Growth and development of meat animals.

During the past 25 yr, animal scientists have learned much about the effects of environmental factors, nutritional treatments, the use of anabolic agents and genetic selection on growth of animals. Progress has been made in terms of body and carcass composition as well as a more fundamental understanding of growth at the cellular level. Current emphasis is directed towards action of hormones on tissue metabolism, factors regulating hormone secretion, mechanisms of synthesis and degradation of proteins and the energetic efficiency of protein and fat synthesis. The overall objectives are to control growth of animals with respect to rate and composition of gain and to improve the efficiency of growth.