The utilization of roughage by sheep and the red kangaroo, Macropus rufus (Desmarest)

Abstract

Two roughage diets, lucerne hay and oat straw, were given to three Corriedale sheep and three red kangaroos. Dry matter intakes, nitrogen balances, and body weight changes of the animals were compared, and the digestibilities of each diet by each species and the retention times of the food residues in their alimentary tracts were estimated.

The kangaroos were less affected by the quality of the diet than were the sheep. The sheep ate nearly the same amount of lucerne hay and less oat straw than the kangaroos, after adjustment for body weight differences. Digestibility coefficients were higher for the lucerne hay when fed to the sheep, but apparent dry matter digestibility coefficients for oat straw were about the same for sheep and kangaroos. The mean retention times of food residues were lower in the kangaroos, and dietary nitrogen was retained to the same or a slightly lesser extent than in the sheep. The kangaroos maintained weight on the poor quality diet and appeared to be even better adapted to utilize this type of roughage than the sheep.