Alliance meat company executives say increasing scrutiny by overseas retailers has influenced the firm's decison to put the practice of docking lambs' tails under the research spotlight.
Many New Zealand farmers remove part or most of the tail from their lambs to reduce the risk of fly strike from dags building up around the tail area.
But Alliance general livestock manager Murray Behrent says British retailers in particular are questioning the way farmers here are carrying out the practice, with some suggestion that tails are being docked too short.
The co-operative is starting a three-year trial on Southland and Canterbury farms to assess the productive, economic and welfare effects of docking.
Federated Farmers president Bruce Wills has been experimenting on his own farm, leaving either the full tail or most of it on his sheep, and has found it effective in reducing the incidence of bearings (vaginal prolapses) in pregnant ewes.
"(The trial) will be very interesting for many farmers," he says. "I'll be particularly interested in seeing what a more disciplined scientific approach brings up."