Laboratory ensilage of Setaria sphacelata cv. Nandi and Chloris gayana cv. Pioneer at a range of dry matter contents

Abstract

Regrowths of Setaria sphacelata CV. Nandi and of Chloris gayana CV. Pioneer were wilted for various periods before laboratory ensilage. Dry matter contents at ensiling were from 17 to 42 per cent in the Nandi setaria and from 22 to 68 per cent in the Rhodes grass. The unwilted silages were unstable during storage, but decomposition was not extensive, and losses of dry matter and nitrogen were not heavy. Wilting to dry matter contents of near 40 per cent and above stable silage with very small losses of dry matter and nitrogen. Milder wilting to dry matter contents of 30-35 per cent did not produce stable silage. The water activity of the plant material fell during wilting and during the early stages of ensilage. Levels in the wilted silages were low enough to prevent the production of butyric acid, and in the heavily wilted silage to also retard production of lactic acid. Contents of acetic acid and volatile bases fell as the dry matter contents at ensiling increased. The laboratory silos were air-tight. The results of this experiment would therefore not apply in practice unless air was excluded from the silage.