Knowledge of the genotype x environment (GxE) interaction is important for the optimum use of particular genotypes of animals in different production and breeding systems, especially for beef cattle, which are kept in both intensive and extensive environments. In the experiment, GxE for weaning weight in four breeds of beef cattle (Hereford, Aberdeen Angus, Beef Simmental, and Charolais) were tested using these definitions of environments: altitude, production areas, economic value of the land, less favourable areas (LFA), and performance levels of a breed within herds. It was found, that the most suitable definitions of environment were according to LFA and herd levels of performance. The results of this paper showed that the assignment of different breeds to specific environments and the routine evaluation of animals across all breeds are questionable under conditions in the CR. The evaluation within breeds could yield results that are more reasonable.