Docking, castrating and tagging lambs in New Zealand: rules and practical guide

🐑 The short version

One muster, several jobs — and rules attached to two of them.

For many small blocks, tailing day means bringing the ewes and lambs in once, checking each lamb over, docking tails, ringing ram lambs that are being castrated, applying identification tags and recording what was done.

Combining the jobs reduces repeated mustering and handling, but docking and castration are painful procedures and there are animal-welfare rules around how they can be carried out.

If you have never docked or ringed a lamb before, getting an experienced farmer, stock handler or vet to show you the first few is well worth doing.

❓ Is it required

Do lambs have to be docked?

No. New Zealand does not require you to dock a sheep's tail.

Docking is mainly used to reduce faecal soiling, dags and the associated risk of flystrike. On a small block where sheep can be checked frequently and crutched when necessary, leaving tails intact may be manageable.

The Code of Welfare says tail docking should only be undertaken where there is a significant risk of contamination or flystrike, or where not docking creates a significant animal-health, welfare or management problem.

If you do dock, however, there are rules governing both the method and the length of tail you leave.

Castration is also a management decision rather than something every ram lamb automatically needs. A ram lamb destined for slaughter before sexual maturity may not need to be castrated if it can be reliably kept away from females. Castration becomes more important if ram lambs will be retained, run with ewe lambs or adult ewes, or where unintended mating needs to be prevented.

⚖️ The rules — docking

What are the New Zealand rules for docking lambs?

For a sheep under six months old:

• The tail may be docked using a rubber ring or hot iron.
• You cannot simply cut the tail off with a knife or blade.
• The tail must be left no shorter than the distal end of the caudal fold.
• Whoever carries out the procedure must be experienced or trained in the method being used and able to recognise problems afterwards.

The caudal folds are the two folds of skin underneath the tail. MPI's practical guidance is to leave enough tail to cover the vulva in ewe lambs and approximately the same length in ram lambs.

For sheep six months or older, tail docking must be performed by a veterinarian or supervised veterinary student, and pain relief must be used.

The six-month age limit is a legal ceiling, not a recommended age for routine docking. MPI's Code of Welfare recommends docking before six weeks of age.

⚖️ The rules — castration

What are the rules for castrating ram lambs?

For sheep under six months old, a conventional rubber ring can be used by a competent person. When using a rubber ring, it needs to sit above both testicles and below the teats, with both testicles completely below the ring.

For sheep over six months old, veterinarian-authorised pain relief must be used throughout the procedure.

A high-tension band is different from the small conventional rubber rings normally used on young lambs. High-tension bands are mechanically tightened and require veterinarian-authorised pain relief at any age.

MPI recommends conventional rubber rings for younger lambs in preference to high-tension bands, and its welfare guidance says the best results from conventional rings are achieved up to about four weeks of age.

Pain relief is recommended for castration at any age. The New Zealand Veterinary Association also recommends effective and appropriate analgesia for both tail docking and castration. If you want to use pain relief when ringing your lambs, discuss the practical options with your vet beforehand.

📅 Timing

What age should lambs be docked and ringed?

There is a big difference between what the law allows and when the job should ideally be done.

• Docking: New Zealand's recommended best practice is before six weeks of age.
• Conventional ring castration: the Code of Welfare says the best results are achieved when lambs are only a few weeks old, particularly within the first four weeks.

Younger lambs are also much easier to catch, hold and return to their mothers.

There is no advantage in rushing a weak or unwell lamb through the job simply because the rest of the mob is being done. Check every lamb first. If one is not thriving or something does not look right, leave it out and decide what it needs before carrying out an elective procedure. If it turns out to need hand-rearing, our guide to orphan lambs and goat kids covers what comes next.

💉 Before the day

Check tetanus protection before docking.

Docking and castration can create an entry point for tetanus and other clostridial infections.

Whether your lambs already have protection depends on the ewe's pre-lamb vaccination programme and the lambs' vaccination history. If you are unsure of their tetanus protection, check with your vet before tailing day.

