EVALUATION OF BARLEY SILAGE HARVESTED AT BOOT AND SOFT DOUGH STAGES

Barley (Hordeum vulgare, L.) harvested at boot (may 7, 1988) and soft dough (June 6, 1988) stages of maturity was ensiled for nutritive comparisons. Boot stage was wilted, and soft dough was direct-cut at 15 (low) and 25 cm (high) above ground. Yields were 3690, 8750, and 6287 kg DM/ha for boot, soft dough-low, and soft dough-high, respectively. Apparent digestibilities of DM, CP, and ADF were 74.7, 75.4, and 70.8% for boot; 61.9, 50.5, and 44.7% for soft dough-low; and 62.3, 47.2, and 49.7% for soft dough-high, respectively, when fed to heifers. The TDN was 71.2, 62.0, and 62.8% of DM for boot, soft dough-low, and soft dough-high, respectively. Thirty-six lactating Holstein cows were fed silages to supply 75 or 60% of diet DM for 60 d. Milk yields were greater for high-vs. low concentrate diets and averaged 28.3 vs. 25.7 kg/d for boot, 26.3 vs. 24.8 kg/d for soft dough-low, and 26.9 vs. 25.7 kg/d for soft dough-high, respectively. No differences among diets were significant for DM intake or 4% FCM. Even through apparent digestibilities of DM, CP, and ADF were greater for boot stage silage, milk production was not significantly affected by stage of maturity at harvest under summer conditions.