Losses of Energy and Nitrogen in Drying Excreta of Hens

IN ENERGY and nitrogen balance studies, which are two of the main criteria of the nutritive value of a poultry feed, errors may result from losses of energy and nitrogen from excreta due to drying. These losses can be avoided by determining the energy and nitrogen in fresh instead of dry samples of excreta. A highly significant loss of energy and nitrogen due to drying of cattle feces was reported by Kleiber et al. (1936) and Colovos et al. (1957). Such a loss has not been established for chicken excreta. In research with poultry to determine the nutritive value of feedstuffs, gross energy usually is determined by burning dried excreta in a bomb calorimeter. Protein generally is determined on dried samples by the Kjeldahl method. Excreta samples obtained from 24 White Leghorn hens were used in this study to determine the possible loss of energy and nitrogen due to…