Lambing is an important period in the calendar of events for sheep producers, and its success greatly contributes to the financial outcome of sheep enterprises. On-animal technologies utilizing accelerometers to track behaviour could be useful in supporting shepherds during this period for the recognition of parturition events. Using accelerometers fitted to the leg, the aims of this study were to determine whether biological and physical measures of periparturient sheep are associated with their behaviour and whether there are quantifiable changes in the behaviour of housed sheep relative to parturition. Accelerometer data were collected from 77 (36 single-bearing and 41 twin-bearing ewes), housed, Welsh Mule sheep during the 2019 lambing season on a commercial lowland farm. Accelerometer data for the final 48 h relative to parturition for each ewe were processed hourly to determine the response variables total lying time, mean lying bout duration and total lying bouts. Response variables were modelled as a function of ewe age, lamb sex, ewe BCS, lambing difficulty score, lamb birth weight, the number of sheep in the pen when each ewe gave birth, the period when each ewe gave birth and the hour relative to the hour of lambing using hierarchical generalized additive models. Of the five candidate models evaluated, the model that best fitted each response variable was that which assumed a common behaviour pattern across the final 48 h but also allowed for ewe-specific deviations in behaviour. Ewe BCS, the period of lambing and time relative to the hour of lambing were significantly associated with total lying time. Only time relative to the hour of lambing was significantly associated with mean lying bout duration and total lying bouts. We also found a significant reduction in both hourly lying time and mean lying bout duration beginning 8 h before parturition and a significant increase in hourly lying bouts from 4 h before parturition. This is the first study to document that both ewe BCS and the period of lambing were associated with ewe behaviour before parturition and highlighted the utility of accelerometers in identifying changes in behaviour relative to parturition. This study could inform the development of alert algorithms for shepherds in the management of impending lambing. However, it should be recognised that some sheep may deviate from a common behaviour pattern which is an important consideration in the prediction of parturition. • Ewe body condition score and the time of lambing affect the lying behaviour of housed, pregnant sheep. • Accelerometers capture changes in lying behaviour of housed sheep relative to parturition. • Simple algorithms based around measures of lying could be developed to generate alerts for shepherds.
Williams et al. (Fri,) studied this question.