Mathematical modelling of nitrogen flow in growing pigs and lactating sows

The present paper describes both nutrient-partitioning and metabolic models as applied to pigs. It is suggested that nutrient-partitioning models are most useful for use as management aids for commercial pork production, but that metabolic models may be more useful in understanding biological mechanisms. There is a pressing need for more quantitative information on potential protein deposition rates, the relationship between protein deposition and energy intake, endogenous amino acid losses, and metabolic effects on reproduction, all under varying conditions of genetic strain, health, ambient temperature, stocking density, and other factors.