Elephant grass under grazing. II. Factors affecting dry matter losses and utilization

Abstract

This study attempted to quantify dry matter (DM) losses and utilization during grazing of Pennisetum purpureum Schum. The pasture was grazed at three periods: beginning, midlle and end of Summer; grazing was done in two stages: a. experimental grazing, at 12; 8 and 4% of live weight (LW) of grazing pressure (GP); and b. complementary grazing. On the experimental grazing, losses were evaluated in %LW and in kg/ha; in the complementary grazing only in kg/ha. Losses in the experimental grazing averaged 1.14% LW or 736 kg/ha, and in the complete grazing was 1,124 kg/ha. All factors linked to accumulated DM affected negatively (P < 0.05) the losses, and factors linked to total DM affected positively. The major factors to affect losses was height of the pasture. On average the total DM present was 6000 kg/ha, of which 73% were accumulated during the previous resting period, 51% of this were consumed and 26% lost. In order to minimize losses one should induce lateral tillering and fast growth to obtain high disponibility of grass.