It definitly would and they might be doing it, but it is a very long process since it involve multiple breed. They would need to find out how to make children of the children resistant. They never breed the chickens they sell. They mix a+b= c than c+b= d where d is the final breed, but they always restart at c+b, never breed d with d or the result would be different.

I knew a guy which did that with bees for varroas and he lost over 90% of his bees. It took him years to come back, but his hives now deal better agaist the varroa, but he is a crazy one.