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

Abstract

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.