The use of liquid nitrogen as an alternative to mulesing

On 19 July 2019, the Schneider Group team based in Biella welcomed veterinary John Steinfort to learn first hand about his new method using liquid nitrogen as an alternative to mulesing. Mr. Steinfort is the inventor and promoter of the new sheep welfare process called ‘Sheep Freeze Brand’. We used the opportunity to speak with Mr. Steinfort directly to better understand the benefits of sheep freeze branding and answer the questions the wool supply chain has concerning the new method.

Why is Sheep Freeze Brand relevant to the wool industry?

With increasing consumer interest in animal welfare, many fashion brands and retailers have adjusted their sourcing requirements accordingly. This has led to a higher demand for mulesing-free wool exceeding the availability, especially for Australian non-mulesed wool. The Australian wool industry is working intensively on fading out the need to mules sheep through extensive breeding programmes. As these genetic programmes take time, it is important to develop other animal welfare solutions to ensure good welfare for sheep. Liquid nitrogen is one of these important developments.

What is the liquid nitrogen sheep breech method?

The method using liquid nitrogen called Sheep Freeze Brand, is a welfare improved alternative to mulesing. The goal of sheep freeze brand is similar to mulesing where excess skin at the rear of the sheep needs to be removed in order to prevent flystrike. Sheep freeze brand is performed through stapling the excess skin on the back of the sheep using an applicator and performing a cryogenic treatment in the affected area using liquid nitrogen. The freezing of that tissue lasts a few seconds and deactivates all nerve cells within the skin area. This ensures that the animal does not suffer in any way. The wrinkles present in the treated area are naturally absorbed without any discomfort to the animal.

Who developed the liquid nitrogen method?

Sheep freeze brand was developed by veterinary John Steinfort. Mr. Steinfort developed the concept of Sheep Freeze Brand (SFB) in 2008, imitating the freeze branding on racehorses and cattle. The process has been constantly tested and evolved and is now ready for commercial use.

Is the use of liquid nitrogen less painful than mulesing?

The sheep freeze brand procedure takes about 8 seconds – 4 applications of 2 seconds each. The procedure is very fast, so the animal will feel discomfort for about 4 seconds (one second for each application). The pain can be compared to a short stinging similar to when a wart on a finger or toe is removed with liquid nitrogen after which the skin then feels numb. In 2018, the method has been already tested on 25.000 lambs, followed by further applications in 2019. Compared to mulesing, growers observed a faster recovery of the lambs after the procedure by showing normal behaviour.

Are there more benefits of sheep freeze brand?

Trials to date have shown the faster growth rate of the lambs. The lambs under the sheep freeze brand trial have shown the post-procedure weight of the lambs improved at the same rate compared to lambs which were not mulesed. This indicates that the lamb was not under any stress or pain during the procedure. Under a standard mules (without pain relief) lambs have always initially had a weight set back due to the pain.

There is also an environmental benefit over a standard non-mulesed (NM) sheep. NM sheep remain at risk of flystrike and growers can face the necessity to use more chemical on the sheep to fight the fly. This is costly to the grower but also has a negative impact on the environment.

Finally, with the wool removed from around the breach, it can be expected that the wool quality will improve by reducing the risk of stain or coloured fibre entering into the wool clip. Less wool around the breach means less stain in the wool.

When is the liquid nitrogen method carried out?

The best time to carry out the practice is when the animal is still a lamb, in conjunction with the procedure of tail docking and castration. In addition, the procedure can make tail docking no longer necessary.

What are the costs of the liquid nitrogen method?

The process of sheep freeze brand costs $AUS 5 per lamb which is a much higher cost for growers compared to $AUS 1.20 for mulesing. However, trials have shown in the past, that lambs who have been sheep freeze branded grow on average 9% more wool compared to mulesed lambs. In addition, sheep freeze branded wool can be declared as non-mulesed or ceased mulesed and therefore may obtain a premium at auction.

How is sheep freeze branded wool being declared in the catalogue?

The Australian Wool Exchange (AWEX) has defined that wool originating from sheep who have been sheep freeze branded can be declared as non-mulesed (NM) or ceased mulesed (CM). This is based on the fact that no surgical cut is being made during the sheep freeze brand procedure.

Has the liquid nitrogen method been included in animal welfare standards?

As the procedure has only been released to the market recently, animal welfare standards such as RWS and ZQ have not yet recognised the process within their standard. Dr. Steinford and his team will seek further discussions with the standard holders to ensure well-informed decision can be made on whether or not to accept the method as a good welfare practice.
At the same time, there might also be concerns expressed by other wool growing countries who have benefitted from being mulesing-free.

Is pain relief needed for the procedure?

The pain caused by the liquid nitrogen method is not excessive. Experts and wool growers involved in the trials came to the conclusion that pain relief was not needed. However, further research is being undertaken to also test the method in conjunction with pain relief.

How is the market accepting the new method?

Large wool industry organisations such as the Australian Wool Innovation (AWI), Australian Wool Exchange (AWEX) and the International Wool Textile Organisation (IWTO) have accepted the method as a good alternative to mulesing and mulesing with pain relief to ensure good sheep welfare.
Brands and retailers who have their own animal welfare requirements are encouraged to study the new method and to read up on the available research. This will help to make an informed purchasing decision on whether or not to allow the sourcing of wool originating from sheep freeze branded lambs.

We hope you found this overview of the liquid nitrogen method useful. If you have any further questions, please feel free to contact us. We will be happy to help.


Image source: Chantel McAllister