ABSTRACT
Growth involves increase in size and changes in form over time. Change in composition, brought about by differential growth of the major tissues—muscle, fat, and bone--is a feature of growth. Genetic influences on growth and composition are manifest in breed differences in maturity type, muscling, rate of growth, and sex effects. Environmental factors affecting growth and composition include nutrition and management, which influence rate of growth and choice of slaughter weight relative to mature weight. Manipulation of growth to control composition depends on knowledge of the genetic and environmental factors influencing the relative growth of muscle, fat, and bone. Proportion of fat has a major influence on the proportion of muscle in a carcass; as fat increases, muscle decreases and vice versa. Beef producers are concerned with manipulation of growth and carcass composition in cattle. Superior carcass composition is shown by a high proportion of muscle, a low proportion of bone and an optimum proportion of fat.
