aiming to identify which commercial broiler lines behave better in terms of productivity in lowland tropical tropics, the ross 308 and cobb 500 lines were evaluated. therefore 160 one day aged individuals were evaluated, 80 per line and 40 for each sex, in order to assess their productive parameters, in a fully randomized design with four treatments, four replicates of ten individuals per treatment were evaluated in order to assess the behavior between the variables feed consumption, weight gain and feed conversion (g) for the initial and final fattening stages. the experimental data were studied by variance analysis and a duncan multiple test. the appropriation lines analysis (detailed budget) method was implemented for the economical analysis. for the food consumption variable in the initial fattening stage, significant differences (pr> f = 0, 05) between treatments were found, contrary to the weight gain and feed conversion variables, where no significant differences are reported (pr> f = 0,05). for the final fattening stage, for the feed consumption and weight gain variables, significant differences (pr> f = 0, 05) were found; while for the feed conversion variable, no differences were detected. in economic terms, it was determined that the t1 (cobb males) was the most efficient.