Hi Westy,
I've had very good luck by using eyesign to pair my breeders. I'll dispose of a bird or pair, if I continue to lose their youngsters. I've put youngsters from 3 differnet nests in 3 out of area lofts this year and flew the same babies here and lost them all. I can't see passing to someone else, birds that don't do well for me and other flyers.
This racing sport is about racing your best birds. Or breeding from your best birds to sell to other flyers. Honest breeders will/should never send out mediocre birds. We're supposed to be breeding/racing our best to make our wonderful sport better and better.
By the way, I bought two very good birds from Red Rose Lofts recently that I have high expectations in their breeding me some real tough long distance birds. The long distances is where you really test your birds to the upmost.
If your birds get sick then It's your own fault. You brought in a sick bird or did something wrong in medicating the flock.
Feed and Meds cost to much to be wasted on inferior birds.
All this is just an honest Irishmans opinion.
take care now, Ed