Qualitative behavioral assessment of sheep during transport
Wickham, Sarah (2011) Qualitative behavioral assessment of sheep during transport. PhD thesis, Murdoch University.
Animal welfare is a growing concern for society and research into the welfare of animals has increased. Assessment of animal welfare usually includes physiological as well as behavioural measurements; however, these measurements do not give information on the emotional state of the animal. Qualitative behavioural assessment (QBA) has been developed as a method to assess the behavioural expression of an animal and hence the emotional state. QBA has been used to assess the behavioural expression in a number of species; however it had not previously been used in sheep.
The research described in this thesis was conducted to determine whether QBA could be used to assess the welfare of sheep during a stressful event. Transport, as a known stressor, is a key component of sheep farming in Western Australia, with sheep transported from farm to abattoir as well as to feedlots and shipping ports. Therefore, transport was chosen as the stressor. Continuous video footage recorded during each trip was used to provide unidentified clips of individual animals that were shown to observers for QBA.
Fourteen Merino wethers were assessed during their first road trip (naïve transport), and then again on their seventh trip, 8 days later (habituated transport). They were then assessed during transport with altered flooring (slip vs. non-slip), ventilation (open vs. closed) and driving conditions (stop-start vs. continuous). Blood samples were collected immediately before loading and after unloading, and heart rate and core body temperature were measured continuously throughout each trip.
There was significant consensus amongst observers in terms of their assessment of the behavioural expression of the sheep. Observers were able to distinguish between transport-naïve and transport-habituated sheep, between sheep transported with differing flooring conditions and driving conditions. However, observers were not able to distinguish between sheep transported with different ventilation. The physiological response to transport varied depending on the type of transport stressor imposed, but there were significant correlations between the physiology and the behavioural interpretations (QBA scores) in all experiments.
Further studies were conducted to determine the effects of nutritional status on the behavioural responses to a stressful event; transport. Sheep undergoing transport often have different nutritional backgrounds and in addition to this they are usually kept off feed and water for a period of time before transport. It is also known that the nutritional demands on sheep changes with time of year and feed availability. Therefore it was investigated whether QBA could be used to determine if sheep with different nutritional backgrounds, at different times of the year, exhibited different behavioural expressions during transport. In addition, the effect of feed and water withdrawal for 36 hours before transport was investigated.
Observers were able to distinguish between sheep transported in July (increasing day length) compared to January (decreasing day length) and between high and low BCS sheep. Observers did not detect significant differences in the behavioural expression of sheep with increasing and decreasing BCS transported at different times of the year. Observers were able to distinguish between sheep of BCS 1.5 and decreasing BCS, and between sheep of BCS 3.5 and increasing BCS transported pre- and post-fast; however, observers did not detect significant differences in the behavioural expression of sheep with BCS 1.5 and BCS 3.5 transport pre- and post-fast. The physiological responses to transport varied depending on nutritional status, but there were significant correlations between the physiology and the behavioural interpretations (QBA scores).
Behavioural assessments are open to observer bias, and information on the background of the observers (such as sex, age, country of birth, area of study/employment, habitat, dietary preference, purchasing habit, pet ownership, level of experience with sheep, and occurrence of seeing sheep transported) as well as their opinions on sheep and animal welfare and behaviour were collected during the study and it was investigated whether these factors had an influence on how the observers perceived behavioural expression. There were some effects of observer background, with Australians, vegetarians, and observers with low levels of experience with sheep perceiving one dimension of behavioural expression more than other observers. However, all of the observers were still able to reach consensus in their interpretation of the behavioural expression of the sheep. In conclusion, these data suggest that people from the divergent backgrounds assessed in this study achieve a high degree of interpretational agreement when assessing behavioural expression in transported sheep.
A final experiment investigated the correlation between temperament and behavioural expression of the sheep. There is variability between individual animals in their behavioural response to an environment and this variability in response is interpreted as the temperament of the animal. Observers assessed the behavioural expression of sheep under different nutritional states (low: BCS 1.5; high: BCS 3.5) and these results were correlated with temperament measures taken of the sheep. Observers saw no difference between the nutritional groups in their behavioural expression and there was also no difference in the temperament between the nutritional groups.
This work has led to a greater understanding of the behavioural expression of sheep during transport and the ability of observers to assess that behavioural expression. Observers reach consensus in their interpretation of behavioural expression, and QBA scores correlated with physiological measures in an informative way. QBA successfully detected different behavioural responses to transport in sheep and it is suggested that QBA can be used as a practical and informative measure of behavioural responses in sheep and to transport. This research has set a foundation for further study of the qualitative behavioural assessment of sheep in a number of experimental and on-farm conditions.
|Publication Type:||Thesis (PhD)|
|Murdoch Affiliation:||School of Veterinary and Biomedical Sciences|
|Supervisor:||Collins, Teresa, Fleming, Trish, Miller, David, Barnes, Anne and Beatty, David|
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