🧰 Preparation

What should I have ready on tailing day?

Get everything together before the sheep come into the yards:

• Ringer and fresh rubber rings
• Ear tags and the correct applicator
• Spare tags
• Tag marker if your tags are written manually
• Any animal-health products you have already decided to use
• Clean equipment and clean hands
• Somewhere clean to put equipment between lambs
• Your recording method — My Block Hand, phone or notebook
• Another person if possible

Use a small, secure pen with good footing and no gaps lambs can squeeze through.

Bring the ewes in with the lambs and keep mothers nearby while you work. One of the biggest practical problems on a small block is mismothering afterwards, particularly if lambs and ewes become separated in large or confusing yards.

Keep the job calm and organised rather than trying to process the mob as quickly as possible.

🔍 The health check

Give every lamb a quick health check first.

Once you have a lamb in your hands, take the opportunity to check it before doing anything else. Look at:

• Eyes — clear, without discharge; check that the eyelids are sitting normally rather than turned inward.
• Mouth — normal bite and no obvious sores or scabs.
• Navel — dry and healed rather than swollen, hot or weeping.
• Feet and legs — the lamb should be walking squarely without swollen or painful joints.
• Back end — clean, without significant scour or dags.
• Body condition and growth — note any lamb that feels noticeably smaller or lighter than its mates.
• Sex — confirm it rather than assuming.
• Ram lambs — make sure you can feel both testicles before applying a castration ring.

Record anything unusual while the lamb is in your hands. A note made now is far more useful than trying to remember which lamb had the swollen joint or funny eyelid that evening.

✂️ Technique

How do I position a docking ring?

Before releasing the ring, identify the caudal folds underneath the tail.

The ring must sit far enough down the tail that the remaining tail is not shorter than the distal end of the caudal fold. A useful visual guide is to leave enough tail to cover the vulva in a ewe lamb and a similar length in a ram lamb.

If you are unsure, leave more tail rather than less. Once a rubber ring has been applied there is no sensible way to correct a tail that has been docked too short.

🔴 Technique

How do I ring a ram lamb?

First make absolutely sure you can feel two testicles in the scrotum.

Place the conventional rubber ring around the neck of the scrotum so that:

• both testicles are completely below the ring;
• the ring sits below the teats;
• neither teat has been caught; and
• the ring is properly seated.

Check again by feel after releasing the ring. It takes only a few seconds and is much easier to correct immediately than later.

If you are unsure about the anatomy or positioning, have someone experienced show you. This is one of those jobs that makes considerably more sense once you have seen it done correctly.

🏷️ Identification

How should I tag the lambs?

Sheep are not NAIT animals. New Zealand's NAIT individual identification and movement-recording system applies to cattle and deer, so your lamb does not need a NAIT RFID tag and you do not register individual sheep in NAIT.

You can still tag lambs for your own management — and for a small flock it can be extremely useful. A simple tag can let you record:

• which ewe produced the lamb;
• singles, twins or triplets;
• sex;
• birth year;
• treatments and health history;
• growth or performance;
• breeding animals; and
• animals being retained or sold.

Follow the tag manufacturer's instructions and avoid the cartilage ridges and major blood vessels in the ear. The New Zealand sheep welfare code specifically recommends taking care around both when fitting an ear tag.

Write or scan the tag number into your records when you apply it, rather than planning to remember all the numbers afterwards.

⚠️ The one that catches people

There is one NAIT rule sheep owners can still encounter.

Although sheep themselves are not individually registered in NAIT, there is an additional requirement if you also farm cattle or deer.

If cattle or deer are present at your NAIT location, the PICA must declare the other relevant farmed species there — including sheep, goats and pigs. Each year, by 31 July, you need to record how many of those non-NAIT animals were at the property on 30 June.

So a lifestyle block with only sheep does not suddenly need a NAIT account because it has lambs. But a block already operating a NAIT location for cattle or deer needs to include its sheep and other relevant species in that annual declaration.

🩹 Aftercare

What should happen after tailing?

