INDUCTION OF PARTURITION IN CATTLE - EFFECT OF TRIAMCINOLONE PRETREATMENT ON THE INCIDENCE OF RETAINED PLACENTA

Two experiments were designed to determine whether pretreatment with t riamcinolone acetonide (TRI) prior to induction of parturition with de xamethasone (DEX) and cloprostenol (CLO) would reduce the incidence of retained placenta. Experiment 1 was conducted to determine the optimu m dosage of TRI and to approximate the optimum interval from TRI to in duction with DEX+CLO. All cows received TRI on day 270 of gestation. C ows in group I received 1 mg/30 kg of body weight (BW) of TRI and were induced to calve with DEX+CLO on day 276. Cows in groups II and III r eceived 1 mg/45 kg BW and were induced on days 276 or 277, respectivel y. Cows in groups IV and V received 1 mg/60 kg BW and were induced on days 277 or 278, respectively. Group VI cows served as untreated contr ols. There was no difference in the incidence of retained placenta amo ng the treated and control groups. Experiment 2 was conducted to more precisely determine the optimum interval from pretreatment to inductio n treatment with the chosen dose of TRI. All cows in group I, II, and III were pretreated with 1 mg/60 kg BW of TRI on day 270 of gestation and received DEX+CLO on days 275, 276 or 277, respectively. Group IV c ows served as untreated controls. The incidence of retained placenta w as higher (p < 0.05) in groups I and II than in the control group, wit h group III intermediate and not different from the others. Cows that retained their placentas had higher (p < 0.05) body temperatures from day 2 to day 7 after calving and tended to have a lower pregnancy rate in the subsequent breeding season than cows that did not retain their placentas. Results indicate that pretreatment with TRI seven days pri or to induction of parturition with DEX+CLO resulted in a reduced inci dence of retained plancenta, apparently by advancing placental maturat ion.