Empty body chemical composition estimated from non-carcass parts in Belgian Blue double-muscled bulls

Properties of the non-carcass parts in combination with empty body and half carcass weight (EBW and CCW; kg) were used to generate equations for predi cting empty body chemical composition. Therefore, chemical composition of t he non-carcass parts and weight of the depot fatty tissues were determined on 18 Belgian Blue double-muscled fattening bulls. Very high coefficients o f determination (R-2) were found between the empty body composition and on the one hand the non-carcass parts composition and on the other hand the we ight of the fatty tissues. Fat in the empty body was most difficult to pred ict. The very high coefficients of determination are partly caused by the l arge variation in slaughter weight (309 to 723 kg). Therefore equations to estimate proportional composition of the empty body are discussed. Although R-2 values are strongly reduced, residual standard deviations remain very low and the precision of prediction is good. The proportion of protein is m ost difficult to predict, as it shows a very small variation. Estimations b ased on composition of the non-carcass parts are mostly a little more preci se than the estimates based on weight of the fatty tissues but as the latte r are much easier to determine, these equations will be move appropriate fo r practical use. Similarly the little improvement of the estimation based o n EBW instead of CCW, cannot account for the Extra costs and time to determ ine EBW. The results of the homogenizations have proven that there is very little variation in composition, despite the large range in slaughter weigh t. As the Belgian Blue double-muscled animals are very deviant from other b reeds, the equations found in this study can only be applied for this breed type.