Title of Research

An analysis of Peri-Parturient and Postnatal Events in Thoroughbreds.

Abstract

Parturition in the mare is a rapid event in three stages, where each stage can be an indication of health and wellbeing of mare and foal. It is essential to be able to assess potential abnormalities in any of the stages of the parturition. Additionally, the neonate displays essential behaviour patterns after birth in the extra uterine environment that may have an effect on its further development. Although there are previous descriptions of parturition and neonatal behaviour, many of these studies either employed small sample sizes or alternatively only looked at one or two aspects of this event. Similarly assessment of peri-parturient and postnatal behaviours has often been carried out in separate studies, with varying sample size. This study set out to analyze and clarify some aspects of equine parturition and potential factors affecting these. Data on a sample set of 1,297 parturitions was obtained from foaling reports of a large Irish stud farm (1993 – 2006). The variables that were subsequently used in the study included covering date of the mare, foaling date of the mare, mare parity, mare age, time of rupture of the chorioallantoic membrane, occurrence of dystocia, time when the foal was on the ground, time when the foal stood unassisted, time when the foal nursed the mare successfully, time when the enema was given, time of meconium passage, time of placental expulsion,. Incidence of premature placental expulsion, incidence of premature placental separation, foal weight and foal sex. For 1,294 parturitions that mean gestation length was 340.370.27 days. Gestation length was significantly affected by season/photoperiod, foal sex, foal weight (p<0.001) and mare parity (p<0.05). The majority (83%) of parturitions took place between 19:00 and 7:00 o’clock. The mean duration of second stage labour was 17.510.30 minutes. The mean interval from birth of the foal to standing successfully was 47.980.55 minutes and the mean duration from birth to the foal nursing was 92.450.88 minutes. Additionally the birth to standing interval was significantly affected by sex, parity and foaling difficulty (p<0.05) and the duration to nursing was significantly affected by both parity and sex (p<0.05). The incidence of dystocia in 1,297 mares was 17.1%. Premature placental separation occurred in 6.3% of all years combined and 12.9% in 2006. The study provides important baseline data on peri-parturient events and neonatal behaviours in the thoroughbred mare and foal. Since the previous most recent study of similar sample size was conducted in 1975, the findings should be of use in defining the normal parameters of foaling in the thoroughbred industry.

Author

Morscher, Soraya

Year

2007

Establishment

University of Limerick

Level

Bachelor