Behavioural and neuroendocrine responses in alpacas (Vicugna pacos) to the shearing procedure

Abstract

Shearing is a necessary procedure which can cause stress in alpacas. Reactions to stressful situations can include behavioural and physiological changes in an animal's effort to maintain homeostasis. There has been limited investigation on stress mechanisms in terms of behaviour and physiological changes in alpacas, with a focus on heart rate and cortisol in faeces and saliva. This study aimed to determine alpaca behaviour and the concentrations of selected neuroendocrine indicators (cortisol, dopamine, noradrenaline, serotonin, thyroxine) at: pre-shearing (3 days before shearing), on the day of shearing and post-shearing (5 and 10 days after shearing). This study examined 20 alpacas. Compared with the behaviour observed before shearing, shearing performed by the standing method caused only an acute behavioural stress response on the day of shearing and no change 5 and 10 days after shearing. Higher stress activity during shearing was not strongly correlated with the intensity of their everyday reactions to the environment. In contrast, noradrenaline increased and thyroxine decreased after the shearing procedure, changes indicative of mid-term stress symptoms. There were significant correlations between some behavioural and neuroendocrine indicators, confirming the involvement of cortisol, serotonin and noradrenaline in the mechanisms of alpaca behavioural regulation.