COMPORTAMENTO ALIMENTAR DE NOVILHAS PRENHAS CLASSIFICADAS PELO CONSUMO ALIMENTAR RESIDUAL AJUSTADO PARA ACABAMENTO

The objective was to evaluate the performance and feed efficiency of pregnant heifers classified according to their residual feed intake adjusted for fat (RFIfat). Data from two feed efficiency tests, with a total of 273 Nellore heifers were utilized. Feed intake was measured by using the GrowSafe feeding system, and the stepwise methodology was utilized to identify which carcass trait should be utilized to calculate feed intake. The stepwise analysis indicated that subcutaneous fat thickness should be added to calculate the estimated feed intake. Heifers were divided into three RFIfat groups. For the majority of the feeding behavior traits, an effect (P<0.05) was observed according to the RFIfat classification. As the average intake per meal, feeding time in the trough, and visits per day to troughs had an effect of RFIfat group, it can be inferred that more efficient animals walk less to feed. Thus, low RFIfat heifers are more efficient as they spend less energy for feeding activities and, therefore, more energy is available for body weight gain.