We believe resilience has a huge role to play in the future of sheep farming.


With resistance to anthelmintic drenches becoming a more widespread problem and questions over the environmental impact of their use, the sheep sector needs to start looking for other alternatives to allow profitable farming to continue. Genetics is the answer.

The concept of resilience

Resilience to gastrointestinal nematodes (parasitic worms) is a relatively new concept for the UK but is a very simple one. A sheep defined as resilient is one which continues to survive and thrive, despite its parasitic burden. This is not to be confused with animals described as resistant to parasitic worms, which are defined as animals which have a lower parasitic burden, due to their ability to produce an antibody immune response against the parasite. Worms may also evolve resistance to the sheep`s immune response in the same way that they have evolved resistance to drenching, risking the creation of a “super worm”.

Resilience (or tolerance) to worms is possibly the “natural state” achieved over thousands of years of evolution. Worms don’t want to kill their sheep host but coexist with them. When we invented affective anthelmintics we took our eye off the ball when the genetic adaptation of sheep to worms was concerned. Now as wormers fail to work, we need to fall back on these natural traits. A sheep that is resilient to worms does not challenge the worms but copes with the infection and grows despite the worms. Good production is what we farmers want, and this way we don’t need to be concerned about worm egg counts or resort to blanket worm treatments. We can measure production and trust our sheep to cope with the worms, with only the poorer-performing sheep requiring treatment.

Innovate UK study

We were keen to validate our approach so took up the opportunity to work with, The Castle Veterinary Group, the Moredun Foundation and CIEL as part of Defra’s Farming Innovation Programme managed by Innovate UK. This has allowed us to dig deeper into worm resilience and how we can improve heritability in our flock.  Please follow this link to learn more.


Sheep farming is always a challenge and the future steep reduction in farm support is going to force change upon sheep producers. Simple systems with low inputs are likely to be the only option. Farmers will need to source breeding stock that can cope in these outdoor lambing systems. The team at Trefranck test their breeding stock against the rigours of real farming. The cull tags are applied ruthlessly. The results have been impressive to my eyes. Stock that become lame, suffer fly strike, poor mothers, wrong attitude, poor growth rates in the face of a worm challenge all leave the flock.

What is left is tough, capable, high health status stock. The latest injection of Te Whangai genetics has been the next step, lambs that are up and sucking straight away and with the trial work we have undertaken this 2022 lambing and rearing season, we have shown how worm tolerance from New Zealand can help farmers in the UK. Resilient Romneys they certainly are.

Tim Bebbington


The best thing I can say about Matts sheep is that they are great sheep for an old man. You just let them get on with the work themselves. No feed, just grass. They will outweigh my texel mules and grade just as good. The only problem we have is keeping flesh off the ewes post weaning.

Brendan Kelly

Sheep Farmer (Ireland)

We run about 900 Romney ewes on the South Coast of Cornwall and started keeping them 18 years ago. Our ewe flock spend most of their time grazing low input permanent pasture. Prior to buying Matt and Pippa’s rams we had felt that our ewes had lost some of their hardiness and increased in size which is also undesirable in our system. In my opinion this had happened because several ram studs now are operating as part of an arable system which doesn’t put their sheep under heavy pressure.

I was attracted to buying rams from Matt and Pippa as their sheep don’t get much access to clean grazing and they have a very heavy stocking rate, which gave me the confidence that their rams would come here and throw females that will really thrive. It is very clear in the 3 crops of lambs we have had from these rams that their lambs are outperforming our other lambs with the use of a lot less wormer.

The sheep at Trefranck are also very correct on their feet standing very upright. The wool type also stands out as being a lot less attractive to blow flies, something which is extremely important to us in our mild climate.

Edward Venning

Sheep and Beef Farmer (South Coast, Cornwall)

I approached Matt and Pip 3 years ago in regard to finding high health breeding stock, wanting a breed of sheep to run alongside a small contract shepherding business and a family farm consisting of a large intensive MV accredited flock, so having minimum inputs and costs was a very important factor. Having worked with Romneys in the past I knew what they were capable of, so with that, I bought a bunch of draft ewes with a couple of shearling tups with intentions of breeding replacement females to build the flock.

Grazing mostly old pastures and sheep sick ground the resilient genetics have paid dividends, lambs have seemed to thrive and grow whilst carrying a higher-than-average worm burden also meaning I can be confident on keeping ewe lambs as replacements knowing they will hold themselves under pressure. Matt and the teams relentless breeding program into selecting and producing these resilient genetics is really showing its potential and proving that it works.

Daniel Bower

Sheep Farmer and Contract Shepherd

I bought six rams from Resilient Romneys in 2020 to use over my Kent Romneys to improve the performance of my flock, and they have been doing just that. The progeny I’ve had since introducing the new genetics have been a consistently easy-lambing, strong, fast-growing, even-finishing lambs. I’ve hit the top price for Romney lambs at market sales on more than one occasion, producing healthy wether lambs from forage alone. I’ve reduced anthelmintic use to just one worming through the whole season. The female replacements I have retained in the flock have scanned higher than expected, boosting my outdoor lambing, grass-based system. Even when my stock were pushed incredibly hard during in a significant drought of summer 2022 these sheep lost no condition and came through to autumn strong and scanned well. I have bought females with Resilient Romney genetics for the past two years and I know they will suit my system. I look forward to further longer-term benefits of introducing Resilient Romneys genetics to Kent, helping me drive a profitable and sustainable sheep farming business. I will be increasing the area of my holding under a regenerative rotational grazing approach, growing the carrying capacity of the land with a higher stocking rate and utilising available forage more effectively. I’m particularly interested in how the worm tolerance of Resilient Romneys will assist with my objectives. I’m certain these sheep are a great solution to the environmental and financial challenges facing sheep production going forward.

Marie Prebble

Sheep Farmer and Shearer (Dover, Kent)

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