A 4x4 latin square design experiment involving four treatments was conducted to evalute the effects of concentrate rations containing tallow on dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), neutral detergent fiber (NDF), total carbohydrate (TC), total digestible nutrients (TDN), calcium (Ca), and phosphorus (P) intake, milk production and composition. There were no differences among the treatments for DM, OM, CP, NDF, TC, TDN, Ca and P intake. Ether extract consumption was affected by the treatments. Fat corrected milk production and composition were not influenced by tallow addition to the diets, whereas the non corrected milk production was significantly increased. The addition of four percent of tallow showed to be the most economical.