two experiments were carried out to evaluate the dry matter, crude protein and gross energy digestibilities and the performance of rabbits fed simplified diets based on forages. in digestibility assay, 45 new zealand white rabbits with 1,550 kg of initial weight and 50 days old were distributed to a completely randomized design with 3 diets and 15 replications. three diets were used: a reference-diet and two simplified diets (one with alfalfa hay and other with upper third part of foliage cassava hay). coefficients of digestibility of dry matter, crude protein and gross energy were 50.06, 73.29 and 50.59% for the diet with alfalfa hay and 29.64, 46.96 and 24.52% for simplified diet with upper third part of foliage cassava hay. in performance experiment, 90 new zealand white rabbits from 35 to 70 days old were distributed to a completely randomized design with three diets, above specified, and 30 replications. the results obtained with simplified diets in the total experimental period of (35 to 70 days) were lower than those obtained with the reference-diet; however, more studies should be conducted with simplified diets to obtain maximum incorporation use of forages for the animal.