Culling is the removal of an individual from further breeding consideration. It is NOT necessarily killing. Any dog spayed or neutered is culled & could be called a "cull," just like any animal who never has offspring technically is a cull. Culling is selecting breeding stock, be it natural forces or breeders who choose who will produce & who will not. Culling out newborn puppies is something breeders learned from observing nature & from experience with certain early seen traits that indicate future problems. (But culling out by breeders, unlike in nature, is done by humane euthanasia, not by starvation, competition & exposure.) Puppies are not normally killed "just" for color, despite widespread myths & rumours to the contrary. Puppies are usually euthanized for one of three reasons: a) the litter has an excessive number of pups in it, b) the pup(s) in question has a trait associated with serious defects than impair a normal life, or c) the breeder is unable to find suitable homes for the puppies in question. All are acts of extreme responsibility & no breeder should be condemned for acting responsibility toward his/her pups, dam and breed. Breeders who cull out at birth are not less feeling than those who, for whatever reason (& it's too often from ignorance or emotion) "choose" not to immediately seperate out excess & defective pups. Many would argue, in fact, that breeders who cull out are in fact are simply braver, & are acting from a deep love for the breed, the pups and the dam; for to have to euthanize lives you brought into the world is never less than a terribly heavy burden. Most breeders will be faced with the need to cull out newborns at some point & some breeders (e.g. Harlequin Dane breeders) face the issue often. Culling, however it is done, keeps the breed strong by selecting only the best individuals to parent the next generation. It is a necessary breeder's tool. Culling out newborns when to keep them would have bad effects on the pup itself, on the other pups, the dam &/or the breed itself is just one of the least pleasant burdens being a breeder brings. Culling in general is used by everyone who breeds...including nature. Again culling is the natural aftermath of selecting one animal for breeding over another. It's a necessary part of any breeding program & the "culls" are NOT lesser in any sense per se: I do hope we are now at a time in history we will no longer judge anyone, animals or women for that matter, based purely on their reproductive value.