The Welfare of Sheep: Review of Recent Literature

or Summary of Interesting Publications Boivin,X., Nowak,R., Le Neindre,P., Tournadre,H. , Le Neindre,P. 1997. Discrimination between shepherds by lambs reared under artificial conditions. Journal of Animal Science 75:2892-2898. Few experiments have demonstrated that the identity of a stockman can play a role in the reaction of farm ungulates toward a human. In this study, the researchers looked at the ability of 32 lambs reared artificially in groups of four to discriminate between their shepherd and an unknown shepherd. Half of the lambs were bottle fed in isolation by one shepherd during the first 3 weeks while the other half was fed alternately by three shepherds. The lambs were then tested at 3, 6 and 14 weeks of age to find out the effect of rearing conditions on the response to isolation and to reunion with the known or an unknown shepherd. Some of the behaviours measured were the number of vocalizations, number of squares crossed, latency to interact with the shepherd, and time spent interacting with the shepherd. During the test performed at 3 weeks, lambs interacted more quickly, interacted longer and vocalized less with the known shepherd than with the unknown shepherd. These behaviours were noted more at 3 and 6 weeks than at 14 weeks. These results showed that lambs can distinguish among different people and that fear responses to isolation are reduced more when a known shepherd is present. Also, this ability to discriminate among handlers was most apparent at week 3 and 6 and by week 14 had disappeared. Therefore, knowledge of the shepherd in early age can greatly affect a lamb's reactions to that shepherd and this could help the usual shepherd handle the lambs and ease the fear and stress in the lambs. Graham,M.J., Kent,J.E., Molony,V. 1997. Effects of four analgesic treatments on the behavioural and cortisol responses of 3-week-old lambs to tail docking. The Veterinary Journal 153:87-97. Tail docking is regularly practiced to reduce the risk of blowfly strike. However, there is concern over the welfare of the animals undergoing this procedure as many studies have indicated that all commonly used methods result in signs of acute distress. In this study, the behavioural and cortisol responses of lambs were used to determine which of three methods of tail docking (rubber ring, Burdizzo and rubber ring combined, or heated docking iron) produced the least signs of pain in the first 3 hours after use and which of four anaesthetics (1.0 ml bupivacaine subcutaneously, 0.5 ml bupivacaine epidurally, a topical cold analgesic spray or diclofenac 1.5 mg kg) was most effective in reducing these signs. It was found that compared with the rubber ring alone, the application of the Burdizzo crush as well as the ring reduced the incidence of active behaviours, the cortisol response and the time spent in abnormal positions. Docking with a heated cautery iron produced the least changes in behaviour and cortisol levels, but that does not mean that this method is the best as it can produce lesions that can lead to chronic infections. Subcutaneous injection of the local anaesthetic at the ring site just before application of the ring was the most effective means of reducing the pain from this method. From these findings, it was concluded that if a practical means can be found to produce a local anaesthetic quickly and without the use of needles, then the method of ring tail docking could be more humane. Kent,J.E., Molony,V., Graham,M.J. 1998. Comparison of methods for the reduction of acute pain produced by rubber ring castration or tail docking of week-old lambs. The Veterinary Journal 155:39-51. The rubber ring method for castration and tail docking of lambs is widely used, but has been shown to produce considerable acute pain in all ages of lambs up to six weeks. In this study, a bloodless castrator was compared with an injection of local anaesthetic in their ability to reduce pain for rubber ring castration. As well, the effectiveness of a needleless injection technique was compared with a conventional injection. The results showed that for castration, the most effective method in reducing pain was the application of the ring, followed by an injection of local anaesthetic and then by the application of the bloodless castrator. For rubber ring tail docking, the most effective method was a needleless injection of local anaesthetic without the use of the bloodless castrator. Injections of local anaesthetic by either the needle or the needleless injector were effective, but the needleless injection was safer, quicker and easier to apply. From the results, it was concluded that the injection of a local anaesthetic immediately after the application of the rubber ring effectively reduced, but did not completely eliminate, the acute pain produced by this method of castration and tail docking. Knowles,T.G. 1998. A review of the road transport of slaughter sheep. Veterinary Record 143:212-219. This paper reviews the past and recent scientific literature relevant to the road transport of slaughter sheep. Recommendations for the best practices are given and areas that require further work are also identified. When conditions are difficult, individual animals use various methods to try to counteract any adverse effects of those conditions. This may involve changes in behaviour and shifts in physiological variables away from values that are typically considered to be "normal". There are many types of measurements that can be used to assess the effects of transport. They are mortality, injury and disease, immune function, meat quality, weight loss, the levels of muscle and liver glycogen, plasma free fatty acids, urea, and B-hydroxybutyrate, and blood measurements of total protein, albumin, packed cell volume and osmolality. The death or injury of an animal is an extreme but useful measurement of welfare. However, mortality rates and levels of injuries among lambs are low when compared with those of other farmed species and considering the numbers of animals transported. Before being loaded onto a truck, sheep can show signs of stress due to previous handling. Loading and the initial few hours of transport cause a sharp increase in heart rate, muscle activity and plasma hormone concentrations, but these factors decrease after 9 hours. Transport can involve long periods without food or water. One result is a loss of liverweight and a reduced carcass weight. During long journeys, a mid-transport lairage stop for food, water and rest should provide a chance for recovery from the effects of the journey before it is resumed. However, short rest periods do not seem to be of real benefit and could even be detrimental. There is little experimental work on which to base stocking densities, but evidence does suggest that animals require space in which to make positional adjustments in order to maintain their balance. The author concluded that much work still needs to be done in the area of sheep transport. Some of the topics that need to be looked at are appropriate resting periods and feed requirements, the effects of stocking density on injury and loss of balance and the circumstances under which high mortality occurs within individual loads.