The aim of this study was to evaluate 4 candidate
mathematical functions for best fit in describing specific
data sets on pig growth, and to evaluate these 4 functions
for describing of P utilization for growth in a separate
experiment. It was found that the nonlinear mixed analysis can give reliable parameter estimates and is a useful tool when analyzing data from multiple studies. Although the Gompertz equation has been used extensively, the Richards equation was superior in describing growth over time and is recommended for use in data analysis in nonruminant animals. Therefore, it is recommended that future studies on growth and nutrient intake analyses consider other models such as the monomolecular and flexible equations such as the Richards as well as the Gompertz.