Go with your gut: Digestibility and digestive function of two arid-zone Australian murids, Pseudomys australis and Notomys alexis

Spinifex hopping-mice (Notomys alexis) and plains mice (Pseudomys australis) are able to successfully occupy arid zones of Australia. We studied the digestive parameters and energy assimilation of captive spinifex hopping-mice and plains mice. The experiment consisted of six diets fed to the animals for periods of 12 days per food type. On a dry matter basis, the plains mice consumed between 2.5 and 7.2% and the hopping-mice between 5.8 and 9.3% of their body mass in food per day. The body mass of the spinifex hopping-mice increased significantly on the sunflower seed diet, while body mass did not change significantly for the plains mice on any diet. Apparent digestibility of macronutrients was similar in the hopping-mice and plains mice when maintained on the same diet, however digestibility of total micronutrients differed. Maintenance energy requirements for the plains mice were 529 kJ kg−0.75 d−1 and spinifex hopping-mice 550 kJ kg−0.75 d−1. Spinifex hopping-mice and plains mice are able to exploit a range of food items and efficiently digest macronutrients, to ensure they meet their nutritional needs, an ability they require in the variable arid environment. The information gained in this study increases the paucity of information on Australian native murids, specifically their digestive function and energy requirements, and will aid captive murid management. The study will allow future expansion into field studies, to aid the conservation of wild rodent diets and nutrition of arid zone murids.