Capim-marandu sobressemeado com forrageiras de inverno: comportamento ingestivo de novilhas F1 Holândes x Zebu

Abstract

The characterization of the overgrazed pasture when grazed by cattle is necessary so that we can efficiently manage the harvest of the forage produced. The objective of this work was to evaluate the ingestive behavior of F1 heifers Holstein x Zebu, grazing marandu grass irrigated in exclusive cultivation or overestimated with combinations of winter forages. In a completely randomized design, subdivided plots scheme, with three replications, three types of pastures were studied: marandu grass in exclusive cultivation; marandu grass overlain with mixture of white oats, black oats and ryegrass and marandu grass overshadowed with mixture of white oats and legumes, white and red clover, over three cycles of grazing (August, September and October). Heifers remained longer grazing on oat and ryegrass pastures (8.95 h) or oats and clover (9.38 h) than on exclusively marandu grasses (7.41 h). In relation to the time, grazing time was higher during daytime and in pastures overgrown with oats and ryegrass (7,63 h) or oats and clover (7,96 h) than in exclusively cultivated marandu grasses ( 5.96 h). More intense pasture activity was observed between 10 and 17 h, demonstrating a greater adaptation of mestizo animals to the heat stress environment of the tropics. The highest total number of daily bites was observed in the overgrazed pastures (35,468 and 38,799 bites / day) in relation to the exclusive marandu grass (27,819 bites / day). The overgrazing of winter forages in Marandu grass pastures modifies the pasture structure influencing the ingestive behavior of crossbred heifers on grazing. F1 heifers Holstein x Zebu concentrate the grazing activities during the day, prolong the time spent in grazing and increase the total number of daily snacks when compared to grazing in exclusive pasture of marandu grass.