Cane molasses (CM) a by-product of sugar production, provides a relatively cheap means of increasing the energy content of ruminant diets. It is commonly thought that dietary concentrations of CM above about 200g/kg of the dry matter (DM) intake will lead to a reduction in rumen pH and hence have a depressant effect on forage digestibility. Recent work in vivo at the FEU and in vitro (ref 1) has suggested that there is an interaction between forage and CM, and indeed the in vitro experiment found evidence that increasing the proportion of CM actually enhanced the digestibility of the mixture. A further experiment was therefore conducted to monitor rumen pH and measure the degradability of hay DM in sheep fed increasing levels of molasses.