Summary
This project validated the use of Qualitative Behavioural Assessment (QBA) as a measure for assessing the welfare of cattle and sheep under industry-relevant conditions. We tested whether QBA is a reliable, objective and valid measure of the physiological and psychological state of cattle and sheep.
The first, experimental, phase of this research programme examined cattle and sheep during a variety of transport events, using transport as a stressor that could be experimentally manipulated and controlled.
a) Transport studies were conducted on cattle to validate QBA as a measure of welfare state under three potential challenges: animals were compared according to their level of habituation to transport (naive vs. habituated), trailer flooring type (non-grip vs. grip) and driving style (stop-start vs. continuous driving). Observers reached consensus in their use of QBA terms for each transport scenario. Observers distinguished between each of the paired transport treatments in terms of their scores of the behavioural expression of the cattle. Physiological differences were evident between transport treatments (e.g. heart rate, core temperature, hypothalamic-pituitary-adrenal (HPA) axis response and immune function) and QBA scores were correlated with physiological responses in a meaningful way.
b) Sheep were exposed to four common transport challenges: animals were compared according to their level of habituation to transport (naive vs. habituated), trailer flooring type (non-grip vs. grip), driving style (stop-start vs. continuous driving) and degree of ventilation (trailer sides that were closed-in vs. open). Observers reached consensus in their use of QBA terms for each transport scenario. Observers distinguished between each of the paired transport treatments except in the case of the ventilation study (which may reflect that there was only minimal effect of this treatment upon the animal's physiology). Physiological differences were evident between transport treatments (e.g. heart rate, core temperature, HPA axis response and immune function response) and QBA scores were correlated with physiological responses in a meaningful way.
c) An additional experimental study was carried out to validate QBA as a measure of chronic stress. Sheep of different levels of nutritional stress (chronic stressor) were tested for their responses to road transport (acute stressor). There was consensus in the ability of observers to interpret the behavioural expressions of sheep with differing body condition scores (BCS) being road transported at different times of the year and without fasting vs. post-fasting. QBA scores were significantly correlated with physiological variables in a manner that was consistent with the interpretation that the behavioural expression of sheep reflected their physiological state.
From these three experimental studies, it was clear that various road transport scenarios resulted in altered physiological responses. Observers were able to distinguish between treatment groups using QBA and the QBA scores were correlated with physiological responses in a biologically-meaningful way. The second part of this research programme involved working with other researchers to analyse footage of animals collected under various experimental and industry situations to validate QBA as a versatile tool for welfare assessment.
a) In collaboration with other researchers at Murdoch University, we examined QBA of cattle in lairage immediately before slaughter. This study validated QBA against measures of physiology and behaviour collected before (e.g. temperament measured since weaning) and immediately after slaughter. There was consensus between observers in their QBA scores, and correlation between GPA dimensions and physiological and temperament measurements (including slaughter order, tension score at weaning, plasma lactate at the time of slaughter, ultimate pH and plasma glucose).
b) In collaboration with AgResearch NZ, footage of sheep tested in a behavioural demand facility was assessed using QBA. Two experiments were assessed, where lactating sheep were either of
1) differing BCS, or
2) differing rate of BCS decline. In both studies, there was consensus in the observer's assessment of the sheep and observers distinguished between sheep of different BCS treatments.
QBA scores were correlated with quantitative measures of behaviour, illustrating how QBA can add an important interpretative element to quantitative analysis. c) In collaboration with CSIRO Armidale, footage of lactating cattle of differing BCS
1) exposed to an isolation stressor and
2) in a behavioural demand facility were assessed for QBA.
In both studies there was consensus between observers in their assessment of the cattle. However, observers were not able to tell the difference between BCS treatments in either experiment by QBA (matching results of the behavioural demand analysis). Quantitative behavioural assessments of the animals in the isolation stressor study indicated that temperament differences between cattle may have overridden any influence of BCS upon behaviour. QBA scores were correlated with quantitative assessments in the behavioural demand study, again adding an interpretive element to the analysis.
d) In collaboration with researchers from the Beef CRC, footage of cattle chronically exposed to varying levels of fearful (novel) cues were analysed by QBA. The study revealed differences between treatment groups with animals exposed to both chronic and acute exposure to novel stimuli showing different body language from control animals. QBA is a reliable, objective and valid measure of animal welfare.
This research programme has found consensus between observers in their qualitative assessments in all studies and (under most experimental conditions) observers were able to distinguish between treatment groups based on the animal's behavioural expressions. QBA scores are also correlated with key welfare-relevant physiological and behavioural measures. QBA allows whole-animal assessment in an integrative sense. It is a quick and non-invasive assessment that correlates with commonly-used physiological measures of welfare (validated during road transport and in lairage). QBA may therefore be useful as an aid to interpretation of more detailed welfare measures, or to highlight situations that require more intensive welfare assessment, particularly in animal production scenarios where more invasive welfare assessments are difficult to implement.
