Comparison of diet evaluation systems for cattle in an intensive beef production model. II - Creep-feeding

Twenty-nine suckling Canchim calves averaged 107 kg of body weight and 55 days of age were fed with supplement during the wet season, in order to evaluate the performance provided by nutritional adjustments recommended by different systems of evaluation of diets. Supplements were composed of grounded corn grain, cottonseed meal and soybean meal, in agreement with the recommendations of the Metabolizable Protein System (MP); Cornell Net Carbohydrate and Protein System (CNCPS); and Intestine Digestible Protein System (PDT), for the highest possible body weight gain, according to indications of each adjustment system. The daily body weight gain obtained did not differ among treatments CNCPS, MP and PDT, with mean of 1.0 kg/head for each treatment studied. The body weight differences at weaning, in relation to a control group without supplementation were estimated, so that the creep-feeding would provide monthly net profit of 0, 0.6, 1.2, and 6%, and values of 15.5, 27.1, 17.1, and 15.9 were observed for the CNCPS; 27.9, 17.6, 16.4, and 28.7 for the MP; 18.1, 20.4, 35.6, and 22.5 kg body weight/head for the PDT system. It was concluded that the evaluated supplements provided results compatible with the estimated animal performance.