Published online by Cambridge University Press: 02 September 2010
Wafers made from dried ryegrass were fed to castrated male lambs in two experiments of 40 and 30 days' duration. In the first experiment, wafers of chopped feed were prepared which varied in unit density from 0·7 g/ml to 1·0 g/ml. In the second experiment, coarsely ground forage was passed through a ram press with a die of 5 cm diameter and the extruded material was then split into quarter and half wafers or left unsplit as whole wafers. Voluntary intake was measured throughout each experiment.
For the wafers with density of 1·0 g/ml the daily intake of organic matter was 75 g/kg LW0·75 as compared with 64 g/kg LW0·75 for the wafers with density of 0·7 g/ml but this difference was not significant. There was a significant (P < 0·05) interaction between wafer density and sub-period of the experiment. The daily intake of low-density wafers, expressed in g/kg LW0·75, increased throughout the experiment, whereas that of the higher density wafers did not change.
There was no overall effect of package size on organic matter intake, but the interaction between package size and sub-period of the experiment was significant (P · 0·001). The intake of the whole wafers was initially lower than that for the other treatments, but increased throughout the experiment, whereas the intake of the quarter and half wafers remained steady.