Multiple Births in Beef Cows Treated with Equine Gonadotropin (PMS) and Chorionic Gonadotropin (HCG)

Abstract

It is well established that the injection of a wide variety of gonadotropic hormone preparations, including pregnant mare serum (PMS), will result in superovulation. There are many reports of the effectiveness of PMS in inducing superovulation in the cow. However, few studies have been concerned with its effectiveness in inducing superfetation and subsequent multiple births. In general, these studies were not highly successful but did identify many of the associated problems (Hammond and Bhattacharya, 1944; Hammond, 1949; Gordon, Williams and Edwards, 1962; Hafez, Jainudeen and Lindsay, 1965). Promising results were reported by Schilling and Holm (1963) from a limited study involving a sequence of two PMS injections. Their report stimulated the initiation of a study at the Fort Reno Research Station to determine the effectiveness of a sequence of two PMS injections in inducing superovulation and multiple births in beef cows. This study was initiated in May, 1967. It involved 81 lactating beef cows of Angus, Hereford and Angus X Hereford breeding ranging in age from 3 to 8 years. Copyright © 1971. American Society of Animal Science . Copyright 1971 by American Society of Animal Science.