Digestibilidade ruminal de silagem do milho grão moído e reidratado ensilados por diferentes tempos

Abstract

The objective was to evaluate the ruminal digestibility of ground and rehydrated corn grain ensiled for different times. There was no statistical difference for the evaluated starch data (P=0.80 for ensiling time effect). The ruminal pH was higher for corn without ensiling, considered ensiling time 0. Considering that the ensiling process produces lactic acid reducing the pH. There was an increase in the ammoniacal nitrogen content as a percentage of total nitrogen (N-NH3) and a reduction in the zein content as a percentage of dry matter as the days of ensilage increased. The increase in the N-NH3 content may be the result of a greater degradation of the zein protein in the ensiling process. With the reduction in the zein protein content, due to its proteolysis during the time that the corn was ensiled, there was an increase in the ruminal degradation of the dry matter of the corn incubated for 7 hours in the rumen. This increase was 63%, going from 56.9% of ruminal degradation for 7 hours, when the corn was not ensiled, to 92.8% when the corn was ensiled for 240 hours. It is observed that with 15 days of ensilage, there was already a 20,5% increase in ruminal degradation for 7 hours of incubation.