Nutrient Intake and Ingestive Behavior in Lambs Fed Hay and Concentrate

This study was carried out with the objective of evaluating the changes in the ingestive behavior and in the intake of crossbred Santa Inês lamb fed Tifton 85 hay associated to levels of concentrate supplementation. Twenty lambs, weaned and uncastrated, with initial body weight (BW) of 20.3 ± 3.6 kg were distributed in four treatments with Tifton 85 hay exclusive or associated with concentrate levels (0.0, 6.6, 13.3 and 20.0 g kg-1 d-1 BW), in a completely randomized design with five replicates. The ingestive behavior was evaluated through feeding, rumination and idleness parameters, feeding and rumination efficiencies, as well as dry matter (DMI), neutral detergent fiber (NDFI) and crude protein (CPI) intakes. Supplementation did not change the NDFI, but linearly increased the DMI and CPI expressed in g day-1, g kg-1 day-1 BW and g kg-1 day-1 BW0.75. Despite of this the regressions obtained for time spent with feeding, rumination and total chewing showed decreasing behavior when expressed in minutes day-1 or in minutes kg-1 DM. The feeding (g hour-1) and rumination (g hour-1 and g cud-1) efficiency of DM and CP also increased linearly. The higher levels of supplementation provided less time spent with feeding and rumination activities and, consequently, longer time with idleness.