Comportamento diurno de bovinos leiteiros em pastagens de clones de capim-elefante anão na região da Zona da Mata do Estado de Minas Gerais

Abstract

The study was carried out at Embrapa Gado de Leite (Coronel Pacheco, MG), in order to evaluate the ingestive behavior of animals, forage quality and behavioral activities of animals with clones of elephant grass under intermittent stocking strategies, between December 2010 and April 2011. The treatments were the factorial combination (2x2x2) of two clones of elephant grass (CNPGL 92-198-7 and CNPGL 00-3-1), two light interception (LI) at the entrance of animals (90 and 95%) and two heights of post-grazing residues (30 and 50 cm), arranged in a completely randomized design with three replications. The lowering of the canopy was accomplished via direct grazing by crossbred Holstein x Zebu using the "Mob Grazing." Feeding behavior was assessed with use of esophageal fistula forage quality and intake of three sampling methods (whole plant, extruded and hand simulation of grazing). Animal behavior was observed during 10 o'clock from 10 to 10 minutes in the daytime. Clone CNPGL 92-198-7 was a higher bit rate (32,2 bits / min), and larger bit (0,61 gDM / bit) at the time of residue of 50 cm. The chemical composition of the fodder varied according to the sampling studied. The extruded sample showed higher values for crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), cellulose, lignin and in vitro digestibility of dry matter (DM) and values close were found for the manual method of simulating grazing. Clone CNPGL 92-198-7 presented better nutritive value under 90% light interception at the height of 30 cm residue after grazing. Shorter grazing was observed for clone CNPGL 92-198-7, since the clone was greater CNPGL 00-3-1 ruminating time for IL 90% and at residue 30 cm. The animals had difficulty in achieving low waste, which affect the nutritional value of forage consumed, because the increase in NDF, ADF, cellulose and lignin. Thus, it is recommended that the clone 92-198-7 for use under grazing, since the animals dispenderam shorter time for grazing, ruminating and idle while consuming the same.