[Effect of the beta blockader carazolol (Suacron) on parturition in sows].

It was the aim of this study to investigate the effects of the betablocker carazolol (Suacron) on the birth process of the sow. The drug occupies the betareceptors in different organs without causing the stimulation of adrenaline which induces in part the stress reactions of the organism at these receptors. During delivery the stimulation of the betareceptors of the uterus causes a relaxation of the smooth muscles and, hence, prolongs parturition. It could be illustrated that the intravenous injection of the adrenaline-antagonist carazolol (0.5 mg i.e. 1 ml Suacron/50 kg b.w.) increased the contractions of the uterus sub partu in sows. In a double-blind-trial the same dose of the beta-blocker was administered to sows intramuscularly (n = 523). The rate of deliveries lasting six hours or more was reduced (11.0% vs. 14.5%) in the treated group in comparison with the control group (n = 543) that only received a salt solution. Additionally, the beta-blocker prophylaxis led to a reduced stillbirth rate (7.1% vs. 8.3%), caused less necessity for external aid (6.1% vs. 7.8%), decreased the use of oxytocine (28.9% vs. 34.8%) and managed to diminish the occurrence of puerperal disorders (15.5% vs. 19.5%). These beneficial effects on the farrowing are significant at the 5% level and particularly apparent in sows giving birth to the first litter.