5 minute read
Rethinking lamb castration
OSLA JAMWAL-FRASER, SENIOR AGRICULTURAL CONSULTANT, SAC CONSULTING
With the emergence of innovative new methods for lamb castration and tail docking, the Scottish Government is considering regulatory changes to accepted practices - potentially as early as 2028.
Currently, rubber rings (ringing) remain the most widely used technique. Introduced to the UK from New Zealand in the 1950s, it was once seen as a major welfare improvement. Today, however, concerns about pain - especially during castration - are mounting. Rubber rings can be applied legally up to seven days of age without anaesthetic. In Scotland, legal requirements differ from the rest of the UK, and from seven days to twelve weeks, rings may still be used provided a licensed local anaesthetic is administered. Until recently, options for older lambs were limited to clamping with a Burdizzo (up to 12 weeks) or surgical castration by a vet (over 12 weeks).
For flocks lambing indoors or on in-bye land, these methods are manageable - though pain responses can still lead to issues like mismothering. But for extensive hill flocks, ringing within seven days is often impractical. The Burdizzo is not as widely used as it could be, and vets are not routinely castrating older lambs. Until now, animal health and welfare inspectors have not focused on enforcement, given the lack of viable alternatives.
That is changing. With new techniques commercially available, a crackdown on illegal ringing without pain relief is likely. This shift may prompt producers to reassess their practices - and even question the wholesale need for castration altogether.
Some have long argued that castration is not essential for the prime lamb market.
Agriculture and Horticulture Development Board (AHDB) offers a helpful guide comparing the pros and cons of leaving ram lambs entire or using the short scrotum method. In Ireland and elsewhere, many prime lambs go to slaughter entire, with little pushback from abattoirs or consumers. Whether Scottish supply chains consistently accept entire lambs - or whether prices would suffer in some areas - is less clear. For slower-maturing native breeds, leaving lambs entire is not viable, and managing sexually mature animals poses logistical challenges.
Leading the shift toward improved welfare and compliance are two new methods designed by Numnuts and ClipFitter.
Numnuts, now licensed in Scotland for lambs up to 12 weeks old, uses a modified applicator that administers both a rubber ring and a dose of anaesthetic. The basic mechanism remains the same - constriction causes the testicles to wither and shed.
ClipFitter, also licensed for lambs up to 12 weeks, uses a clip (similar to a kitchen bag clip) that severs the spermatic cords in a similar way to a Burdizzo, while also completely severing the nerves to the scrotum blocking pain signals. The clip stays in place, cutting off blood flow until the testicles shed.
Results from preliminary SRUC research indicate that there were some welfare improvements with Numnuts with local anaesthetic. Licensed local anaesthetic (such as procaine and adrenaline) is available in Scotland through your vet for use with Numnuts, but further trials are needed to fully understand the benefits across different ages and systems. ClipFitter showed a greater welfare benefit, with clear reductions in both immediate and delayed pain responses. With support from the Scottish Government, SRUC has also produced a technical note (www.fas.scot/downloads/tn679castration-and-tail-docking-in-lambs) and training videos for those who want to find out more.
More research and industry experience are needed. Anecdotal evidence suggests that delaying castration and improving pain management may boost daily live weight gain - but no formal studies have confirmed this. Cost remains a major barrier. Both methods are significantly more expensive than traditional ringing, especially for small producers. Even with strong market prices, margins remain razor-thin, particularly in Less Favoured Areas (LFA). Most producers have no way to pass on added costs.
Despite this, adoption is growing. In 2025, 200,000 ClipFitter clips were sold in Scotland - a record, but still just a fraction of the 3.15 million lambs born each year. To support uptake, Highlands and Islands Enterprise (HIE) funded a pilot project in Shetland and the Black Isle, offering free access to equipment and training. The initiative will expand across the HIE region next lambing season, with SAC Consulting events and support from the Highlands and Islands Veterinary Service Scheme, where possible. No similar initiative currently exists for Numnuts.
Feedback from the pilot areas has been mixed. Many producers had positive experiences and plan to continue using ClipFitter. Others faced significant challenges. Though tempting to blame 'user error', without a robust support network, individual producers may struggle to gain the necessary skills and experience without risking animal welfare.
Projects like the HIE pilot are a step forward, but more is needed. Vets, too, are navigating unfamiliar territory - castration and tail docking are typically outside their routine remit, and troubleshooting these new methods is not yet part of standard practice.
There is no question that these new techniques have a place, and that the government is right to push for the eradication of illegal practices. But meaningful change requires more than regulation. It demands investment in research, training, and support.
In an era where 'data-driven decision making' is the policy buzzword, there is a risk of assuming that new techniques can simply be rolled out - and that crofters, farmers, and overstretched vets will just have to get on with it. If this is to be a positive shift, producers need time, resources, and tailored support to adopt new methods in ways that work for their animals and their businesses.
