EVALUATION OF INTRAMUSCULAR FAT-CONTENT IN THE LONGISSIMUS-DORSI MUSCLE BY VIDEO IMAGE-ANALYSIS AND DISCUSSION OF OBJECTIVES IN PIG BREEDING

Intramuscular fat content in the longissimus dorsi muscle has been decreased to a very low level of < 1 % at sire breeds Pietrain and Landrace B and to a considerable extent of < 2 % at dam breeds. The evaluation of intramuscular fat content by subjective scoring of marbling is only of little merit. The method of Video-Image-Analysis provides an higher agreement with intramuscular fat content got by ether extraction than subjective scores. Genetic correlations estimated on fattening performance traits from station testing show, that selection on high lean content and low feed conversion results in a lower intramuscular fat content, a decreased meat and fat quality and has an undesired effect on ''biological'' health of the animals. Therefore, future selection programmes should consider such traits like marbling and muscle fiber structure.