Endogenous urea as a nitrogen source for microorganisms of the rabbit digestive tract.

The total urea release, measured in the different secretions of the digestive tract of the rabbit, is estimated to be 22 mmol/day, which represents half of the urea produced by the nitrogen catabolism of the animal. This quantity represents a significant source of nitrogen for symbiotic bacteria and, due to coprophagy , could be recycled in the bacterial proteins digested by the rabbit.