Effect of Formic Acid and Dried Steep Liquor Concentrate on Digestibility and Steer Growth from Corn Silage

The influence of adding 0.5% formic acid or 5% DSLC to corn forage at ensiling was studied in a series of digestion and rumen fermentation trials. Each of the three silages was fed to all animals as part of three complete rations. Ration 1 consisted of 87% silage+13% of a 30% protein equivalent liquid supplement; ration 2 consisted of 60% silage, 13% liquid supplement and 21% shelled corn; and, ration 3 consisted of 33% silage, 13% liquid supplement and 54% shelled corn. The two silage treatments significantly improved dry matter, crude protein, crude fiber and NFE digestibility. When rations were analyzed across silages, each increase in percentage of corn significantly (P<.01) increased the digestibility of dry matter, NFE and decreased the digestibility of crude fiber. A short feeding trial (40 days per ration) with growing Hereford steers indicated that steer growth reflected the differences in digestibility of the silages and rations.