Adaptive dose response pilot study of intravaginal Prostaglandin E2 application in free farrowing sows during parturition
Abstract Background The duration of birth is an important factor influencing the survival of piglets and the health of sows. A prolonged parturition is usually treated with oxytocin, even though several undesirable side effects are described. Therefore, the aim of this study was to evaluate the safety and efficacy of Prostaglandin E2 (PGE2) of different concentrations as an intravaginal applied gel in sows. MethodsTwelve sows were randomly allocated to one of four treatment groups: Group I (control group) application of placebo gel; Group II application of 2.0 mg PGE2; Group III application of 1.0 mg PGE2; Group IV application of 0.5 mg PGE2. The gel was administered intravaginal after the birth of the fourth piglet. Total duration of birth (time between first piglet and last placenta), piglet interval and placenta expulsion duration (time between first and last placenta) were recorded, and each piglet was scored for meconium staining and vitality. Furthermore, stillborn piglets were categorized into ante-partum and intra-partum deaths. Results Although no significant differences between the groups were detected, a beneficial tendency in several parameters was observed in group III. The duration of birth was 284 min (average of 14.3 piglets per litter), whereas in all other groups it was more than 400 min (average of 18.0 piglets per litter). The piglet interval was 10.1 min in group II compared to 10.2 min in group III, 16 min in group IV and 21.4 min in group I. In group III the placenta expulsion duration was 119 min in contrast to the other groups with more than 266 min. Severe meconium staining in more than 10% of piglets was observed in group II and IV. Moreover, piglets of group II showed oedematous and haemorrhagic umbilical cords, lethargy and anoxia, and intra-partum deaths were recorded. Conclusion Although the sample size is limited in this study, it is assumed that an application of 1mg PGE2 intra-partum instead of lower or higher dosages has the most beneficial effects on the birth process in sows and on the vitality of piglets. Further investigation is necessary to confirm the positive effect of PGE2 in daily practise.