Author
SANTURTUN, EDUARDO - University Of Queensland | |
MOREAU, VALERIE - Institute Polytechnique Lasalle Beauvais | |
Marchant, Jeremy | |
PHILLIPS, CLIVE J - University Of Queensland |
Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 1/8/2015 Publication Date: 2/13/2015 Citation: Santurtun, E., Moreau, V., Marchant Forde, J.N., Phillips, C.C. 2015. Physiological and behavioural responses of sheep to simulated sea transport motions. Journal of Animal Science. 93(3):1250-1257. Interpretive Summary: Motion or travel sickness is a potential welfare issue for livestock during transportation. Road transportation has received a relatively large amount of research attention, however transportation by sea has not, even though there are many countries that carry out large scale live export of animals by sea. The objective of the current study was to assess the effects of simulated ship motions on the behavior and cardiac physiology of sheep. Sheep were exposed to the separate ship motions of roll (side to side movement), heave (up and down movement) and pitch (front to back movement) as well as a control treatment of no motion. Heave significantly affected behavior and heart rate measures, with sheep spending more time standing and leaning on support and less time lying and ruminating. Measures of heart rate variability showed that heave reduced the parasympathetic control of heart rate, indicating increased stress. Heave also resulted in the sheep spending more time with their heads in close proximity to each other and seeking companionship. Roll also affected some measures, with sheep showing increased stepping to retain balance and increased heart rates. Pitch did not differ from control. Overall, there was behavioral and physiological evidence that heave and roll caused stress and thus these aspects of motion during sea transportation could result in motion sickness and impacted sheep welfare. Technical Abstract: The motion of ships can cause discomfort and stress in humans, but little is known about the impact on sheep welfare, despite many sheep travelling long distances by ship during live export. We tested whether exposing sheep to roll (side to side movement), heave (up and down movement) and pitch (front to back movement) with similar amplitude and period conditions to a commercial livestock transport vessel would affect their behavior and physiology. Specifically, we tested the effects of these motions, and a control treatment, on behavior, heart rate variability, rumination, body posture and balance of sheep. Four sheep (37 ± 0.1 kg) were restrained in pairs in a crate that was placed on a moveable and programmable platform that generated roll and pitch motions. An electric forklift was used to produce heave motion. The treatments were applied for 30 min each time in a changeover design with one repetition over eight consecutive days. Sheep behavior was recorded continuously from video records and heart rate monitors were attached to determine heart rate and its variability. Heave reduced the time that sheep spent ruminating, compared with the other three treatments (P < 0.001). The two sheep spent more time during heave with their heads one above the head of the other (P < 0.001) and looking towards their companion (P = 0.02), indicating greater affiliative behavior. Sheep spent more time during heave standing with their back supported on the crate (P = 0.006) and less time lying down (P = 0.01). Roll caused more stepping motions than pitch and control, indicating loss of balance (P < 0.001). Heave and roll had increased heart rates and reduced inter-beat intervals, compared to Control (P < 0.001). The inter-beat intervals of sheep in the heave treatment had an increased ratio of low to high frequency duration (P = 0.01), indicating reduced parasympathetic control of stress responses. Therefore there was both behavioral and physiological evidence that heave and roll caused stress, with sheep experiencing roll apparently coping better using regular posture changes and heave causing the sheep to seek close presence to their companion. |