Early Pregnancy Diagnosis in the Bovine

Abstract

A method of pregnancy diagnosis in the bovine, using crystallization patterns of cervical mucus and contraction of the vagina in response to oxytocin, is described. Long, fern-like crystals form during estrus but not at other periods of the cycle. The vagina contracts in response to oxytocin, either at estrus or during pregnancy. By combining a crystallization pattern other than the very marked pattern at estrus and a positive vaginal contraction under the influence of oxytocin, pregnancy was diagnosed. Eighty-five per cent of 33 cows was correctly diagnosed at 15 days post-breeding. Errors on three cows may be justified by their elongated cycles and possible embryonic mortality. All pregnant cows were diagnosed correctly. Ninety per cent of 21 cows was diagnosed correctly at 27 days post-breeding. © 1967, American Dairy Science Association. All rights reserved.