Canopy structure and foraging behavior associated with phenological stages of winter forage

Data from eight experiments were jointly analysed to characterize the ingestive behavior, displacement patterns, use of feeding stations and the dynamics of meals of beef heifers in different phenological stages of winter forages. The experiments included 360 heifers, with initial age of eight months and average body weight of 145.0 +/- 17 kg. The grazing method was put-and-take stocking with variable number of animals. Grazing time, duration of meal and interval between meals were similar in the morning shift, regardless of the phenological stage. At the vegetative and pre-reproductive stages, in the afternoon, meals were longer. The average daily gain was greater at pre-reproductive being associated with the duration of the meal in the afternoon shift. Heifers change their ingestive behavior, bite rate, duration of meals, interval between meals, patterns of forage selection and number of steps per minute according to phenological stages and evaluation shifts in order to maintain a similar bite mass.