Produção animal e de forragem em pastagem nativa submetida a distintas ofertas de forragem

This trial was conducted in natural pasture area of the Agronomic Experimental Station of Universidade Federal do Rio Grande do Sul (Porto Alegre-RS), from 10/25/2000 to 09/13/2001, with the objective of evaluating the treatments: 8%, 12%, 16% of dry matter allowance (DMA) over the year, 8% of DMA at spring and 12% at summer, autumn and winter (8-12%); 12% of DMA at spring and 8% at summer, autumn and winter (12-8%) e 16% of DMA at spring and 12% at summer, autumn and winter (16-12%), using steers on continuous grazing with variable stocking rate. The experimental design used was blocks randomised with two replications. The biggest average daily weight gain over the year (0.466 kg/an/day) was obtained in the increased DMA treatment. This treatment, also, was the only management the animals increased weight at winter. The animal production/ha was smaller in the 16% and 16-12% treatments. The DMA changing over the seasons, as a procedure to manipulate the vegetation structure and composition to increase forage production and average daily weight gain was efficient, and its effect upon the forage and animal production go on all the seasons.