Induced parturition in recipient cattle carrying nuclear transfer calves
Abstract. Historically there has been a lack of spontaneous parturition in nuclear transfer animals produced from somatic cells. A significant number of nuclear transfer calves are born with health problems and died within a week of birth. To a lesser degree in-vitro produced (IVP) calves have had the same abnormalities at birth. There are numerous reports of nuclear transfer calves having placental dysfunction such as hydroallantois or hydroamnion, and placental pathology such as edema or extremely large and/or abnormal placentomes. In an attempt to circumvent some of these maladies, a program was devised to induce recipients carrying nuclear transfer fetuses to calve 1 week earlier than expected full term gestation. All recipient cows were induced toward parturition at day 274 (+/- 2 days) of gestation. The cows were injected IM with 20 mg of dexamethasone (Pro Labs Ltd., St. Joseph, MO, U.S.A.) and 25 mg dinoprost (Pharmacia & Upjohn, Kalamazoo, MI, U.S.A.) 24 hours before an elective caesarian section. Of the 31 nuclear transfer calves born at Trans-Ova Genetics utilizing this procedure, 23 (74%) survived the immediate postnatal period with minimal medical care. Eight calves (26%) died within 36 hours of birth. Placental edema, large birth weights, pulmonary edema and pathological right side heart problems were common findings in the calves that died. Two calves (6%) died later in life from other unrelated health problems. 21 calves (68%) remain for productive ventures. Birth weights on all calves ranged from 38 to 89 kg.