There will be times when culling is in the best interest of the chick i have had to this with baby chickens, turkeys, ducks and geese. Somtimes it is best to wait take for instant my goose Mongo he was born blind other then that he gets along perfectly fine also have a cornish cross who had splay leg after isolating her from the others in a hospital pen and cutting down on her feed she made a full recovery now 18 weeks later she is doing wonderful and is running yes a cronishX running around with the rest of my chickens. When it comes to ones that I know will not be able to make it no matter what I find it the easiest to break thier necks if done properly they go real fast. You should never make one suffer if you get too many roos rehome them I am sure there are plenty of people on this board who would scoop them up. Or place an add somewhere. If the chick is healthy it is your responsiblilty to find a decent home for them if they are unwanted.