The objective ofthis study was to propose and discuss a method to evaluate the efficiency offeed conversion into product from beef cattle based on regression techniques.The mathematical and statistical procedures were developed using a databasecomposed of measurements of dry matter intake and average daily gain of 380pure or crossbred zebu animals in 15 different experiments in the database fromthe BR-CORTE nutritional system. Two approaches were presented, based on linearand non-linear regression, with average daily gain and dry matter intake usedas independent and dependent variables, respectively. The feed utilization bythe animal was stratified into maintenance demand and real efficiency of conversioninto product. The maintenance demand presents similar interpretation in bothapproaches. When linear solution is considered, the real efficiency of productconversion is assumed to be steady and independent on average daily gain. Onthe other hand, when the non-linear solution is adopted, the real efficiencyof product conversion is assumed to be variable and dependent on gain. Alaikeinformation criterion was proposed to decide which model suits best. The evaluationof the efficiency of transformation of feed into product, in beef cattle, byregression techniques allows a broader understanding of system efficiency forit enables stratification of maintenance and production demands. Several inconvenientaspects concerning ratio indexes, such as food conversion ratio, are avoidedand the nutritional inferences become more accurate and precise.
