Experiments were carried out at Carimagua with the aim of investigating the effects of forage availability and stocking rate on the productivity of different classes of animal with in representative improved pasture beef production systems. In addition, a continuos grazing system was evaluated in an attemp to relate steer calf growth rates to other animal classes, such as weaned heifers, adult steers for fattening and cull cows.The experimental desings was completely randomized. The stocking rates were 1.38, 1.85 and 2.32 animals per ha and 0_64, 0.85 and 1.07 animals/ha for the wet dry seasons respectively. F or the first, a significant interaction (P 0.05) were found either between stocking rates of between animal classes; average weight gain was 137 g/animal/dia for this season.