THE EFFECTS OF FORAGE ON RUMEN FLUID VOLUME AND OUTFLOW IN CATTLE GIVEN MOLASSES BASED DIETS

Cattle appear to require a proportion of their feed intake on a molasses based diet to be in the form of roughage. It has been suggested that a major reason for this is that rumen fluid outflow rate decreases rapidly if the forage is not given when the molasses is the rain energy source in the diet. A comparison of rumen fluid volume and intake of cattle given a molasses based diet with I kg lucerne hay or oaten straw chaff or cotton lint were not markedly different but lucerne hay apparently promoted the fastest turnover with the smallest rumen fluid volume. Removal of the forage from the diet decreased rumen turnover rate only slightly. Key words: Cattle, molasses diet, roughage quality, rumen volume rumen fluid, outflow rate. The establishment of an efficient rumen function in cattle on sugar based diets is of major importance for efficient animal production. Where molasses is the basal diet, this means feeding a roughage with 'characteristics ' which maintain rumen fluid outflow high (Peron and Preston,1971; Rowe et al, 1979), In studies with cattle fed a basal diet of molasses it has been found that roughages vary in their ability to promote intake and utilisation of molasses. For instance, sugar cane tops added to