Avaliação de silagens mistas de capim elefante com sorgo forrageiro

Abstract

The elephant grass stands out among the other used for silage due to high productivity and higher chemical characteristics than the others, having higher soluble carbohydrate content. However, has characteristics that limit the production of silage fermentation profile with suitable, such as high humidity and high buffering capacity. In contrast, the sorghum is a crop for silage indicated by presenting good production and nutritional characteristics. The high content of soluble carbohydrates can trigger undesirable fermentations, increasing losses by changing the nutritional composition and stability of silages when exposed to air. The objective of this research was to evaluate the effects of different proportions of inclusion of sorghum in elephant grass silage on losses, the fermentation profile and aerobic stability of silage. The experiment was carried out in the Forage Section of the Federal University of Paraíba. The design used for the experiments was completely at random, composed of five treatments with four replications. The experiment was carried out in the Forage Section of the Federal University of Paraíba. The design used for the experiments was completely at random, composed of five treatments with four replications. The treatments were represented by different proportions of sorghum in grass silages: 0% (only grass); 25% (25% sorghum + 75% grass); 50% (50% sorghum + 50% grass); 75% (75% sorghum + 25% grass) and 100% (only sorghum), the natural material. They were divided into two experiments. For the first experiment, we used 20 silos for assessing losses of silage fermentation and chemical composition of the silage at the opening of the silos and after 48 hours of exposure to air. For the second experiment, another 20 silos were used; these were completely filled by the material to be ensiled for estimating the total losses during fermentation, and after 48 hours of opening. It was observed effect fermentation period over 30 days and periods of 24 and 48 hours after opening of the silo for enterobacteria, molds, yeasts and lactic acid bacteria. The variables were affected by the inclusion of sorghum proportions in grass silages. After analyzing the results it is believed that when the grass silages are added sorghum silage may improve its qualities. Realize a better performance in the fermentation profile, qualitative characteristics and microbiological profile was to include 50% of the sorghum silages showed satisfactory performance. The inclusion of 50% of sorghum silage promoted improvement in the nutritional value of sorghum silage and reducing nutrient losses in silage.