The effect of formic acid with formalin addition and wilting on silage fermentation and intake, and on liveweight change of young cattle

Data from seven experiments conducted at ADAS Liscombe Centre during 1980-1983 were used to compare formic acid with formalin-treated unwilted (FF) and wilted silage (WFF) with wilted non-additive-treated (W) silage made from herbage [dry matter (DM) of 172 g/kg and water-soluble carbohydrate (WSC) 114 g/kg DM]. Following ensilage, the DM content of FF was significantly less than W and WFF. Compared with W, WFF treatment significantly decreased silage pH, ammonia-N and butyric-acid content and significantly increased the residual WSC, whereas FF significantly reduced pH, ammonia-N, butyric acid, protein and ash content and significantly increased lactic acid, acetic acid and lactic acid expressed as a proportion of total acid content. DM losses were significantly higher for FF than from W or WFF treatments. W and WFF significantly increased subsequent silage DM intake compared to FF. Daily liveweight gains were, however, significantly higher on FF compared with W but not WFF treatment. It is suggested that FF treatment of unwilted silage produced well-fermented silage, which when fed to growing cattle had a lower DM intake, but higher liveweight gain than wilted silage, and that when compared with wilted silage (W) formic acid with formalin treatment (WFF) improved fermentation, but provided no significant benefit in terms of either silage DM intake or liveweight gain. (C) 1998 Silsoe Research Institute.