Pre-planning and use of proper handling facilities are essential to avoid bruising of lamb carcasses. Catching, holding or lifting sheep by the fleece pulls on the hide of the animal and causes broken blood vessels on the surface of the muscles. It is important for producers to realize that any "grabbing" of the wool at all will result in significant bruising to the carcass.
British researchers have been studying the causes of bruising in sheep for many years. They found a high frequency of bruising in lambs sold through sales barns. A correlation was found between wool-pulling and bruising. The idea that a fleeced lamb was less likely to be bruised because it had some protection afforded it by its fleece is wrong. Bruising frequency was higher in fleeced lambs than in shorn lambs. Observers found that wool-pulling was the most frequently seen potential bruising event caused by human handling. Wool-pulling was observed at every stage of marketing of sheep; significantly more was seen during unloading and pre-sale handling, compared to post-sale handling and loading.
Handlers used wool-pulls and tail-pulls to change the direction of sheep, to restrain them, and to pull individuals from a group. Potential bruising incidents were higher during unloading compared to loading of sheep. At sales barns, over 11% of all potential bruising events observed were due to wool-pulls. Researchers observed wool-pulling at the following points:
* unloading trucks
- pulling the first few animals to start movement down the ramp
- lifting sheep by wool from upper deck to ground level
* loading trucks
- lifting sheep by wool from ground to upper deck
Another study at an abattoir concluded that 26% of bruising was attributed to handling and behavioural problems. Of this 26%, 1/3rd of bruising was caused by wool-pulling.
Figure 1. Illustration of damage to a lamb carcass caused by a handler grabbing the fleece.
Conclusion
The use of proper handling facilities and preplanning are essential to eliminate handling sheep by their fleece. Producers and truckers need to ensure that proper handling facilities are used to move sheep from one location to another.
References
Cockram, M.S. and Lee, R.A. (1991) British Veterinary Journal 147, 120.
Jarvis, A.M. and Cockram, M.S. (1995) Veterinary Record 136, 582.
Knowles, T.G., Maunder, D.H.L., and Warriss, P.D. (1994) Veterinary Record 134, 44.
Published 05/09/2008
Source: Ontario M. of Agriculture, Food and Rural Affairs
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