For thousands of years, perhaps ever since the domestication of cattle, farmers have favoured, and therefore selected, certain animals above others in an attempt to create a population of beasts best suited to their needs. Over time the sophistication with which breeding cattle have been selected has improved as technology and understanding has developed. In Great Britain today the genetic improvement of cattle makes use of the three main methods available: breed substitution, crossbreeding and within-breed selection. This paper concentrates on the last of these but recognises the importance of the first two in commercial practice. For example there has been considerable substitution of native British beef breeds with continental breeds during the 1960s and 70s and there is continued use of crossbreeding on dairy cows and in suckler beef production. Within breed selection and performance recording is valuable for the continued improvement of pedigree beef cattle and as a means for commercial producers to select suitable herd sires.