2002 Lebret Ipvs

EFFECT OF A COMBINATION OF VETRABUTINE AND OXYTOCIN ON STILLBIRTH RATE IN SOWS A Lebret1, V Auvigne2 Synthèse Elevage, Pleumeleuc, France, 2Ekipaj, St Gregoire, France

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Introduction and Objectives Incidence of stillbirths is a major cause of piglet loss before weaning. Latest technico-economical french data indicate a mean rate of stillborn piglet of about 8%, which represents half the total losses between birth and weaning. At a national level, the loss of profit reaches hundreds of millions euros. Stillbirth is a multifactorial pathology ; in many cases, neither a nutritional nor an infectious etiology can explain the outbreak of stillborn piglets. In such cases, farrowing management must be analysed ; identification of high-risk sows should especially be required, in order to apply to them an individual and sustained follow-up. Thus, the combination of vetrabutine with oxytocin seems pharmacologically interesting : by regulating and enhancing uterine contractions, one may expect to reduce the farrowing time, hence increasing the number of viable piglets while limiting human interventions. This study aimed at investigating the effects on sows of a systematic injection of vetrabutine hydrochloride associated to oxytocin in the beginning of farrowing. Materials and Methods The study was carried out as a prospective open field study. It was conducted in two farms of the center of France. An overall 152 sows from 14 different batches were enrolled into the study. The animals were divided into two groups. Primipara were equally distributed among the two groups. In the treatment group, each animal systematically received a single intramuscular injection of 4 ml of vetrabutine hydrochloride (MONZAL ND) and one intramuscular injection of 10 IU of oxytocin, since the beginning of farrowing (more often between expulsion of first and second piglet). The control group did not receive any systematic injection. According to the usual protocol of the farmer, in both groups, any sow might be given an oxytocin injection if the time between two consecutive piglet expulsion exceeded 30 minutes. In both groups, the following data were recorded: - data relating to breeding performances (total born piglets (excepted mummified), born alive and stillborn) ; - data relating to farrowing conditions (number of palpations, number of supplementary oxytocin injections, calcium injections, NSAID injections, antibiotic injections) ; - data relating to post-partum pathological events (vaginal discharges, mammary congestion, fever). Results and Discussion The treatment group included 53 sows and 22 gilts and the control group 61 sows and 16 gilts. Farrowing was induced in 86% of the cases. Both groups were comparable with regard to litter rank and parturition induction (Mann-Whitney test, p>0,05). No significant difference was noted between groups

regarding the total number of born piglets and the number of born alive piglets (Tab.1). On the other hand, the mean number of stillborn piglets per litter was significantly reduced in the treatment group (Mann-Whitney test, p<0,05). Table 1. Breeding performances Treatment group Total born 12,8 Born alive 12,0 Stillborn 0,8

Control group 13,2 11,5 1,7

p n.s. n.s. 0,0005

The total number of oxytocin injections performed (excepted systematical injections in the treatment group) was significantly lower in the treatment group compared to the control group (Chi2 test, p<0,01)(Tab.2). Table 2. Additional oxytocin injections* Number of injections 0 1 2 Total Treatment group 65 10 0 75 Control group 45 26 6 77 *p<0,01 No significant diference was found between groups for the other parameters investigated (number of palpations, other injections performed (antibiotic, NSAID, calcium). Fewer post-partum pathological events were observed in the treatment group than in the control group ; however, the difference was not significant given that the size of the sample was not large enough to achieve a sufficient statistical power. Weaning figures would have been interesting ; it can indeed be assumed that loss rate at weaning should be lower if piglets less suffered during farrowing. Vetrabutine regulates uterine contractions and enhances their magnitude (hence the tensing effects of oxytocin are balanced)(1). It was observed in gilts that, in combination with oxytocin, vetrabutine could reduce the meantime between two consecutive piglet expulsion at farrowing (2). This combination seems to improve uterine contractions, making them more efficient ; by reducing the expulsion time, it decreases the foetal suffering and eases the farrowing follow-up. In this study, a systematic administration of a combination of vetrabutine and oxytocin at the beginning of farrowing significantly reduced stillbirth rate. However, the decrease in post-parturm pathological events should be confirmed and the weaning figures be looked at. Références 1. Engelhorn R., Schmidt I. (1956). Arzneim-Forsch. 6 : 454-457. 2. Busch W., Phillip H. and Limper J. (1991). Unpublished report 6821 MON 90-02.