Abstract
Convienient method for estimating TDN and DCP contents in ammoniated hay was examined in this report. Feed organic matter was divided into following three fractions; organic cellular contents (OCC), organic 'a' fraction in cell wall (Oa; organic matter digested by cellulase) and organic 'b' fraction in cell wall (Ob; residual organic matter after cellulase digestion) by successive treatments with actinase and cellulase. Regression equations between in vivo TDN (with sheep) and some fractions mentioned above were caluculated to estimate TDN and DCP contents. Better estimations were obtained with using various fractions determined by enzymatic analysis. TDN content was estimated from OCC+Oa fraction with the highest appliciability as shown in the following quadratic regression equation; Y=16.651+1.494X-0.012X^2 (R^2=0.951, Se=1.184), where Y=TDN content in % dry matter and X=organic cellular content (OCC)+high digestible fiber (Oa). DCP content was estimated with the best result from crude protein content as shown in following linear regression equation; Y=-2.100+0.684X (R^2=0.949, Se=0.708) where Y=DCP content % dry matter and X=crude protein content.
