A mechanistic dynamic model of beef cattle growth, which simulates the evolution of proteins and lipids in the body through synthesis and degradation equations, has been developed (see Hoch and Agabriel, 2003, for description). The present paper deals with the evaluation of this model by studying its behaviour and the simulated evolution of processes involved. A sensitivity analysis of model results to parameter values was performed. This model was then applied to three different data sets concerning various animal types. A comparison between continuously and discontinuously growing animals was also made. The model is shown to give a good prediction of metabolic processes such as synthesis, degradation and maintenance energies. The analysis of sensitivity to parameter values demonstrates the key role of parameters related to protein synthesis on the simulation of empty body weight. Calibration and validation on data sets representing two distinct feeding regimes for the same animals show that the model can take compensatory growth phenomena into account. Different maturing rates of animals generate different responses from the model in terms of protein synthesis.