A general compartmental model for interpreting gas production profiles

Equations to describe gas production profiles, obtained using manual or automated systems for in vitro fermentation of ruminant feeds, are derived from first principles using a general compartmental model. The underlying pools represented are the potentially degradable and undegradable feed fractions, and accumulated gases. Equations derived and investigated mathematically include a Gompertz equation. They were obtained by allowing the fractional rate of degradation to vary with time. The equations permit the extent of ruminal degradation, and hence the supply of microbial protein to the duodenum, to be evaluated thereby linking the gas production technique to animal production.