Critical examination of the methods employed in silage analysis, with observations on some special chemical characteristics of “sour” silage

Abstract

A résumé of the analytical methods hitherto employed for the chemical investigation of samples of silage has been given. It has been shown that these methods fail to yield trustworthy results when applied to the analysis of “sour” silage, owing to the disturbing effect of the presence of appreciable amounts of ammonium salts of organic acids in this type of silage. Investigations have been made into the behaviour of the ammonium salts of acetic, butyric and lactic acids, when solutions of these substances, in the presence and absence of the free organic acids, are (1) submitted to distillation in steam, (2) evaporated in the steam oven under conditions comparable with those obtaining during the determination of the dry matter of silage. The bearing of these results on the problem of silage analysis has been discussed. A modified analytical procedure for silage investigations has been devised which is capable of general application.