Efeito do Tempo de Ensilagem sobre a composição química, perfil Fermentativo e Estabilidade Aeróbia de Silagens de Milho (Zea mays)

Abstract

Corn silage is widely used due to its nutritional quality, dry matter production per ha-1 and good fermentative standard. The objective of this study was to evaluate the effect of silage time on fermentation pattern, nutritional quality, losses and aerobic stability of corn (Zea mays) silages. A completely randomized experimental design was used, with four treatments (0; 12; 24 and 48h for ensilage after forage cutting) and five replications. After 30 days of fermentation, losses by effluents, losses by gases and recovery of dry matter were determined. For the stability test, approximately 2kg of silage was removed from each experimental unit and added in 4 liter plastic containers, measured at temperature (2 hours interval), pH and electrical conductivity (6 hours interval). the determination of ammonia nitrogen, buffering capacity and carbon dioxide. Chemical composition was evaluated for dry matter, mineral matter, ether extract, crude protein, organic matter, neutral detergent fiber and acid, total carbohydrates, non-fibrous carbohydrates, neutral detergent insoluble protein and hemicellulose. All results underwent regression testing at 5% probability. The ensiling period did not influence the fermentative losses for gas losses and dry matter recovery. The chemical standard of silage had no change for crude protein content with averages of 84.60g; 78.26g; 82.58g and 74.22g, respectively for treatments 0h; 12pm; 24h and 48h. Silage time after cutting alters carbon production dynamics, increases ammonia nitrogen content, reduces buffering capacity and decreases silage stability.