Analytical Expression for Formation of Indigestible Materials and Increase in Dry Matter Indigestibility with Growth of Some Tropical Grasses
Journal of the Faculty of Agriculture Kyushu University
This study was conducted to analyse the formation of indigestible materials and the increase in dry matter indigestibility with growth of some tropical grasses, using proposed formulae. Formulae for the formation of indigestible materials are, and where W = dry weight of forage, I = dry weight of indigestible materials, I, = amount of lignin, C = amount of cell wall constituents (CWC), (l/IV) -(tU/dt) = formation rate of I (FRI), (l/w) -(dLldt) = formation rate of I, (FRL), dI/dL = formation of
... I/dL = formation of I per unit increase in L (FIL), C/W = CWC ratio, (l/C)*(dLldt) = Specific FRL. Mean value over the interval t, to t2 for FRI, FRL, FIL, CWC ratio or Specific FRL was calculated -and designated as FRI , FRL, m, CWC or Specific FRL. A formula for the increase in dry matter indigestibility (DMI) is as follows, where RGR" =mean relative growth rate of forage, W,# W2, (1 -WJW,) =forage growth index -(FG index), (FRURGR, -f,lW,) = dry matter partition index into indigestible materials (DMP index). These formulae accounted for the differences in the formation of indigestible materials and those in the increase in dry matter indigest.ibility between species or between growth intervals for some tropical grasses. It, was suggested that proposed formulae were available for analyses of the formation of indigestible materials and the increase in dry matter indigestibility with growth of grasses.