Effect of supplementation on the performance of F1 crossbred goats finished in native pasture

The present study aimed to assess the effect of supplementation on the performance of F1 (Boer × females of no defined breed) goats finished in native pasture. The experiment was conducted at the Universidade Federal de Campina Grande, Patos Campus, Paraíba, Brazil, with twenty-four 120-day-old non-castrated F1 (Boer × NDB) male goats, with a 15.52 kg live weight (LW). Animals were distributed in four levels of supplementation (0.0; 0.5; 1.0; 1.5% of body) and six replicates. In order to perform the evaluation of dry matter availability, the herbaceous vegetation was divided into grass and herbaceous dicotyledon and evaluated at the beginning (5/28/2007), in the middle (7/9/2007) and at the end (8/6/2007) of the experiment. In the beginning of the experiment, the availability of grass dry matter was 1,102.89 kg/ha, and at the end of the experiment, the availability of the referred matter was greater (1,494.81); on the other hand, the opposite occurred for the dicotyledons, with a dry matter content of 1,759.46 kg/ha in the beginning of the experiment, and only 236.76 kg/ha at the end of the experiment. Supplementation made it possible to estimate the increase in dry matter intake of 257.15 g/day and of 20.79 g/kg0.75/day, as well as the daily weight gain of 103 g for each percentage point increase that resulted from supplementation. The availability and nutritional quality of forage had a strong influence on the effect of supplementation on dry matter intake, with a negative response for supplementation levels of up to 0.74% of the live weight Consequently, the finishing of F1 crossbred goats in a grazing area in the Caatinga can be improved with the supplementation of concentrate at levels 1.0 to 1.5% of the live weight.