The Holstein and Belgian Blue double muscle type (BBDM) are two cattle breeds extremely different in extent of muscle proportion (Istasse, Van Eenaeme, Evrard, Gabriel, Baldwin, Maghuin-Rogister and Bienfait, 1990). In BBDM, the proportions of lean meat and fat are high and low respectively. Opposite trends are found in Holstein, the Belgian Blue dual purpose type (BBDP) being intermediate. This experiment was carried out to compare lipid metabolism in these 3 breeds.

Four bulls of these 3 breeds were used in a fattening trial. The initial weight was 340 kg. They were given a sugar beet pulp based diet supplemented with cereals, by-products and protein sources or vegetable origin. After a 145 days fattening period the final weight was 540 kg. Non esterified fatty acid (NEFA), triglycerides (TG) and cholesterol concentrations in the plasma were measured every 4 weeks during the fattening period. The plasma fatty acid composition was determined by gas chromatography. The 7, 8 and 9 ribs were removed at slaughter and cholesterol concentrations were measured in Longissimus Dorsi samples.