Voluntary intake of maize stover supplemented by urea lick in dorper and local Malawi sheep.

Ten Dorper (16.0 to 37.0 kg) and Local (12.0 to 28.5kg) rams were used to determine the voluntary intake, digestibility, nitrogen retention of maize stover and live weight change. Dietary treatments were maize stover offered to meet the requirement for maintenance with urea lick, 1.5 or 2 times maintenance with urea lick. Stover stems had higher fibre content (78.5 % NDF) and lower content of nitrogen (0.34 %) and metabolizable energy than leaves. The sheep consumed leaves and rejected all stems. Intake of maize stover increased (P < 0.001) with increasing level of feed offered above maintenance. Sheep offered stover at 1.5 times maintenance had highest intake of stover (24.7 g/kg body weight) and nitrogen (1.5 % feed intake). There were no differences in intake between levels higher than maintenance. Digestibility was highest (P < 0.01) for sheep offered stover at 1.5 times maintenance. Higher nitrogen intake of stover diet increased digestibility and intake of dry matter owing to the stimulation of microbial activity. Liveweight gain was higher (P < 0.05) for sheep offered stover at 1.5 times maintenance (52 g/day) reflecting high intake, while sheep offered stover at maintenance lost weight (-105 g/day). Metabolizable energy intake increased with increasing total dry matter intake. Nitrogen balance was positive for diets with nitrogen intake of more than 1 % of feed intake. Nitrogen retention increased with high nitrogen intake. Breeds did not differ in voluntary intake. Dorper sheep had higher digestibility, higher nitrogen retention and gained more weight than local sheep (P < 0.001). It was concluded that for sheep fed low quality maize stover, voluntary intake, digestibility, nitrogen retention and liveweight gain increased by offering greater amounts of stover with high nitrogen intake (1 % feed intake). Differences in digestibility suggest that the Dorper breed could be a valuable resource for sheep production even in areas where low quality maize stover limit the use of European breeds.UNISWA Jnl of Agric Vol 8 1999: pp 44-4