The use of oxytocin and carbetocin in farrowing sows and its effect on the duration of parturition

Abstract

Stillbirth in swine production farms remains a major problem despite the use of drugs during parturition and account for 5-8% mortality in normal farrowings (Friend et al., 1962; Randall, 1972a,b; Zaleski and Hacker, 1993; Herpin et al., 1996; Trujillo-Ortega et al., 2007). A short duration of farrowing is important for piglet survival (Randall, 1972b). Pigs have a short survival time when they are exposed to asphyxia; irreversible brain damage occurs within 5 minutes (Miller and Miller, 1965 In: Curtis, 1974; Curtis, 1974). Approximately 82% of the intra-partum deaths occur in piglets born in the last third of the litter (Randall, 1972b). Oxytocin is the most commonly used drug worldwide to accelerate parturition in sows and reduces the expulsion interval between piglets (Muhner et al., 1955 In: Cole and Foxcroft, 1982; Mota-Rojas et al., 2002; Alonso-Spilsbury et al., 2004). There are side effects reported; oxytocin administered intramuscular results in a higher number of ruptured umbilical cords, more intra-partum deaths and more meconium-stained piglets (Mota-Rojas et al., 2002b; Alonso-Spilsbury et al., 2004). Carbetocin is a synthetic octapeptide analogue of the hormone oxytocin (Barth et al., 1975 In: Hunter et al., 1992; Hunter et al., 1992; Engstrøm et al., 1998; Schramme et al., 2008). Carbetocin might be a safe and more effective alternative to oxytocin (Kirkden et al., 2013); accelerates the parturition with possible better fetal outcomes (Hühn et al., 2004; Udluft, 2004 In: Scramme et al., 2008). The purpose of this research was to evaluate the use oxytocin and carbetocin in farrowing sows and its effect on the duration of parturition. This study was performed at two commercial swine farms from November 2012 to January 2013 and the set up was triple blinded. Per farm sows were randomly arranged into three groups of 50 sows; first group received 1 ml (10 IU) oxytocin (Oxytocin®, Dechra) by intramuscular injection in the neck region after the fourth piglet was born, second group received 1 ml (0,07 mg) carbetocin (Longacton®, Dechra) by intramuscular injection in the neck region after expulsion of the fourth piglet, third group received no injection and were only observed. To study the duration of the delivery, total farrowing duration (in minutes) and expulsion interval between piglets (time in minutes between two born piglets) were collected. Also parity, gestation length and litter size of each sow were recorded. In addition other variables of the piglets born were noted, head or breech presentation, aspect of the umbilical cord, sex and weight. In the context of animal welfare according to the Committee on Animal Experiments of Utrecht (DEC), behaviour of the sows was included in this study. Factors affecting the total farrowing duration (TFD), Farrowing Duration after the fourth piglet (FD4+) and four Farrowing Duration (FD) intervals were analysed with a General Linear Model (GLM)procedure; factorial ANOVA. Behaviour of the sows was analysed with a logistic regression. No differences were found between the treatment groups on the behaviour of the sows during the farrowing process; treatment did not affect the welfare of the sows (P>0.05). The amount of intervention was significant in all models; birth assistance prolonged the duration of farrowing compared to sows without birth assistance (P<0.05). There were no differences found between the carbetocin and control group on the duration of farrowing (P>0.05). Treatment with oxytocin was significant compared to the control group; oxytocin prolonged the last part of the farrowing process (interval 4) in sows with litters larger than 12 piglets (P<0.05). A recommendation for farmers is that sows should be regularly monitored during the farrowing process whether they are treated with uterotonic drugs or not; prolonged birth intervals between piglets can be an indicator for farrowing problems.