METHOXYL ANALYSIS OF FEEDS AND FECES: A COMPARISON OF METHODS

Abstract

The Zeisel and hydrolytic methods for the determination of methoxyl were compared both for pure compounds and for forages together with the related feces collected during digestibility trials.The methods, which were both modified in some respects, showed comparable precision. On pure compounds the hydrolytic method gave results only 1 per cent lower than the Zeisel method but on feeds and feces it gave results 10–15 per cent lower. This discrepancy was shown to be due, in part, to the interference of N- and S-methyl groups.Highly significant correlations were obtained between the two methods and also between the dry-matter digestibilities and the methoxyl values obtained by either method. Reasons are given why the hydrolytic method is preferred when methoxyl is used as an indicator of digestibility.