Composição corporal e exigências de macrominerais para ganho de peso de caprinos em pastejo

An experiment was conducted to estimate the body composition and nutritional requirements of macrominerals for the weight gain of ½ Boer and ½ mixedbreed kid goats, in the phase of growth on pasture in the semi-arid region. The experiment was developed at ‘Nupeárido’ farm, in Patos, Paraíba State. Twenty-four kids were used, with average initial body weight of 15 kg, distributed into four treatments with increasing levels of concentrate supplementation (0, 0.5, 1.0 and 1.5% of body weight). The animals, maintained under semi-confinement system, received feeding supplementation in individual stalls when they were gathered daily. When one of the animals of each group reached 30kg of body weight, all other animals in the group were slaughtered after a 16-hour fast. Body composition varied from 15.36 to 17.17 g of Ca; 8.16 to 8.24 g of P; 1.00 to 1.42 g of Na, and 1.23 g of K per kg of empty body weight. The net requirements of Ca, P and Na varied, respectively, from 13.96 to 15.61 mg, 6.55 to 6.62 mg and 1.16 to 1.65 mg, and is of 0.98 mg of K by gram of weight gain for animals between 15 and 30 kg of body weight.