Lamb tail docking

Lamb tail length: no long-term effect on growth rate

New research has concluded that docking at a particular length or leaving the tail intact had no long-term beneficial or detrimental effect on lamb growth rate on farms with a low rate of fly strike.

Tail docking is a common practice among New Zealand farmers to help reduce dag formation and the risk of fly strike, but there is little objective information or research on the impact of docking practices on lamb growth from docking to slaughter and dag score.

Alliance Group’s General Manager of Livestock, Murray Behrent says there are many myths surrounding tail docking and its impact on lamb growth rate.

“We recognised a need to know what was true and what was not. The research has shown that docking to a particular length or leaving the tail intact has no effect on lamb growth to slaughter on properties and/or seasons with low fly strike incidence."

"It has provided objective scientific information about tail docking practices for our suppliers.”

“Alliance Group is continuing to work with our customers to further consider the welfare implications of the research and whether further investment and studies are required to meet the needs of our customers.”

The trial also explored the link between tail length and dag accumulation, a known risk for fly strike.

Lambs with tails left intact had more dags from one month after weaning onwards. These lambs and those with long tails (5-7cm) also took longer to crutch.

Beef + Lamb New Zealand (B+LNZ)’s Research Manager Geoff Ridley says there is a clear link between dags and fly strike.

“This research shows docking will be of most benefit in warmer, moist areas of New Zealand, where blowflies are more prevalent over a longer season. It’s something sheep farmers are already aware of, but these findings confirm and support our Code of Welfare, which permits docking when necessary to reduce the likelihood of fly strike.”

The research was carried out by AbacusBio on four farms in Southland, Canterbury, and Wairarapa in conjunction with Alliance Group, Sainsbury’s, B+LNZ, and the Ministry for Primary Industries’ Sustainable Farming Fund.

Additional analysis will identify whether there is an opportunity to increase processing revenue if tails are left longer, by generating additional product(s) for rendering or sale.

In the meantime, B+LNZ, MPI, and Alliance Group are reminding farmers to carry out tail docking in accordance with the Code of Welfare.