In vivo body composition studies in rats: assessment of total body protein

The precision and accuracy of a prompt-gamma neutron activation facility developed to assess total body protein in rats is estimated. The coefficient of variation of nitrogen measurement, as estimated by repeated measurements on 15 rats, was 5.5% for an equivalent dose of 60 mSv (Q = 20). Good agreement was observed in comparing the results of in vivo neutron activation analysis and chemical carcass analysis performed by the Kjeldahl method. The application of the technique in comparing the effect of a low-fat and a high-fat diet on body protein in rats is demonstrated.