Ingestive behavior of beef calves on oat and ryegrass pasture intercropped with vetch at different seeding rates

Abstract

The use of winter forage plants constitutes a procedure that optimizes cattle production, particularly in the subtropical region of Brazil. Understanding the relationship between forage species and grazing cattle, as well as their behavior within the environment, becomes crucial for a more efficient use of the forage. Therefore, the objective was to evaluate the ingestive behavior of beef calves in intercropped pastures of black oats, ryegrass, and vetch. A randomized block design was employed, with three area replications. The treatments resulted from the combination of ryegrass, black oats, and 0, 20, and 40 kg of vetch seed/ha. Twenty-seven Brangus calves kept under continuous grazing with variable stocking rates were used. Three daytime assessments of ingestive behavior were conducted. The forage systems did not influence the time spent on grazing, rumination, and other activities (P>0.05). However, as the grazing cycle progressed, the calves spent more time grazing and less time on other activities. The introduction of vetch into the forage mixture increased both the time and the number of chews during rumination (P<0.05). Towards the end of the grazing cycle, the calves needed to visit more feeding stations per minute and have a higher bite rate. Calves that grazed in higher vetch densities exhibited a greater number of steps between feeding stations, but only during the second period. The inclusion of vetch in conjunction with grasses only modifies the rumination patterns of calves, while the advancement of the phenological stage of the pasture leads to more evident changes in the ingestive behavior of grazing calves.