Animal breeding

Selecting for breeding animals with superior EBV in growth rate, egg, meat, milk, or wool production, or with other desirable traits has revolutionized livestock production throughout the entire world.

By "breeding the best to the best", employing a certain degree of inbreeding, considerable culling, and selection for "superior" qualities, one could develop a bloodline or "breed" superior in certain respects to the original base stock.

Such animals can be recorded with a breed registry, the organisation that maintains pedigrees and/or stud books.

The observable phenomenon of hybrid vigor stands in contrast to the notion of breed purity.

But this is highly unusual and difficult to do for most organisms, in whose populations all individuals harbor recessive, deleterious gene variants (alleles).