of phosphorus utilization in growing pigs Comparative evaluation of mathematical functions to describe growth and efficiency

ABSTRACT : Success of pig production depends on maximizing return over feed costs and 23 addressing potential nutrient pollution to the environment. Mathematical modeling has been 24 used to describe many important aspects of inputs and outputs of pork production. This study 25 was undertaken to compare 4 mathematical functions for best fit in describing specific datasets 26 on pig growth, and to compare these 4 functions for describing P utilization for growth in a 27 separate experiment. Two datasets with growth data were used to conduct growth analysis and 28 another dataset was used for P efficiency analysis. All datasets were constructed from 29 independent trials that measured BW, age, and intake. Four growth functions representing 30 diminishing returns (monomolecular), sigmoidal with fixed point of inflection (Gompertz), 31 and sigmoidal with variable point of inflection (Richards and von Bertalanffy) were used. 32 Meta-analysis of data was conducted to identify the most appropriate functions for growth and