Effects of Coprophagy and Diet Quality on Two Microtine Rodents (Microtus pennsylvanicus and Microtus pinetorum)

The nutritional responses of meadow voles (Microtus pennsylvanicus) and pine voles (M. pinetorum) to prevention of coprophagy and to diets of different quality were examined. Food consumption, fecal production, diet digestibility, energy intake, body-mass dynamics, and frequency of fecal reingestion were measured. Differences in the measured variables were not identical for the two species, but prevention of coprophagy generally resulted in lower diet digestibility and a reduction of body mass. Increased food consumption by noncoprophagic meadow voles compensated for lowered diet digestibility resulting in similar rates of digestible-energy intake among all animals within each diet class. Although coprophagy may compete for intake (gut space and time), and feces provide less available energy per gram than either diet, coprophagy was of major importance for body-mass regulation of both species of voles. Apparently, feces can provide specific dietary nutrients in short supply in the diet.