DETERMINATION OF BODY-COMPOSITION IN GERM AN LANDRACE PIGS OF VARIOUSAGES BY MEANS OF MRI

German Landrace sows and male castrates of three weight groups ( 20, 5 0 and 90 kg liveweight) were scanned at five body regions. After slaug hter the left carcass side was totally dissected. Prediction equations were developed from image data and dissection results of 143 pigs. Th ese functions allow to predict lean and fat content of live pigs weigh ing from 15 to 105 kg. Coefficients of determination for total amount of lean and fat are very high in all weight groups (R(2) greater than or equal to 0.9). Lean and fat percentage can be estimated by a coeffi cient of R(2) greater than or equal to 0.8, with the exception of weig ht group '20 kg' (R(2) < 0.7). The prediction equations were then used to analyse lean and fat growth of 23 sows and 25 castrates of German Landrace during the fattening period from 9 to 23 weeks of age. The ca lculation of allometric coefficients indicates that female pigs have a significant faster lean growth but a slower fat growth than the castr ates. Originally developed for human medicine, MR Imaging has proved t o be a technique to determine body composition of live pigs with a hig h accuracy. Therefore it could serve as a reference for the developmen t of other techniques or to search for new measuring positions. Furthe rmore MRI offers new possibilities for the analysis of tissue growth, since individual growth curves of tissues, muscles and organs can be e stablished by means of repeated tomography in the same animals.