Desempenho de novilhas de diferentes grupos genéticos suplementadas durante a época da seca e transição seca/águas em pastagem

Abstract

Was evaluated the performance of heifers of different genetic groups supplemented with protein-energy-mineral supplement during the winter and transition winter to summer, grazing Brachiaria brizantha cultivate Marandu. Was used 96 heifers, with an average age of 223 ± 13 days and live weight (LW) of 182 ± 15 kg, 32 Guzera heifers (GA), 32 ½Guzera ½Nellore (GN) and 32 ½Red Angus ½Nellore (RAN). The 96 animals were supplemented during the experiment with two supplements with protein, mineral and energy composition, provided the amount of 1.5 kg per animal day. The first supplement containing 24% crude protein (CP) was provided in the first 84 days and the second supplement with 34% of CP was provided in the remaining 56 days. The experimental design was completely randomized, with 32 repetitions, the animal being considered an experimental plot and the three genetic groups as treatments. The data relating to animal performance were subjected to analysis of variance and the mean weight gain were compared using the Duncan test at 5% significance. The availability of total dry matter forage showed a mean value of 3.730,8 kg/ha. The average consumption volunteers supplementation was 1.011 kg (0.44% of LW) for RAN, 0.908 kg (0.47% of LW) for GN and 0,928 kg (0.47% of LW) for GA. Heifers RAN had higher final LW (P <0.05) when compared to other genetic groups, 260,81 kg, 215,98 kg and 217,53 kg for RAN, GN and GA, respectively. Average daily gain was greater for heifers RAN (0,473 kg/animal/day), followed by heifers GN (0,312 kg/animal/day) and GA (0,273 kg/animal/day) (P <0.05). Heifers RAN showed better weight gain followed by heifers GN and GA.