LAUSR

The objective of this study was to evaluate the ingestive behaviour of steers grazing Brachiaria brizantha cv. Marandu and in feedlot regimen in Brazil. Fifty crossbred steers, with an average weight of 275 ± 8.18 kg, were distributed in a completely randomised design with five treatments and ten replicates per treatment (mineral supplementation, nitrogen supplementation, and concentrate supplementation at 0.1 and 0.2% of body weight and under feedlot conditions). Ingestive behaviour was assessed every 5 min for 24 h. No difference (P > 0.05) was found for grazing time among grazing systems. Conversely, rumination, idle, feeding, and chewing times showed differences (P < 0.05) only for feedlot animals. The time spent feeding at the trough was higher (P < 0.05) in animals receiving concentrate supplementation. The bite rate and the number of bites per day were similar (P > 0.05) among grazing systems. Feed and rumination efficiencies of dry matter and neutral detergent fibre corrected for ash and protein showed differences (P < 0.05) only in feedlot animals. Therefore, ingestive behaviour of steers varies with the raising system. Overall, feedlot animals showed better performance than grazing animals did, most likely due to longer rest periods.