Progeny Test and Individual Performance as Indicators of an Animal's Breeding Value

It has long been known by breeders that sometimes a few offspring indicate an animal's real breeding value more accurately than the animal's own appearance or performance does. The rediscovery of Mendelism and the discovery a little later (by Bateson and others) of complementary genes and of other epistatic relations among non-allelomorphic genes, provided a simple explanation for this. Occasionally there are cases where a single offspring furnishes more convincing proof of its parent's genotype than could ever be obtained by studying the parent itself. So far as color is concerned, this would be the case with a purebred red calf born in one of the black breeds of cattle.