The application of digital imaging techniques in the in vivo estimation ofthe body composition of pigs: a review

Calorimetry and comparative slaughter measurement are techniques widely use d to measure chemical body composition of pigs, while dissection is the sta ndard method to determine physical (tissue) composition of the body. The di sadvantage of calorimetry is the small number of observations possible, whi le of comparative slaughter and dissection the fact that examinations can b e made only once on the same pig. The non-invasive imaging techniques, such as real time ultrasound, computer tomography (CT) and magnetic resonance i maging (MRT) could constitute a valuable tool for the estimation of body co mposition performed in series on living animals. The aim of this paper was to compare these methods. Ultrasound equipment entails a relatively low cos t and great mobility, but provides less information and lower accuracy abou t whole body composition compared to CT and MRI. For this reason the ultras ound technique will in the future most probably remain for field applicatio n. Computer tomography and MRI with standardized and verified application m ethods could provide a tool to substitute whole body analysis and physical dissection. With respect to the disadvantages of CT and MRI techniques, the expense and the lack of portability should be cited, and for these reasons it is most likely that in future such techniques will be applied only in r esearch and breeding programs. (C) 1999 Elsevier Science B.V. All rights re served.