Backcrossing
Mating a crossbred animal back to one of its parent breeds.
Also: backcross
A backcross is the mating of a crossbred animal with an animal of one of the original parent breeds, for example an F1 heifer of zebu and taurine cattle mated back to a zebu bull. Backcrossing is used to recover more of one parent's traits while keeping a little of the other's. Repeated generation after generation, it can bring a single useful trait, such as hornlessness or a short, sleek coat for hot climates, into a breed while returning the rest of the animal to the breed's type. Each generation halves the share of the outside breed, so after four or five generations the animal is mostly of the target breed. Grading up is a form of repeated backcrossing.