Beef production from formic acid-treated and wilted silages

Abstract

SUMMARY1. Herbage was ensiled, fresh at 17% DM or wilted to 32% DM, with and without the addition of formic acid (19·2 kg/tonne DM). The silages were fed individually ad libitum to 36 fifteen-month-old British Friesian steers of about 280 kg initial live weight (nine animals per treatment).2. Wilting and the application of formic acid both inhibited fermentation, resulting in silages with higher levels of water-soluble carbohydrates, lower concentrations of volatile nitrogen and lower organic acid contents.3. There were no significant dry matter × formic acid interactions in dry-matter intake or daily live-weight gain.4. Treatment with formic acid did not enhance significantly either dry-matter intake or daily live-weight gain. Furthermore, it had little effect on digestibility, nitrogen retention or metabolizable energy (ME) concentration.5. Wilting before ensiling increased dry-matter intake from 5·0 to 8·3 kg/head per day with consequent marked increases in ME intake, nitrogen retention and live-weight gain. Wilting, however, had little effect on digestibility, ME concentration, or the efficiency with which dietary nitrogen intake was retained.