July 2022


I strongly believe that using genetics provides key management tools for much of the livestock sector. From the increasingly important environment perspective where work out of New Zealand for instance has indicated perhaps not surprisingly that sheep with significant worm burdens omit 30% more methane than otherwise. Methane output is high up governments’ climate control agendas and identifying sheep carrying these genes will likely be an important step in this direction. From a management perspective, reduced worm burdens within flocks also clearly have positive cost implications.

This year, a select subgroup within the LPRG, of which I will be part of, is looking at a further long-term research genetic project. Watch this space as this looks again to have potentially significant implications for sheep breeders. 

You will recall we were a founder member of the Lleyn Performance Recorded Group (LPRG) which has been researching the genetic heritability of intestinal worm resistance in sheep over the 7 years with Glasgow University. This is ongoing research. For the last three years, we have been blood testing for IgA serum. We believe that this project is now showing exciting real potential and is creating an important management tool for flock owners. 

Signet summarises the IgA results: “This has shown the antibody responses against the larval stage of an important member of the Strongyles family can be used as a biological marker for host response to infection”

“This potential phenotype provides a new way to identify genetic differences between sheep in their resistance to worm challenge. High levels of IgA have been shown to regulate both worm growth and fecundity – leading to a decrease in egg output”. The heritability looks to be encouragingly high at c.35% 

(https: //signetdata.com/technical/projects/parasite-resistance-serum-iga/)

Signet now has enough data points to have created an IgA serum EBV that can be utilised to identify these sheep. 

Rams that we are using are carrying Serum IgA EBVs. Not surprisingly I have purchased another ram this year again with a high IgA Serum EBV 

I am pleased to say that my shearling tups this year carry the new serum IgA EBVs in conjunction with other good index EBV scores. It is also worth pointing out that their sires are predominately Top 1% and high 5% index animals. Remember all our rams are purely grass fed from the very start. See Breeding Stock For Sale above and also on Sell My Livestock