Two experiments were conducted to investigate the physiological responses of Bos taurus (Angus cross, n = 6) and Bos indicus (Brahman, n = 6) cattle to prolonged heat and humidity, as can occur during live export by sea. Each experiment was carried out in climate-controlled rooms, where heifers were exposed to 15 d of sustained heat and humidity. The treatment was designed to be representative of a long-haul, live-export voyage leaving a southern Australian winter and traveling to a Middle Eastern summer. Wet bulb temperature (WBT) was used to give a combined measure of dry bulb temperature and relative humidity and was increased over several days, culminating in 5 d at 32°C WBT between d 7 and 11. By d 11, the respiratory rate and core body temperature increased (P < 0.001) compared with values at lower ambient temperature on d 1 and 2 when climate-controlled rooms were not operating. Feed intake of Bos taurus was reduced (P < 0.001) by d 11, whereas that of Bos indicus did not change (P = 0.14). Despite no diurnal variation in climatic conditions, core body temperature of both Bos taurus and Bos indicus continued to show a circadian amplitude of approximately 1°C throughout the hottest period. This amplitude increased during the recovery period after heat was removed (up to 1.8°C for Bos indicus and 1.6°C for Bos taurus). Water intake for both Bos taurus and Bos indicus increased when WBT increased (P < 0.01 on d 11). Significant acid-base and blood electrolyte imbalances occurred in both Bos taurus and Bos indicus, with changes in Bos taurus being more substantial and prolonged. The increase in respiratory rate coincided with a decrease in the partial pressures of carbon dioxide and bicarbonate in venous blood. However, during the hottest period, average daily venous blood pH remained unchanged. When the heat load was reduced after d 11, the blood pH decreased, indicating metabolic acidosis. Blood pH declined from 7.44 to 7.36 for Bos taurus (P < 0.001) and from 7.44 to 7.38 for Bos indicus (P < 0.001). Other parameters measured include heart rate; packed cell volume; plasma and urine Na, K, and Cl; urine pH; and specific gravity. Our results suggest that Bos taurus cattle experience significant physiological changes during exposure to prolonged and continuous high heat and humidity, with alterations persisting for some days after the heat-stress conditions subside. Bos indicus experience similar but less pronounced physiological changes.

The present study examined whether observers could distinguish between cattle that are naïve to road transport and the same cattle after becoming more habituated to transport. The behavioural expression of cattle was assessed through the method of qualitative behavioural assessment (QBA), and these assessments were correlated with various physiological parameters. Fourteen Angus steers were assessed during their first road trip and then again on their ninth trip, 15 days later. Blood samples were collected immediately before and after transport, and heart rate and core body temperature were measured continuously throughout each trip. Video footage recorded during each trip was edited and clips showing each individual within the first 30 min of departure were randomly ordered and shown to observers for QBA. There was significant (P < 0.001) consensus among 40 observers in their assessment of behavioural expression of the cattle. Transport-naïve cattle were described as more ‘agitated’, while transport-habituated were described as more ‘calm’. Core body temperature (P < 0.01), plasma glucose (P < 0.05) and the neutrophil : lymphocyte ratio (P < 0.01) were higher for the first trip than for the habituated trip (P < 0.01). QBA were significantly correlated with core body temperature (P < 0.01), heart rate (P < 0.01), plasma glucose (P < 0.05) and the neutrophil : lymphocyte ratio (P < 0.01). QBA appears to be a valid and integrative method of assessing cattle welfare under the conditions tested within the present study. There was significant consensus in the ability of human observers to interpret behavioural expression of cattle during this experiment. In addition, observers could identify differences in behavioural expression between cattle that were naïve versus habituated to transport, and these differences were supported by physiological measurements.

Animal welfare is increasingly important for the Australian livestock industries, to maintain social licence to practice as well as ensuring market share overseas. Improvement of animal welfare in the livestock industries requires several important key steps. Paramount among these, objective measures are needed for welfare assessment that will enable comparison and contrast of welfare implications of husbandry procedures or housing options. Such measures need to be versatile (can be applied under a wide range of on- and off-farm situations), relevant (reveal aspects of the animal’s affective or physiological state that is relevant to their welfare), reliable (can be repeated with confidence in the results), relatively economic to apply, and they need to have broad acceptance by all stakeholders. Qualitative Behavioural Assessment (QBA) is an integrated measure that characterises behaviour as a dynamic, expressive body language. QBA is a versatile tool requiring little specialist equipment suiting application to in situ assessments that enables comparative, hypothesis-driven evaluation of various industry-relevant practices. QBA is being increasingly used as part of animal welfare assessments in Europe, and although most other welfare assessment methods record ‘problems’ (e.g. lameness, injury scores, and so on), QBA can capture positive aspects of animal welfare (e.g. positively engaged with their environment, playfulness). In this viewpoint, we review the outcomes of recent QBA studies and discuss the potential application of QBA, in combination with other methods, as a welfare assessment tool for the Australian livestock industries.

Objective and issue-neutral qualitative assessments of livestock behavior could provide a powerful assessment of welfare, augmenting quantitative measures such as autonomic and endocrine changes, which are often difficult to assess under many commercial livestock conditions. We set out to validate the use of qualitative behavioral assessment (QBA) in sheep using controlled experimental conditions (transport as a challenge) and comparing assessments against physiological variables. The behavioral expression of 14 Merino wethers, which had never experienced land transport, were assessed during their first road event (naïve to transport), and then again on their seventh event, 8 d later (habituated to transport). Blood samples were collected immediately before loading and after unloading, and heart rate and core body temperature were measured continuously throughout each event. Continuous video footage recorded during each event was used to provide clips of individual animals that were shown to observers for QBA. There was significant consensus (P < 0.001) amongst 63 observers in terms of their assessment of the behavioral expression of the sheep. Transport-naïve sheep were assessed as being more ‘alert’, ‘anxious’, and ‘aware’, whereas transport-habituated sheep were more ‘comfortable’, ‘tired’, and ‘confident’ (P = 0.015). Heart rate and heart rate variability, core body temperature and a stress leukogram were greater (P < 0.05) in sheep during the first (naïve) event compared with the habituated event, and were significantly correlated with the QBA scores (P < 0.05). In conclusion, QBA is a valid, practical and informative measure of behavioral responses to transport. Copyright © 2012. American Society of Animal Science .