At CIAT’s Quilichao substation, Colombia (03o06’ N, 76o31’ W; 1700 mm; 990 m.a.s.l.; 24 0C), you half the production of milk and their constituents in cows ¾ Holstein of medium production in a program of restricted grazing of C. argentea mature and young, in a Simple Balanced Design Crossover with 6 cows Holstein in two treatments: (T-1) the grazing witness only in grass of Brachiaria decumbens; and (T-2); the T-1 but a period of 02 h/day grazing the C. The evaluation was carried out in two phases: (1) C. mature and (2) C argentea young, with a duration of 28 days each one. Each phase, it was measured in two periods of 14 days (7 adjustment:7 measurements). The evaluated variables were: Production of milk and their components, being not significantly different (P>0.5) between the treatments while the consumption of leguminous if I affect significantly (P>0.5) the levels of urea (mg%) in the milk and in the blood, where the levels of urea fluctuated between 14.9 mg% and 18.7 mg% possibly associated to a rebalanced among ammonium liberated in the rumen and necessary energy for the synthesis of microbial protein. The readiness of MVS vanes between treatments and phases with a level of offer of the gramineous one that seemed to limit the production. In both phases the cows 50% of the time remained consuming leguminous, estimating the time of effective shepherding in the morning in half hour and in the afternoon, respectively.