Induction and synchronization of parturition in cattle

Parturition can be synchronized in cattle by inducing or postponing. An intramuscular injection of glucocorticoid and/or Prostaglandin F2a (PGF) induces calving within a few days after the treatment with a high incidence of retention of fetal membrane. A combined administration of a long-acting glucocorticoid and PGF improves the synchrony of partuntion, but does not reduce the incidence of retained placenta. An attempt has been made to reduce the incidence of retention of fetal membrane by using a high dose of estradiol and a long-acting PGF analog without success. Night-time calving can be eliminated by postponing labor overnight with double administrations of such ß2-adrenergic stimulants as isoxuprine, clenbuterol, and ritodrine. The postponement of partuntion shows no adverse effect on cows and newbom calves. It is also possible to synchronize parturition in a narrower time frame by combining the induction and postponement. Further studies are needed to reduce the incidence of retention of fetal membrane following induced calving.