In order to recommend corn hybrids for silage it is not enough to have high dry matter. It is also necessary that the silage presents high effective matter degradation (DEF) of the whole plant. This investigation had the objective of evaluating agronomic, bromatologic, and rumen degradability of dry matter of commercial corn hybrids, recommended for silage production, and also experimental hybrids from crosses of lines of high and low degradability. It was evaluated the performance of eighteen experimental hybrids and five commercial hybrids recommend for silage production. The experiment was established in 2003/2004 crop season in randomized block design with three replications. The experimental plot was constituted of four rows 5.0 meters long. Corn plants were harvested at 20 cm from soil level at milk line at half grain stage. The silages were incubated in situ for 0, 6, 12, 24 and 96 hours in the rumen of three fistulated cows. Effective degradability was calculated based on 0.05%/h of passage rate. It was observed that among cultivars there were hybrids, that present good potential for silage production with high effective matter degradation (DEF) of the whole plant, independently of grain texture. The strategy of synthesizing hybrids aiming at high dry matter effective degradability based on lines with high DEF is correct. The low correlation between effective degradability with a agronomic, and bromatologic characteristics indicate the need for better use of DEF in order to select corn hybrids of high quality of silage production.
Zea mays; degradability; rumen
