Abstract
An experiment was conducted to study the possibility of using marker concentration in faeces to estimate rumen outflow of Cr-treated protein supplements and the liquid phase (PEG). There were no significant differences in the outflow of each marker from the rumen when determined directly from rumen or indirectly from faeces, suggesting that faeces could be used to measure the outflow from the rumen without the need for surgical preparation of the animals. The outflow rate of the liquid phase was considerably faster than Cr-treated protein supplements.