Frequently asked questions

Numnuts is entirely unique. Nothing else exists that can provide targeted pain relief to lambs during tail docking and castration. Here are some of the questions we’ve been asked during the past 8 years.


Marking lambs usually involves both tail docking and castration. Numnuts has been especially developed for the combined procedure of docking the tail of male and female lambs as well as castrating male lambs with rubber ring. 

We aim to make Numnuts and NumOcaine available to approximately 500 Farmers, Marking Contractors and Vets in Australia (only) in 2019.  We are producing enough NumOcaine to deliver pain relief to approx 450,000 lambs in 2019.

The farms that have registered their interest and shown an intention to purchase Numnuts ahead of your marketing season will be first in line to receive the limited stock we will have available.  

Our online store will be open to purchase Numnuts from late June 19, we will email those registered and they can buy in advance. The stock will be sold on first come first served basis. 

Delivery of devices to farms will be from Mid August 2019. 

We hope to make the technology available in the UK and NZ in 2020. We are actively seeking UK Vet practices who wish to partner. 

The launch schedule is now available on our blog.from

Numnuts will be available on a ‘cost per procedure basis’. Numnuts will be competitively priced against current pain relief products.  

To find our how much it will cost you, please try our cost estimator tool:  

There are two components to Numnuts: a ring applicator tool and a local anaesthetic injector cartridge that locks on top of the ring applicator tool. The ring applicator tool will last for many seasons. The injector cartridge is replaced every 65 shots. The injector cartridge has two components that are joined just before use. This procedure ensures there is a new needle and a sterile bottle of pain relief drug ready to use in each new cartridge. The packaging has been carefully designed for operator convenience and for operator and lamb safety.   A new needle with every new injector cartridge helps minimise the risk to the lamb of infection and ensures that the needle remains sharp. This innovation is more humane than the common practice of using a single needle for 100s of animal injections, for instance during vaccination and some worm treatments.

During the first few seasons a veterinarian’s script may be required when purchasing the replaceable injector cartridge (which includes the local anaesthetic drug).  Regulations controlling the supply of the injector module may vary between countries. Further details will be provided on this website when country-specific details become available.

The withholding period for NumOcaine®  in Australia is 0 days.  

A trained operator can apply Numnuts in 2-3 seconds

We believe the marginal additional time taken to push the local anaesthetic injection plunger on the Numnuts tool is offset by the improved ergonomics and reduced RSI associated with using our unique innovative tool for applying rings to the tail and scrotum at marking.

Numnuts engineers worked beside veterinarians, stockpersons, shepherds and farmers to ensure that Numnuts is safe, fast and practical to use by animal handlers familiar with marking lambs.

The local l anaesthetic In Numnuts is a powerful fast-acting drug that blocks transmission of pain signals by nerves. The local anaesthetic is injected directly where the ring is applied to the tail and scrotum. The pain of ring castration and ring tail docking commences at these sites. LA is the ideal class of drug for reducing acute pain.  The marking ring disrupts blood flow to the tail and testicles.  Pain develops around 2 – 5 minutes later from loss of oxygen supply, and the acute pain associated with the procedure lasts 60-90 minutes. LA reduces the conduction of pain by nerves for a similar time frame. Local anaesthetics are therefore an excellent choice for reducing the acute pain when lambs are marked with a rubber ring.

In contrast NSAIDs have a slower onset than local anaesthetics. They act by a different pathway to reduce production of chemicals (prostaglandins) that provoke tissue inflammation and pain. NSAIDs are a good choice for reducing dull and chronic pain, once the immediate and most intense phases of pain have passed.

We have shown a significant improvement in lambs time to find their mother and suckling having had NumOcaine administered with rubber ring. Numerous reports from farmers also show that the lambs muster and can be herded back to the paddocks/ fields faster, with less dog intervention and less misadventure.

Most of the experts in this field feel it is unlikely that benefits from pain management during the aversive procedures at lamb marking will ever be measurable in terms of improved end production or profitability. Whatever temporary productivity setback a lamb might suffer without pain relief, will have been compensated for by the time it (or its wool) goes to market. That compensation is likely to come at the cost of poorer feed conversion, but under extensive production conditions, we simply do not have the instruments with which to measure this accurately.

The profitability the farmer will see is the knowledge that they are doing the right thing for their animals during necessary husbandry procedures while sustaining continued access to a sheep meat-eating and wool-producing consumer market that is showing an incresed interest in the welfare of the animals that produce the meat and wool that they consume.

Regulations controlling marking practices varies between countries. In Australia, animal husbandry practice guidelines recommend marking lambs between 2 to 8 weeks of age, whereas government regulations indicate that marking should, where possible, occur between 2 and 12 weeks of age. Numnuts is designed to be used on lambs up to 12 weeks of age.


Lambs over a 7days old must be given a local anaesthetic  prior to castration, which is of course what Numnuts delivers.

However, lambs more than 3 months old may only be castrated by a vet (Veterinary surgeons act 1966)

Numnuts has been designed for use on lambs held in the type of marking cradle commonly used in Australia and New Zealand. Numnuts can be used without a lamb marking cradle. When lambs more than 7 days of age are marked a cradle improves the ease with which lambs are held for marking. When lamb marking is carried out at 2-8 weeks of age an animal handling system like a lamb marking cradle is recommended.

Yes, the system has been designed to utilise the traditional rubber ring, which is a bloodless and highly effective, farmer-friendly method for castration and tail docking lambs that is used in many countries.

Numnuts does not alleviate all the pain a lamb experiences during castration and tail docking.  For a lamb, marking may be similar to the human experience of visiting a dentist. For a human, a filling or a tooth extraction, following injection of local anaesthetic, is usually not without some pain.  Similarly at present, pain relief provide by Numnuts does not abolish all the pain associated with marking. Numnuts reduces the pain lambs experience substantially when they are marked. Numnuts has been developed in collaboration with veterinarians and animal behavioural scientists at two world leading animal health and animal welfare research organisations; Moredun Research Institute and CSIRO with the goal of reducing the pain experienced by lambs at marking.

Numnuts is designed castrating and tail docking lambs with rubber rings. Ring and Remove’ is an option. A ring can be placed on the tail using Numnuts device and NumOcaine administered, then tail removed on the distal side of the ring. Efficacy of Ring and Remove has not yet been evaluated.

Numnuts is designed for marking lambs. NumOcaine is approved for calves – they will likely need more than one dose. No efficacy data currently exists. A future Numnuts device for calves is in future development pipeline.

Tail docking reduces soiling of wool with urine and faeces. This reduces the risk of sheep contracting the painful and potentially fatal disease fly strike and reduces the risk of carcass contamination in the abattoir. Castration reduces fighting between males, improves meat and wool quality and enables the farmer to selectively breed sheep for beneficial traits by use of superior sires.

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