The digestiblity of two roughages and the rates of passages of their residues by the Red Kangaroo, Megaleia Rufa (Desmarest), and the merino sheep

Abstract

The digestibility of two roughages, lucerne chaff and oaten chaff, and the rates of passage of their residues through the digestive tracts of the red kangaroo, Megaleia rufa (Desmarest) and the Merino sheep were investigated. The dry matter intakes of kangaroos were from 55 to 58% of those of the sheep for diets fed ad libitum, but there was no difference between species in their abilities to digest apparent dry matter. The voluntary intake of oaten chaff was only about 60% of that of lucerne chaff by both species. The digestibility coefficients for apparent crude fibre in both diets were higher for sheep than for kangaroos. Sheep appeared to retain nitrogen more efficiently than kangaroos particularly when the intake of dietary nitrogen was at a low level. However, there appeared to be no difference between the abilities of both species to digest apparent crude protein. The mean retention times of food residues in the digestive tract were similar for both kangaroos and sheep when the animals were fed ad libitum. Sheep had appreciably greater mean retention times when comparisons were made at maintenance levels of feeding.