Effect on fecal output of various dietary nitrogen sources in pig-tailed monkeys (Macaca nemestrina) fed fiber-free, semisynthetic diets

Abstract

Fiber-free liquid diets containing isonitrogenous amounts of various dietary nitrogen sources were fed to five adult male pig-tailed monkeys (Macaca nemestrina) with a mean weight of approximately 10 kg. All liquid diets supplied 3.0 g N/DAY PER MONKEY AND MAINTAINED THE ANIMALS IN A POSTIVE NITROGEN BALANCE. Initial baseline fecal output data were obtained by feeding the animals a commercial solid monkey chow. The dietary nitrogen sources fed were a) egg white protein, b) an enzymatic hydrolysate of fish protein supplemented with L-amino acids to simulate the egg albumin pattern, c) a mixture of pure L-amino acids simulating the egg pattern, d) a casein hydrolysate supplemented with amino acids, and e) an amino acid mixture with Rose's pattern. Total fecal matter, dry fecal matter, percent of moisture, fecal nitrogen, lipids and ash were determined for a 10-day period for each experimental diet. A very significant difference (P smaller than 0.001) was noted between each liquid diet and the solid chow, but no significant differences were found between the various fiber-free liquid diets, pointing to the effect of fiber as a major factor affecting fecal output. Monkeys fed liquid diets excreted fecal matter with a mean of 12.9 g/day, of which 4.7 g/day was dry feces (fecal dry matter 28.5%). Fecal nitrogen was found to be 0.25 g, fecal lipids were 0.19 g, and fecal ash was 0.59 g/day per monkey, respectively.