Nitrogen, calcium and phosphorus utilization from commercial diet in dogs

Abstract

After looking over the literature concerning the nitrogen, calcium and phosphorus retention, in various animal species, balance studies were made in dogs using a commercial ration (Dog meal). It was found that 31.3% protein, and nutritive ratio 1:2.9 (Andreasi, 1956) were satisfactory for the growth maintenance requirements of the dogs studied. Both, adults — about two years old — and young — sixteen weeks old — presented nitrogen positive balance. The differences between ages were significant. However, concerning the calcium and phosphorus elements, the adults dogs could not set up positive balance in spite of the fact that they ingested sufficient amounts of both elements and in proper ratio as well. The intake amounts of 331 mg/kg of calcium and 223 mg/kg of phosphorus in adults, daily, determined —23.2% for the calcium and —24.6% for the phosphorus or, in other words, they presented negative balances. On the other hand, the young dogs showed higher hability to draw from the ration, the mineral elements necessary to set up positive balance. The young dogs, on the average, ingested 457 mg/kg of calcium and 308 mg/kg of phosphorus, daily, and presented positive balance of about 13.5% for calcium and 7.2% for phosphorus.