Effect of preventing coprophagy in the rat on neutral detergent fiber digestibility and apparent calcium absorption.

The effect of coprophagy on apparent neutral detergent fiber (NDF) digestibility, and calcium absorption was evaluated by housing rats in four types of cages: regular, metabolic, and two anticoprophagy cages: a short linear tube cage which allowed the rat forward and backward movement of about one-half a body length and a long tube cage assembled to form a square which allowed the rat to move in one direction through the tube but not turn around. Three-day weight gains of animals in the regular or metabolism cages were greater than those of rats housed in either anticoprophagy cage. In contrast, average food intake did not differ among the four housing conditions. Wet, but not dry, fecal weights were greater in the two groups of rats in the anticoprophagy cages. Neither fecal NDF (% dry wt) nor apparent NDF digestibility was affected by housing conditions. Apparent calcium absorption was decreased by the anticoprophagy housing. The differences in body weight and apparent calcium absorption suggest that prevention of coprophagy in the rats produces significant changes in the efficiency of food and nutrient utilization. The failure to detect differences in NDF digestibility indicates that coprophagy has little impact on the study of fiber digestibility.