Chemical composition and degradability kinetics of conventional corn and brown mid-rib sorghum silage

Abstract

The chemical composition, dry mater and neutral detergent fiber digestibility and fermentation kinetics of the “33J56” and “Virgi” corn hybrids, and “Silo miel” and “Gigante verde” brown midrib sorghum varieties were compared. The corn hybrids were harvested at half milk line and sorghum varieties in soft dough stage, were ensiled in laboratory silos (n=3). After 45 d of fermentation, the laboratory silos were opened and analyzed for pH, DM, OM, ash, CP, EE, NDF, ADF, ADL, ME, IVDMD, IVNDFD and fermentation kinetics. No differences (P > 0,05) were observed in chemical composition between forage sources, except in NDF and ADF content, both were low (P < 0,05) in corn silage. GP at 72 h of incubation, fermentation parameters (A y C), fractional rate
of degradation (R), time at which R is maximal (tRM) were similar (P > 0,05) between forage sources. The fermentation parameter B was different (P < 0,05) between forage sources and between corn hybrids.