Nitrogen metabolism of four raw meat diets in domestic cats.

Little nutritional information has been collected from domestic cats fed raw meat diets. The objective of the present study was to evaluate differences in N metabolism of domestic cats fed raw beef-based diet (66 % crude protein (CP) and 20 % fat), bison-based diet (49 % CP and 39 % fat), elk-based diet (79 % CP and 6 % fat) and horse-based diet (60 % CP and 26 % fat). A total of eight intact adult female cats were fed to maintain body weight in a cross-over design. Daily food intake, faecal and urinary outputs, and N metabolism were measured. Dietary N was highly digestible (96.8 (SEM 0.7)) for all treatments. Urinary N accounted for a majority of total N excretion, and differences in total N excretion reflect differences in urinary N. Differences in N intake and N absorption were due to differences in CP levels among diets. N retention was similar to values reported in the literature for domestic cats fed purified and traditional extruded diets. Despite differences in protein concentrations and N intake, all raw meats tested maintained N metabolism.