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A comparison of six methods used for detecting pregnancy in sheep
Author(s) -
WATT B. R.,
ANDERSON G. A.,
CAMPBELL I. P.
Publication year - 1984
Publication title -
australian veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.382
H-Index - 59
eISSN - 1751-0813
pISSN - 0005-0423
DOI - 10.1111/j.1751-0813.1984.tb07167.x
Subject(s) - udder , gestation , pregnancy , zoology , biology , medicine , obstetrics , pathology , mastitis , genetics
SUMMARY The speed and accuracy of 4 ultrasonic devices (Scanopreg®, Pregmatic 3®, Medata® external probe and Medata® rectal probe) were compared with udder scoring and harnessed vasectomised rams as methods of pregnancy diagnosis in 177 ewes, 59 of which were non‐pregnant. When using the Scanopreg® in ewes of greater than 50 days gestation, accuracy in pregnant ewes averaged 98% and in non‐pregnant ewes 87%. The Pregmatic 3® was 97% accurate in pregnant ewes after 50 days gestation and was 96% accurate in non‐pregnant ewes. Ewes were examined at between 85 and 185 per hour using these devices. The Medata® external probe was 99% accurate in pregnant ewes of greater than 110 days gestation but less accurate in early gestation. This instrument averaged 89% accuracy in non‐pregnant ewes and an examination rate of 29 to 35 ewes per hour was achieved. The Medata® rectal probe averaged 85% accuracy in pregnant ewes after 70 days gestation. Accuracy averaged 94% in non‐pregnant ewes. Ewes were examined at between 35 and 59 per hour using this device. After 130 days gestation 84% of ewes had firm, obviously enlarged udders and another 14% had slight to moderate udder development. After 130 days gestation thick, clear udder secretions were expressed from 18% of ewes and thick, milky udder secretions were expressed from 8%. Harnessed vasectomised rams raddled one of 118 pregnant ewes (an accuracy in pregnant sheep of 99%) and raddled 53% of non pregnant ewes. It was concluded that the ultrasonic pregnancy testing devices have a commercial role, especially as aids to decision making. Udder scoring may be useful alone or in conjunction with other pregnancy diagnosis methods. Harnessed vasectomised rams are a simple inexpensive method for the diagnosis of pregnancy but they have limited value as expression of oestrus is necessary for optimal results.