Abstract
As simplified methods of measuring rumen ammonium nitrogen (R-NI-13-N), we used the reagent for blood ammonia (NH3-kit), the reagent for serum urea nitrogen (BUN-kit), and the reagent for dry-type blood autoanalyzer (Drychem). The compared measurements made with them and those made with the conventional steam-distillation method. Even when operation error of the sample dilution was included, the coefficient of variance for the Drychem R-NH3-N measurement was 2.86%. This constitutes adequate reproducibility. A significant (P<0.001) correlation (r=0.978) was observed between Drychem and steam-distillation R-NI-13-N measurements. Moreover, the two sets of values approximated each other. Significant (P<0.001) correlation was observed between R-NE13-N measurements obtained with steam-distillation and Drychem R-NE13-N and BUN-kit (r=0.991) and NH3-kit (r=0.961) R-NH3-N measurements. But values obtained with NH3-kit were more than 2 times higher than those obtained with Drychem. From these results, we conclude that Drychem and BUN-kit are practical and useful simplified methods of measuring R-NH3-N.
