Effects of meloxicam and flunixin on pain, stress and discomfort in male piglets during and after surgical castration

Surgical castration of young male piglets is now a generally accepted cause of serious distress and impairment of animal welfare. Awareness of this problem has created the moral commitment to seek for practical and more humane alternatives. As one possible alternative, the application of analgesics has been installed in Germany as an interim solution by the QS system, thus mandatory for the majority of German pig producers.Two analgesics have been authorised for this purpose. Both have been shown a significant positive impact on cortisol levels if administered pre-operatively. However, their effects on pain, stress and discomfort during castration, and on the post-castration period are conflicting. Thus, the aim of the present study was to compare the effects of Meloxicam and Flunixin on cortisol levels, behavioural indices, vocalisation, and wound healing of surgical castrated piglets in the field. There was no difference in vocalisation during castration in analgesic treated and untreated piglets. Piglets castrated under analgesia still had significantly elevated serum cortisol levels 30 min post castration, when compared to the sham castrated group. Both analgesics led to a significant impairment of behavioural indices and wound healing. It is concluded that analgesics can improve the welfare of piglets during the first part of the post-castration period. However, the benefits may be considered small and may not meet the requirements of the EU. Hence it is of high importance to prevent the interim practice of surgical castration of male piglets under analgesics from becoming implemented as a permanent condition in pig production.