ABSTRACT

Animal species vary in composition due to their stage of growth, nutritional history, and genetic base. This is significant for livestock producers, the meat industry, and consumers, because the economic value of meat-producing animals depends greatly on composition. Economic forces have reduced the fat content of livestock, in general, in response to consumer demands for more lean meat. To successfully assess body composition of both the live animal and its carcass, many procedures have been studied, and of these, linear measurements, including width, depth, length, and area, as well as weight, density, and visual shape, have been used separately and collectively with varying degrees of accuracy. More accurate techniques, such as nuclear magnetic resonance imaging, electromagnetic scanning, bioelectrical impedance, anyl-ray, computerized tomography, chemical analyses of body fluids, video imaging, and whole-body potassium isotope counting, exist. These techniques are usually ignored because they may be unreliable, very slow, very complicated, or very expensive to be practical or to serve as substitutes for dissection and chemical analysis when accurate composition is required for research. The following is a discussion of meat-animal composition and of linear dimensions used as means of assessing composition of livestock and their carcasses.