Comparison of Methoxyl, Lignin, Crude Fiber, and Crude Protein Contents of Forage and Feces as Indirect Indicators of Dry Matter Digestibility

The correlation between methoxyl, lignin, and crude fiber contents of forage and feces and the digestible dry matter of the forage has been determined with 36 observations on forage samples and 65 observations on fecal samples (forage, --.818, +.300, and --.578, respectively; feces, --.851, --.087, and --.839, respectively).In subsequent work reported, the lignin determination was discontinued because it was not promising.The crude fiber determination was also discontinued, because it appeared to be no better as an indicator than the methoxyl determination, and the latter offered the technical advantages of measuring a precise chemical entity, and the procedure is less empirical.With a total of 66 forage and 98 fecal observations, correlation coefficients of --.724 and --.725, respectively, were obtained between methoxyl content and the digestible dry matter of the forage.The protein content of the feces was a less reliable indicator of digestible dry matter, whereas that of forage had no indicator value (correlation coefficients of .528and --.218, respectively).The quantity of methoxyl present in forage materials appears to be closely related to the lignin content of the forage (7, 13) and both are inversely related