Abstract

It is generally accepted that tail docking is beneficial in farming systems where sheep are predisposed to dag formation and flystrike, but that it is a stressful procedure. Although there have been many studies of tail docking, relatively few have looked at the effects of different tail lengths. The incidence of flystrike depended on tail length, being least in medium-, and greatest in short-tail docked sheep. Short-tail docked ewes had higher rates of carcinoma of the vulva and short-tail docked lambs had a greater incidence of rectal prolapse. In some cases, increased tail length was associated with increased dags, and with longer tails crutching and shearing effort was greater. There apparently have been no studies documenting the effects of docking at different lengths on the welfare of the lamb at the time of docking, on muscle anatomy, or on defecation and urination. Furthermore, the results obtained in some studies were confounded by differences in breed (e.g. Merino) and mutilations (e.g. mulesing), which question the validity of extrapolating their conclusions to New Zealand conditions.

MW, Fisher, NG Gregory, JE Kent, DR Scobie, DJ Mellor, and JC Pollard

Proceedings of the New Zealand Society of Animal Production, Volume 64, Hamilton, 293-296, 2004