Behavioural effects of a thoracic squeeze on healthy neonatal mammals of precocial species : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Physiology at Massey University, Manawatū, New Zealand

Some neonatal farm mammals that are apparently healthy do not behave normally after birth and without intervention, often die. Recently, a thoracic squeeze has been applied to these neonates, which observed their entrance into a ‘non-responsive state’, from which they rapidly recover when the squeeze is released to express normal healthy behaviours. In addition, healthy newborn foals also become non-responsive during application of the thoracic squeeze. To date, there have been no systematic studies into the effects of the thoracic squeeze on healthy neonates of other precocial mammalian species. This preliminary research aimed to describe the responses of healthy newborn piglets and calves to a standardised application of the thoracic squeeze, and evaluate the effectiveness of the method of squeeze application in eliciting a non-responsive state. Neonatal piglets and calves were squeezed around the chest with either a soft fabric rope or a modified inflation cuff. Physiological parameters were monitored for abnormal changes, while induction behaviour and neural reflex activity were measured. Behavioural data indicated that the thoracic squeeze was effective at eliciting a non-responsive state in all piglets in the study and maintaining this state in half of all the piglets induced, with reduced or absent reflexes in nearly all piglets. In contrast, 81% of the calves were induced into a lower-responsive state, with half of all calves squeezed maintaining this state for the full observation period and present reflexes observed for nearly all calves. Furthermore, the cuff appeared to be more effective at inducing both piglets and calves into a non-responsive or lower-responsive state than the rope, with a faster application and removal. These findings suggest that the non-responsive state reported in foals can be generalised to neonates of other precocial species. The thoracic squeeze has been demonstrated to be inherently safe and effective at inducing and maintaining a non-responsive state in neonates. This pilot study provides a foundation for further research using the inflation cuff to explore the mechanisms underlying the thoracic squeeze and ways in which the squeeze can be effectively applied in an industry context