Using Pen-Side Measurable Blood Parameters to Predict or Identify Dystocic Lambing Events

Dystocia is the greatest contributor to neonatal lamb mortality in Australia and poses significant welfare and economic concerns worldwide. In this study, we set out to investigate whether pen-side analysis technology could be employed to detect blood parameters predictive of dystocic labour events in sheep. In a pilot trial, we collected and analysed blood samples in pen-side assays for glucose, lactate, pH, pCO2, pO2, base excess, HCO3, TCO2, sO2, lactate, sodium, potassium, chloride, calcium, urea nitrogen, creatinine, haematocrit, haemoglobin and anion gap. From the pilot data, we identified creatinine, TCO2, chloride and calcium as potentially useful markers. To develop a time course and to establish variability of the selected blood parameters, a time series of samples was collected from 12 ewes, from mid-gestation to 48 h after birth. For the main trial, blood samples were collected at mid- and late gestation for glucose determination and for the full set of blood parameters at three time points before, at and after birth. Possible predictors of lambing difficulty were chloride, haematocrit and haemoglobin, sampled one week before birth; creatinine, sampled at birth; and blood pH and base excess after birth. In conclusion, we found that pen-side analysis of blood markers showed promise in identifying dystocic lambing events

Lamb survival, a challenge for the decades

Lamb survival to weaning is the major profit driver in the Australian sheep industry, and equally an important issue for animal welfare and ethical livestock production. Research aimed at improving lamb survival and reproductive efficiency remains consistently one of the highest- ranking priorities identified by industry consultation groups. The extensive body of knowledge generated by research efforts across Australia have led to comprehensive management guidelines and extension programs to support their uptake. Nevertheless, reported rates of loss in many regions remains higher than acceptable, despite lamb loss rates in general improving under improved management strategies. One of the biggest challenges is to break down this complex phenotype into measurable meaningful component traits. As for any complex phenotype, a combination of improved management and genetic selection may be most likely to lead to success but for either application, phenotypes must be less dependent on uncontrollable environmental influences than counts of losses. Dystocia has been conclusively shown to be one of the most important causes of lamb loss and development of approaches to measure incidence of dystocia will aid the development of new phenotypes to facilitate genetic and management strategies to improve lamb survival

Using Pen-Side Measurable Blood Parameters to Predict or Identify Dystocic Lambing Events

Dystocia is the greatest contributor to neonatal lamb mortality in Australia and poses significant welfare and economic concerns worldwide. In this study, we set out to investigate whether pen-side analysis technology could be employed to detect blood parameters predictive of dystocic labour events in sheep. In a pilot trial, we collected and analysed blood samples in pen-side assays for glucose, lactate, pH, pCO2, pO2, base excess, HCO3, TCO2, sO2, lactate, sodium, potassium, chloride, calcium, urea nitrogen, creatinine, haematocrit, haemoglobin and anion gap. From the pilot data, we identified creatinine, TCO2, chloride and calcium as potentially useful markers. To develop a time course and to establish variability of the selected blood parameters, a time series of samples was collected from 12 ewes, from mid-gestation to 48 h after birth. For the main trial, blood samples were collected at mid- and late gestation for glucose determination and for the full set of blood parameters at three time points before, at and after birth. Possible predictors of lambing difficulty were chloride, haematocrit and haemoglobin, sampled one week before birth; creatinine, sampled at birth; and blood pH and base excess after birth. In conclusion, we found that pen-side analysis of blood markers showed promise in identifying dystocic lambing events

Physiological and Behavioural Patterns Associated with Prolonged Lambing Events in Sheep

Dystocia is one of the most important issues faced by sheep producers nationally and internationally. In Australia specifically, dystocia directly and indirectly accounts for 50-75% of all neonatal lamb mortalities. Similar figures have been reported in flocks in New Zealand and the UK. Dystocia has been the subject of research for decades" however, the outcome studied is almost always 'number of lambs dead', therefore excluding dystocic events that did not result in death. This thesis is comprised of a series of experimental manuscripts investigating dystocia and its effect on maternal behaviour pre- and post-birth" assessing on-animal accelerometers to identify differences in eutocic and dystocic ewe activity pre-birth" and using pen-side blood analysis techniques to identify maternal blood markers that may be indicative of a dystocic event before and after birth. Dystocia has a marked effect on the behaviour of the ewe in the hours before birth. Dystocic ewes are significantly more active overall – identified by accelerometer data alongside traditional observation and annotation methods – but reach the peak in their activity 3 h before birth, whereas eutocic ewes reach the peak in activity at birth. There is also a significant difference in ewe behaviour after birth, with dystocic ewes performing fewer maternal care behaviours and more avoidance behaviours. Finally, there are multiple blood markers seen to be different in eutocic and dystocic ewes before and immediately after birth" however they are cohort-dependent.Dystocia is a complex and multifaceted problem, and requires a multifaceted approach in order to appropriately address the underlying issues and develop practical detection and prevention strategies

Postnatal maternal behaviour expression depends on lambing difficulty in Merino ewes

Dystocia, a prolonged or non-progressive birth event, is the main contributor to lamb mortality in Australia and across the world. Dystocia can cause neonatal hypoxia, central nervous system (CNS) damage leading to increased risk of starvation, exposure and mismothering, and death. These prolonged birth events can also cause fatigue, injury and death in the ewe. Dystocia may interrupt the expression of maternal behaviour and the strength of the ewe-lamb bond, and consequently lamb survival. This study focused on the effect of dystocia on ewe behaviour in the 2 h post-lambing. A total of 18 ewes were chosen for continuous behaviour annotation and analysis (dystocic (n = 9) and eutocic (n = 9)) based on the quality of video recordings, length of stage 2 parturition and classification by a single experienced observer. Dystocic ewes showed significantly lower expression of maternal behaviours and a significantly greater expression of avoidance behaviours compared to eutocic ewes. Additionally, dystocic ewes performed fewer behaviours in total compared to eutocic ewes

Physiological and behavioural patterns associated with prolonged lambing events in sheep - Dataset

This data was created in the process of researching the thesis Physiological and behavioural patterns associated with prolonged lambing events in sheep. The data was collected between march 2018 and november 2019 at CSIRO Armidale. The data includes behavioural data (video records and behaviour annotations), blood samples (lab and pen-side analysis), general lambing husbandry procedures and observations and accelerometery