Once each lamb is finished, return it to its mother as soon as practical. Put the mob somewhere clean where you can observe them without having to muster them repeatedly.

Some pain-related behaviour immediately after docking and castration is expected. What matters is that lambs settle, mother up and return towards normal behaviour rather than deteriorating.

Check the mob carefully during the hours after tailing and continue checking them daily over the following days and weeks. Watch for:

• a lamb that does not mother up;
• failure to suckle or graze normally;
• marked or worsening depression;
• excessive swelling;
• bleeding;
• discharge or a bad smell;
• flystrike;
• abnormal movement or obvious pain;
• stiffness;
• difficulty opening the mouth or a rigid jaw;
• any lamb that simply looks increasingly unwell.

The tail and scrotum below conventional rubber rings will progressively dry and shrivel before eventually separating. Don't pull them off.

📋 Paperwork

Do I need paperwork when sheep leave the property?

Although sheep do not have individual NAIT records, Animal Status Declarations still apply to sheep and lambs. An ASD is required when sheep or lambs:

• move from one property to another where there is a different person in charge;
• go to a saleyard; or
• are sent for slaughter.

The declaration provides the next person in charge — and ultimately the processor — with relevant animal-status and treatment information. That is separate from NAIT tagging.

📝 Records

What should I record on tailing day?

The record is what turns tailing day from a job you completed into information you can use next year. At minimum, record:

• the date;
• which lambs were docked;
• which ram lambs were castrated;
• which lambs were deliberately left entire and why;
• tag numbers;
• the dam against each lamb if known;
• any animal-health product or treatment given;
• any abnormality found during the health check; and
• anything that needs following up.

That might include a light lamb, an inturned eyelid, a swollen navel or joint, scour, only one testicle palpable, a lamb left untreated because it was not thriving, or anything unusual during recovery.

Next spring those records give you something to compare against. You can see which ewes consistently raise strong lambs, which lambs needed intervention, how old your lambs were when you tailed them and whether anything about your system should change.

📲 In the app

How My Block Hand can help.

Tailing day creates exactly the sort of information that is useful now but easily disappears into a notebook afterwards.

In My Block Hand, you can keep the lamb's tag number, dam, treatments and health notes attached to the animal's record rather than scattered between the shed, your phone and your memory.

Record anything found during the health check while the lamb is in front of you, and create any follow-up job or reminder immediately. That way the light lamb you wanted to recheck, the ewe whose lamb had an issue, or the animal left entire does not disappear back into the mob and get forgotten.

Next season, those records are still there.

🚧 Where this guide stops

What this guide cannot do for you.

This guide provides general information for New Zealand lifestyle-block owners. It is not veterinary advice and it cannot substitute for seeing the procedure performed correctly.

If you have never docked or ring-castrated a lamb, get an experienced person to show you the first few.

Your veterinarian is the right person to talk to about pain relief, tetanus protection, unusual anatomy, sick or weak lambs, and anything during recovery that does not look right.

📚 Further reading

Where the information on this page comes from.

• MPI — Guide to the Animal Welfare (Care and Procedures) Regulations: the under/over six months split for docking and castration, permitted methods, the caudal-fold length rule, and the high-tension band requirement at any age.
• MPI — Code of Welfare: Painful Husbandry Procedures: when docking is justified, the recommendation to dock before six weeks of age, and best results from conventional rings in the first few weeks.
• MPI — Code of Welfare: Sheep and Beef Cattle (PDF): ear-tagging care around cartilage ridges and blood vessels.
• MPI — Further information on sheep tail-docking regulations (PDF): the distal end of the caudal fold, the vulva-cover guidance, and the infringement fee.
• New Zealand Veterinary Association — Tail docking and castration in lambs (PDF, Feb 2025): the analgesia position.
• OSPRI — Registering animals in NAIT: NAIT applies to cattle and deer, and the annual 31 July declaration of other farmed species at a NAIT location.
• MPI — Animal Status Declarations: when an ASD is required.