Abstract 176

Schlink,AC; Lindsay,-JA

CSIRO Division of Tropical Animal Science, Townsville, Qld 4814, Australia.

Proceedings-of-the-Australian-Society-of-Animal-Production. 1988, 17, 330-333; 11 ref.

Five crossbred zebu heifers fitted with permanent rumen cannulae were used in 2 experiments to evaluate molasses and raw sugar as energy supplements for cattle fed on Rhodes grass (Chloris gayana). In the first experiment the heifers were fed on Rhodes grass supplemented with: (1) 1 kg molasses; (2) 1 kg molasses and 95 g urea; (3) 1 kg molasses, 65 g urea and 200 g formaldehyde-treated cottonseed meal; (4) 400 g raw sugar, 90 g urea, 13 g (NH4)2SO4 and 5 g mineral mix; (5) 400 g raw sugar, 60 g urea, 13 g (NH4)2SO4, 5 g mineral mix and 200 g formaldehyde-treated cottonseed meal. Cattle given molasses and raw sugar supplements had similar roughage intakes, rates of DM disappearance and potential degradability of Rhodes grass as estimated by the nylon bag technique, mean retention time of CrEDTA and fluid flow, whereas rumen volume was significantly lower in cattle given raw sugar. The addition of a nitrogen source to molasses improved the rate of DM loss from nylon bags and decreased butyric acid production. In the second experiment, problems associated with the poor acceptability of raw sugar were overcome by addition of 20% molasses.