Studies on marsupial nutrition. VI. The utilization of dietry urea by the Euro or Hill Kangaroo, Macropus robustus (Gould)

Abstract

Macropod marsupials, the kangaroos and wallabies, are characterized by a ruminant-like digestive physiology. One feature of digestion in eutherian species of ruminants is the ability of these animals to utilize non-protein nitrogen through the conversion of such nitrogen to microbial protein by the microorganisms in the rumen. In the present experiments with the euro or hill kangaroo (M. robustus), the utilization of dietary protein (casein) and non-protein nitrogen (urea) has been compared by means of nitrogen balance feeding trials. No consistent differences between the levels of nitrogen retention and urinary nitrogen excretion were observed for euros fed rations supplemented with either casein or urea. It is suggested that the digestion of nitrogen by the ruminant-like macropod marsupials is similar to that of eutherian species of ruminant herbivores.