ABSTRACT The growing awareness of consumers regarding food safety, animal welfare and agricultural environmental impacts, simultaneously with the increase in food costs are facts that make the use of optimization of nutrition in production systems increasingly essential. Therefore, discrepancies between the diets formulated, offered and scraps by cattle must be minimal for this to be actually applied. With this, the objective of the present study has to evaluate the chemical composition and the physical composition of the formulated, offered and scraps diets in order to analyze the mixing precision and similarity of the feedlot diets of beef cattle. The study was carried out at the Experimental Farm Capim Branco and at the Laboratório de...