Impact of shearing sheep on feeding and behaviour during the pre-embarkment feedlot phase of live export

Abstract

Context Shearing is a management procedure that can induce stress, and is one that sheep often undergo on-farm and/or at registered premises during the pre-embarkation phase of live export. Aim As inanition is one of the largest causes of death during sea transport and can result from sheep experiencing stress, whether shearing results in behavioural changes and stress before boarding a vessel needs to be determined. Methods A total of 600 merino wethers sourced from one farm were housed at registered pre-embarkment premises, where they were split between two adjacent pens. The wethers were further split into the six treatment groups (unshorn, and sheep shorn on Days 1, 2, 3, 4 or 5) with 50 sheep per treatment, per pen. All wethers were fitted with radio frequency identification tags that were used to record animal presence at feed and water troughs, and coloured ear tags to visually identify their treatment group. Temperature and humidity sensors were placed on the outside of each pen to record environmental conditions throughout the 13-day study. Body condition scores for each wether were recorded at the beginning and end of the study. Four portable cameras were placed at a corner of each pen, allowing behaviour states (standing, lying or locomotion) of the wethers to be recorded on Days 1, 2, 3, 4, 5 and 13 of the study. Key results Shorn treatment groups were observed to spend more time standing (F5,5 = 6.63, P = 0.029) and less time lying (F23,23 = 2.48, P = 0.017). The control group spent more time at water troughs from Day 4 to 12 (F5,55 = 3.98, P < 0.01), whereas all groups were recorded as spending more time at the feed trough on Day 5 (F5,55 = 2.78, P < 0.001). Conclusions A lack of variation in behavioural states between the treatments and no change in time spent feeding throughout the study suggest that the procedure of shearing within the first 5 days at the pre-embarkation facility had no impact on behaviour of these sheep. Implications These results assist the industry in ensuring best management practices are implemented.