Ingestive behavior of Gyr x Holstein cows grazing “Brachiaria brizantha” and Coast-cross pastures

Abstract

An experiment was carried out to evaluate the ingestive behavior of Gyr x Holstein cows grazing Brachiaria brizantha and Coast-cross pastures, in a continuous stocking system with variable stocking rate. A completely randomized experimental design with two treatments (pastures), each one with ten replicates, was used. The experimental period lasted 40 days, 25 for adaptation and 15 for three evaluations of 24 hours each, in each five days. The F test showed that the heifers grazing Brachiaria brizantha spent less time (5.49 hours) than those grazing Coast-cross (6.95 hours), along the day. Differences were not observed on the total time of rumination, of 8.72 and 8.82 hours for the pastures of Brachiaria brizantha and Coast-cross, respectively. The selective behavior of cows grazing Coast-cross allowed them to select high quality forage and to spend the same rumination time as those grazing Brachiaria brizantha. The results suggest that there is a compensatory mechanism between the grazing times and the bite rates that allow animals to regulate the amount of ingested forage.