Date Published: June 13, 2018
Publisher: Public Library of Science
Author(s): Dominique Van der Saag, Sabrina Lomax, Peter Andrew Windsor, Casey Taylor, Peter John White, Francesco Staffieri.
To assess the effects of a topical anaesthetic (TA) and buccal meloxicam (BM) on behaviour, maximum wound temperature and wound morphology following amputation dehorning of beef calves, 50 unweaned Hereford calves were randomly allocated to: (1) sham dehorning / control (CON, n = 14); (2) amputation dehorning (D, n = 12); (3) amputation dehorning with pre-operative buccal meloxicam (DBM, n = 12); and (4) amputation dehorning with post-operative topical anaesthetic (DTA, n = 12). Videos of the calves were captured for 3 h following treatment. Each calf was later observed for 5 min every hour and the frequency and duration of specific behaviours displayed during these focal periods was recorded. Infrared and digital photographs of dehorning wounds were collected from all dehorned calves on days 1, 3 and 7 following treatment. Infrared photographs were used to identify the maximum temperature within the wound area. Digital photographs were used to score wounds based on visual signs of inflammation and healing, using a numerical rating scale of 1 to 3, with morphological aspects of inflammation increasing and morphological aspects of healing decreasing with progressive scores. CON calves displayed fewer head shakes than all dehorned calves at 2 and 3 h following treatment (P = 0.025). CON and DTA calves displayed less head turns than DBM calves at 2 h following treatment (P = 0.036). CON calves displayed fewer combined point behaviours than all dehorned calves at 2 h following treatment (P = 0.037). All dehorning wounds had a greater maximum temperature on days 3 and 7 compared to day 1 (P = 0.003). All wound morphology scores decreased from day 1 to day 3 and wound morphology scores of DBM and DTA calves increased from day 3 to day 7 (P = 0.03). Although flystrike may have confounded these observations, no clear effects of TA or BM on behaviour, maximum wound temperature or wound morphology following dehorning of calves were observed. Further research is required to evaluate the analgesic efficacy of these products for amputation dehorning of calves.
It is well recognised that amputation dehorning of cattle causes pain and distress [1–6]. Despite this, it remains a common procedure as it reduces the risk of injury to cattle and people, damage to infrastructure, space requirements for housing and transport, and the incidence of both hide damage and bruised carcasses at slaughter .
The aim of this study was to evaluate the effects of TA and BM on behaviour, maximum wound temperature and wound morphology, as indicators of pain and inflammation following amputation dehorning of calves. Although these products were investigated as their modes of administration are considered practical for on-farm administration, this study did not demonstrate clear findings of the effects of TA or BM on behaviour, maximum wound temperature or wound morphology when administered alone. No conclusions can be made on the analgesic efficacy of these products for dehorning in calves and further research is required.