Meat processor and exporter Alliance is launching a research trial to get to the bottom of the practice of docking lambs' tails.
It is usual on New Zealand farms to remove lambs' tails as an animal welfare measure, to reduce the risk of fly strike from dags, or dirty wool, building up around the tail area.
However, the Alliance Group says retailers in international markets are demanding more evidence that practices such as tail docking are justified.
Alliance says there is not a lot of objective information available on the benefits or otherwise of docking.
So it is starting a three-year trial on Southland and Canterbury farms to measure the productive, economic and welfare effects of shortening lambs' tails to different lengths or leaving them intact.
The co-operative says it will be the first research of its kind and will have support from the Government's Sustainable Farming Fund, the British supermarket group Sainsbury's and Beef and Lamb New Zealand.