Submitted to: Encyclopedia of Animal Science
Publication Type: Review Article
Publication Acceptance Date: 10/27/2003
Publication Date: 11/10/2004
Citation: Mitchell, A.D., Scholz, A.M. 2004. Body composition: Indirect measurements. In: Encyclopedia of Animal Science. W. Pond and A. Bell (eds.), Marcel Dekker, Inc., NY. p.166-169.
Technical Abstract: Historically meat animals have been evaluated and selected using subjective methods based primarily on visual appraisal. However, a variety of indirect methods for the measurement of body composition are now available to assist in the evaluation process. Most of the newer techniques are based on tissue interaction at the atomic or molecular level that result in signals that can be analyzed quantitatively. Advances in techniques for body/carcass composition analysis are based on the development of electronic/computer based methods, thus avoiding destructive, labor intensive or subjective approaches. This entry discusses deuterium oxide dilution, neutron activation, potassium-40 analysis, bioelectrical impedance, total body electrical conductivity, dual energy X-ray absorptiometry, magnetic resonance imaging, and computer tomography as methods of determining body composition. In general, the choice of a particular technique will depend on the purpose or application, technical aspects (accuracy, reliability, and the type of information needed) and practical aspects (cost, portability, need for restraint or anesthesia, speed, ease of use or training required, safety, and size of the animal to be measured).