[Tim W]

Resistance----The ability of the sheep to resist the challenge of the worms – To inhibit their development and reduce the number of eggs laid

Resilience ---The ability of the sheep to continue to be productive whilst hosting a large worm burden which continues to lay eggs

Resilience is great but it means that the eggs are still being shed onto the pasture to breed/multiply and infest other sheep
Resistant ewes on the other hand kill worm eggs and reduce the worm burden for susceptible animals like young lambs

Showing no outward symptoms is great but a moderate worm burden still means slower growth rates etc

There is a school of thought that says have resistant mothers and a resilient terminal sire
Problem is that resistance/resilience only starts being shown by lambs when they get to 6 months old ----key i think (at the moment  ) is to have lambs slowly introduced to worms which helps them start to show their genetic resistance

We try to breed for resistance and also for animals that show resistance earlier in their lives

[Penninehillbilly]

Really intetesting discussion, thank you, looking forward to learning more  .
So do you just regularly do FECs then? If so do you do them yourself or does the vet do them?

[Tim W]

Really intetesting discussion, thank you, looking forward to learning more  .
So do you just regularly do FECs then? If so do you do them yourself or does the vet do them?

I do regular mob FEC to keep a picture of what is happening in which fields/farms ---prob. every 2 weeks in peak season but right now only this often for ram lambs or other at risk groups
 
For selecting animals for genetic resistance we do a single individual FEC somewhere between 5 & 7 months old . I get an independent technician to do this and only when we have run the mob counts up to at least 600/800 EPG (as with all traits you need to select under pressure or you don't know which ones can cope--eg. it's difficult to assess mothering ability if a ewe is in a pen and has little choice but to look after her lambs , you need to lamb her unattended in a field and observe if she looks after the lambs well )