Methoxyl as an Indicator of the Nutritive Value of Forage

Abstract

The relationships between forage digestibility and forage methoxyl and between forage digestibility and fecal methoxyl were investigated. Three forage mixtures of different botanical composition and several stages of maturity were studied. Digestion coefficients for the forages were determined for clipped forages by conventional digestion trials and for grazed forage by the chromogen technique. There was a highly significant negative correlation (r = -.826) between dry matter digestibility and the methoxyl content of the forages. The regression of dry matter digestibility (%), Y, on forage methoxyl (%), X, was Y = 91.01 - 13.968X. The regressions of dry matter digestibility (%), Y, on fecal methoxyl (%), X, also were calculated. For the 3 forages hand-fed and grazed, it was possible to pool regression data. The equation relating dry matter digestibility (%), Y, to fecal methoxyl (%), X, was Y = 94.176 - 9.586X. The correlation coefficient for 107 observations between dry matter digestibility and fecal methoxyl was -.742.