Efeitos da exposição aeróbia e tempo de armazenamento em silagens de milho realocadas.

Abstract

Some farms do not have the equipment to produce their own silage and thus are forced to purchase previously ensiled forage for use on their farms. In this process, silage is often moved to a new bunker silo on a different farm which exposes the forage mass to air. When exposed to air, silages have the propensity to spoil resulting in reduced nutritive value. In this context, it is important to study what happens to this silage after its relocation to new silos. The objective of this study was to determine the effects of relocation time (RT; Experiment 1) and storage time (ST; Experiment 2) on the fungi population, fermentative characteristics, aerobic stability, and chemical composition of corn silage. In Experiment 1, com silage was stored for 30 days and exposed to increasing periods oftime exposed to air (relocation times) before ensiling again for 30 days. Thirty experimental silos were used in a completely randomized design with three replicates per treatment. In Experiment 2, after 150 days of ensiling, silage was removed firom a bunker silo exposed to air for 9 h and relocated to experimental silos and stored thereafter for periods ranging firom 0 to 128 days. Twenty-seven experimental silos were used in a completely randomized design, with four replicates per treatment. Exposure of corn silage to air during relocation for up to 60 h followed by 30 days of storage, did not compromise the fermentation profile nor the nutritive value of the silage. The losses of dry matter (DM) and non-fiber carbohydrates (NEC) increased in corn silage stored for periods longer than 32 days after relocation. Relocated silages showed greater aerobic stability when exposed to the air during relocation and this was more pronounced, during prolonged storage periods. The quality of relocated silage depends mainly on its composition at the time of relocation. The results of the present study show that the storage period has more impact on nutrient losses in relocated silage than the relocation period does.