A Model of Animals Phenotype with Superior Growth

The aim of this study is to model and analyse a dynamic of feed conversion coefficient in pigs' ontogeny. Feed conversion is a process that couples feed intake, and growth. While there has been much research into the problem, a quantitative relation between the traits has not been revealed. The study considers feed as nutrient weight rather than its energy or a separate feedstuff. A main task of the research is to find out an analytical function between the traits. It is expected that the study will provide a new insight into the problem.

Animals are open systems; they need feed to sustain life, to grow and develop. It is plausible to suppose that growth of animal is a function of feed conversion and body weight. To find out and analyse this function a deterministic model of growth was built. The model was built as a dynamic system that describes the growth of individual animals. Both continuum and discrete-time modelling techniques are employed. The model is based on a data set obtained in experiments and field observations. Theoretical notions about the growth have been used for the model analyses.

It is shown that in ontogeny feed conversion and growth rate are functionally related traits. Between the traits, there is a nonlinear relation that concerns the growth rate, and feed conversion coefficient. In the model, the feed conversion coefficient is the variable that determines the dynamic of growth.