant uterus. The type A apparatuses possess a good sensitivity and specificity, exhibiting an accuracy of 80-85% between the 60 th and 120 th post breeding days (Dawson, 2002), but the proportion of false positive diagnoses could be considerable when the urinary bladder is full or in some inflammatory uterine diseases (hydrometra, pyometra) (Haibel, 1990;Karen et al, 2001).…”

“…The selection of a method depends on the stage of gestation, method's precision and the available equipment at the farm (Gonzalez et al, 2004). From the point of view of their practical application potential, Karen et al (2001) divide the methods for pregnancy diagnosis in goats to less practical (non-return to oestrus, transabdominal palpation, laparoscopy, laparotomy, palpation of the caudal uterine artery, rosette inhibition test) and widely used (radiography, rectoabdominal palpation, hormonal assays, assay of pregnancy proteins, ultrasonography).…”

Biodiversity of multiple Pregnancy-Associated Glycoprotein (PAG) family: gene cloning and chorionic protein purification in domestic and wild eutherians (Placentalia) – a review

“…The presence of PAGs can be measured by radioimmunologic (RIA) and immunoenzymatic (ELISA) tests. These PAG tests allow for early pregnancy diagnoses in domestic cattle [69,80,91,[95][96][97][98], sheep [70,[99][100][101][102][103][104] and goats [105,106]. Moreover, heterologous PAG tests were also useful for pregnancy diagnoses in wild ruminants, i.e.…”