Breeding and Selection

Abstract

Breeding of sheep makes use of the science of genetics - how different features of an animal are inherited by its offspring. Robert Bakewell (1725-1795) was a pioneer in livestock improvement in spite of the fact that he did not understand genes or how they were passed on to the progeny. His work was the stimulus for the development of a number of breeds as well as for the improvement of existing breeds where selection emphasis was placed on conformity to a visually desired type that was the hallmark of the breed and an indicator of its productivity. However, since the advent of the science of genetics, visual observation of animals has been largely replaced by measurement, calculating breeding values and making predictions of the outcome of different mating systems. This has resulted in the development of powerful selection tools (Kinghorn et al., 2002) that have changed the production capabilities of many animal populations quite dramatically (Simm, 1998).