Provision of straw and the presence of undocked lambs reduce the behavioural and physiological expressions of pain and stress associated with tail docking in lambs: a preliminary study

Abstract

Aims The aim of this experiment was to determine if the provision of straw and the presence of undocked twins could be used to mitigate the pain experienced by lambs having their tails docked using rubber rings. Methods A total of 54 twin St. Croix 60-days-old weaned lambs were assigned to one of four treatments: (i) the presence of undocked twins and no provision of straw (U); (ii) the provision of straw and no presence of undocked twins (St); (iii) the provision of straw and the presence of undocked twins (StU); and (iv) no provision of straw and no presence of undocked twins (C). Straw was provided as bed material over the concrete floor; whereas the presence of undocked twins was achieved by leaving one twin intact within each pair. From the placement of the rubber rings, the behaviour of tail-docked twins was video recorded continuously for 60 min, and blood samples were taken from these lambs immediately before placing the rubber ring (time 0), and at 0.5, 1, 1.5, 24, 48 and 72 h after, for cortisol and physio-metabolic profiles determination, and at 168 h after, for cortisol determination. Key results Lambs in treatment C spent three times longer in abnormal lying postures (P = 0.002) compared with St and StU lambs (6.49 ± 4.73 vs 1.78 ± 1.26 and 1.83 ± 1.94 min respectively). Lambs in all treatments experienced an increase in cortisol levels 1 h after tail docking, except for StU lambs. In addition, 48 and 72 h after tail docking, lambs in treatments St and StU had lower concentrations of cortisol than C lambs. Conclusion This study shows that the provision of straw and the presence of undocked twins reduce the behavioural and physiological expressions of pain associated with tail docking in lambs. Implications In lambs raised under intensive conditions, the addition of straw as bedding material and the presence of intact tail lambs could be a practical strategy to improve the welfare of tail-docked lambs, whereas for those lambs raised under extensive conditions, leaving intact those lambs that will be sold might serve as social buffering for their tail-docked conspecifics that will remain in the farm.