Hello! I am going to butcher some chickens in about two weeks and I have an abundance of ducks that I really need to get rid of! There are a few mutts, some blue swedes, buffs and a rouen. They are 22 weeks old and my question is: are they too old to butcher? I don't care for duck meat though a lot of my family does, but if the birds are going to be tough and stringy then I don't want to mess with it!! Thanks!