Efeito de adição amiloglucosidase e pepsina ao longo do tempo de ensilagem do milho grão moído e reidratado

Abstract

This study evaluated different ensilage days of ground and rehydrated corn grain, with or without addition of pepsin and amylase. The treatments obeyed a 2×2×5 factorial. The corn was divided in groups with amylase (A), pepsin (P), both (AP), and control (C), for 0, 15, 30, 60 and 90 days. The ground dry corn was moistened to 40% humidity and ensiled in experimental PVC silos. Electronic temperature recorders collected temperature in each silo every hour for 25 days. The silage average temperature was 21.6ºC and the maximum temperature was 33.2ºC. The addition of amylase (22.0ºC versus 21.2ºC, P <0.01) and pepsin (22.1ºC versus 21.0ºC, P <0.01) reduced silos internal temperature. Pepsin provided greater degradation of prolamines, and greater ruminal degradation when ensiled for 90 days, compared to not ensiled, an increase from 29.8 to 41.4%, 31.8 to 45, 3%, 45.1 to 63.2% and 69.8 to 86.1% (P <0.04) at times 3, 6, 12 and 24 hours of ruminal incubation respectively. Pepsin inoculation maximized the initial degradation of hydrophobic corn starch proteins. The 90-day silage time improved the ruminal degradation of dry matter. Pepsin improved the ruminal degradability of corn at all times and amylase did not affect it.