Comparison of the Burdizzo and rubber ring methods for castrating and tail docking lambs.

The behavioural and plasma cortisol changes in groups of six lambs, five to six days old, were used to compare the acute effects of four methods of castration and tail docking: Burdizzo, standard sized and small rubber rings, and a combined method in which the application of a standard rubber ring was followed immediately by the application of the Burdizzo just distal to it. A control group was also included. Active behaviours such as foot stamping and restlessness increased markedly only after the treatments with rubber rings. Less time was spent in abnormal postures, and the increases in plasma cortisol were least after the combined method. It was concluded that the lambs treated by all the methods suffered considerable acute pain, for up to three hours in some cases, but that the combined method produced the least pain as judged by the behavioural and physiological indices measured, and that the small rubber rings produced more intense pain for a shorter time than the standard rubber rings.