Ensiled brewers' grains increased feed intake, digestibility and N retention in cattle fed ensiled cassava root, urea and rice straw with fresh cassava foliage or water spinach as main source of protein

The experiment was carried out to study effects of supplementary dietary protein of differing solubilities, and of brewers' grains on feed intake, digestibility and N balance in local 'Yellow' cattle fed ensiled cassava root, urea and rice straw as basal diet. Four local ('Yellow') male cattle were assigned to 4 treatments in a 4*4 Latin square arrangement: BG-CSF: brewers' grains with cassava foliage, BG-WS: brewers' grains with water spinach, NBG-CSF: no brewers' grains with cassava foliage, NBG-WS: no brewers' grains with water spinach. Experimental periods were of 15 days: 9 days for adaptation, 5 days for collection of feces and urine and the last day to take rumen fluid by stomach tube. Adding 5% of brewers' grains to the diet increased the DM intake, the apparent DM digestibility and N retention. Similar but smaller benefits were found when water spinach replaced cassava foliage as the main source of (true) protein.