a1 The Grassland Research Institute, Hurley, Maidenhead, Berkshire SL6 5LR
1. A multicornpartmental model, which assumes first-order kinetics, is proposed to describe digesta flow along the gastrointestinal tract of ruminants.
2. Solution of the model yields a multiplicative equation, containing a single-exponential term and a double-exponential term, for describing faecal outflow rate.
3. The logarithmic transformation of the equation was fitted to eighty-two excretion curves obtained after the administration of marker into the rumen of cattle and sheep, and compared with other published models.
4. It was found to be superior to the other models in that it fitted all the data sets successfully.
(Received May 18 1984)
(Accepted December 31 1984)