Abstract

The quest for indicators of performance in domestic animals is nothing new. In the first century A. D., Columella advised poultrymen to breed hens with five toes because (said he) such birds are better layers than those with the usual four toes. Ever since then, animal breeders have looked for some outward and visible sign of what performance they might expect from the animals under their care.

F. B Hutt

Proceedings of the World Congress on Genetics Applied to Livestock Production, Volume 2, Madrid, Spain, 179–185, 1974