With lambing underway across the country, the Ministry for Primary Industries (MPI) is reminding sheep farmers and contractors of the animal welfare requirements for tail-docking.
"Tail-docking regulations came into effect in May 2021, alongside others covering a variety of surgical procedures carried out on a range of animals," MPI's director of animal health and welfare Dr Carolyn Guy said.
"The regulations align with what has been considered good practice for many years."
Although tail-docking, or tailing, was a common farming practice, it was important to keep in mind that it was still a significant procedure for the lamb, Guy said.
Only a hot iron or rubber ring can be used on sheep under six months of age.
"Don't dock any shorter than the distal end of the caudal fold. This is the point where the two folds of skin attach on the underside of the tail," Guy said.
"It is recommended you aim to leave enough tail to cover the vulva in ewes, and a similar length in rams."
For sheep over six months old, tail-docking must be done by a veterinarian, using pain relief, Guy said.
MPI director of animal welfare Dr Carolyn Guy. Photo / Supplied
"Most people will already be doing it this way. However, it will be a change of practice for those who have previously docked very short or taken the entire tail off."
The length requirement is based on the code of welfare for painful husbandry procedures.
It's in line with requirements in assurance or verification programmes such as the New Zealand Farm Assurance Programme and NZ Merino's ZQ Programme and is comparable to requirements in other countries.
Guy said it was important to balance the benefits of tail-docking with the benefits of having a tail.
Tails had an important function that allowed sheep to flick away faecal matter, which helped prevent dags, Guy said.
"They also contain lots of nerves and blood vessels. Research shows that the shorter a tail is docked, the more painful it is for the animal."
The regulation applied to the tail docker, the owner and every person in charge of the sheep at the time of docking, so it was important that everyone was aware of the rules, she said.
"If you use a tail-docking contractor, make sure they're aware of the rules. Have a chat about length as part of your tail-docking planning.
"If you're unsure of the tail docking regulations, check the MPI website or talk with your vet."