Compositional data on Belgian Blue double-muscled bulls$^{1, 2}$

Compositional data of 17 Belgian Blue double-muscled bulls with empty body weight between 276 and 669 kg were analysed. Body composition only changed slowly and linearly within the investigated live weight range. Water, protein, fat and ash in the empty body varied between 65.8 and 72.0%, 18.9 and 21.2%, 3.5 and 9.7% and 3.0 and 4.% respectively. The chemical fat con- tent in the empty body was remarkably low. The percentage of accreted energy as protein always remained higher than 50% of the total accreted energy, which is much higher than generally reported in literature. Caloric values for protein and fat were: 22.91 (± 0.90) MJ .kg -1 and 38.74 (± 1.53) MJ.kg -1 respectively. Carcass protein contained on average (in %) 8.8 Asp, 15.6 Glu, 5.3 Pro, 7.7 Gly, 6.6 Ala, 7.5 Leu, 7.4 Lys and 6.5 Arg, while the protein in the non-carcass parts contained (in %) 8.0 Asp, 12.7 Glu, 8.8 Pro, 15.1 Gly, 8.0 Ala, 6.6 Leu, 5.6 Lys and 7.2 Arg. The protein composition proved to be rather constant for the considered live weight range. double-muscling / body composition / bulls / Belgian Blue breed