title: Endogenous N-excretion and minimal protein requirement for maintenance of the common marmoset (Callithrix jacchus).
abstract: The protein requirement for maintenance of the marmoset Callithrix jacchus was investigated by factorial calculation via the N balance technique. Six adult male marmosets were fed a protein-free pelleted diet for 22 days. When a low protein diet (6%) was fed in the preperiod, only 7 days were necessary and when fed a higher protein diet (18%) 10 days were necessary to reach a minimum of N excretion during protein depletion. Body weight losses averaged 11% and food intake was 21% lower in the protein free period. The average endogenous urine N (EUN) was 62.1 mg N and endogenous fecal N (EFN) 49.2 mg N/kg W0.75. Body surface losses (BSN) were assumed to be 20 mg N/kg W0.75. The total endogenous loss of 131.3 mg N/kg W0.75 is similar to that of other species. Net protein utilization (NPU) of well balanced proteins, determined near the N equilibrium, was 51.8%. The calculated net protein requirement amounts to 313.6 mg N/kg W0.75, which corresponds to a dietary protein content of 6% in a diet of high caloric density, (about 19-20 MJ/kg dry matter) when the food intake is 3.3% of body weight.
mesh_terms: D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D000830:Animals, Laboratory / Q000378:metabolism*; D001835:Body Weight; D002144:Callithrix / Q000378:metabolism*; D002143:Callitrichinae / Q000378:metabolism*; D003404:Creatinine / Q000652:urine; D004044:Dietary Proteins / Q000008:administration & dosage*; D008297:Male; D009584:Nitrogen / Q000378:metabolism; D009751:Nutritional Requirements
chemical_list: D004044:Dietary Proteins; D003404:Creatinine; D009584:Nitrogen