Application of the law of diminishing returns to describing the relationship between metabolizable energy intake and growth rate in broilers

A monomolecular equation was constructed and seven published data sets were used to evaluate it with regard to its ability to describe the relationship between metabolizable energy intake and growth rate in broilers.The monomolecular takes the form:where G is liveweight gain (g/g of LW/d), / is metabolizable energy intake (kJ/g of LW/d), and G M , K and / are growth parameters.This equation was used with non-linear regression to estimate the parameters and combine them to determine other biological indicators.The estimates of metabolizable energy requirement for maintenance varied between 457-655 (kJ/kg of LW/d), depending on the data set.Predictions of average metabolizable energy requirement to produce 1 g of liveweight gain varied from 9 to 13 kJ (2.2-3.08 kcal).These results show good agreement with previous studies.The present study demonstrates that the monomolecular equation is suitable for using as a simple inputoutput device relating metabolizable energy intake to growth rate in broilers.