Padrão de consumo e comportamento alimentar durante o teste de eficiência em machos Nelore

The present study aimed to evaluate feed intake and behavior during the efficiency test of Nellore males. Efficiency test was conducted from June to October of 2012, during 119 days. Registers of 85 Nellore males, with initial averages age of 270 ± 23 days and body weight of 239 ± 41 kg were used. Animals were fed ad libitum at GrowSafe System® with 10 feeders, which individual recorded bunk attendance (BA), frequency of visits (FV) and feed intake (FI). The first 28 days of test were for adaptation to diet and environment, and the subsequent 91 days were considered as experimental period. Experimental period was divided in three sub periods (28, 28 and 31 days, respectively). Data were analyzed by PROC MIXED (SAS Inst., Inc., Cary, NC), including in the model period effects (adaptation - 1 and experimental periods - 2, 3 or 4) and animal age as linear covariate. During the adaptation period, low values (P<0.05) were observed of FI, BA and FV (991 ± 40.7 kg/day, 854 ± 33.2 min/day and 1172 ± 49.4 visits/day, respectively) in relation experimental period (1091 ± 18.5 kg/day, 965 ± 15.1 min/day and 1217 ± 22.5 visits/day, respectively). Feeding behavior traits were analyzed in four test periods (Figure 1), and a reduction (P<0.05) in FI (from 1162 ± 39.2 to 984 ± 77.6 kg/day) and BA (from 992 ± 32.1 to 866 ± 63.6 min/day) was observed in the third period. Additionally, FV means increased from the first to the fourth period (from 1036 ± 95.9 to 1328 ± 92.5, respectively). The variation was higher in the adaptation period and in the fourth period for all studied feeding behavior traits. Feed intake and behavior patterns were different for adaptation period when compared to the other test periods. Environment effects can influence feed intake and behavior in any period of the test. Complementary researches are necessary in order to elucidate the causes of variation in feed efficiency tests.