Aspectos fermentativos e perdas em silagem de soja aditivada com óleos essenciais

Abstract

This work aimed to evaluate whole soybean plant silages, with increasing levels of essential oils, in terms of microorganism count, fermentation losses and aerobic stability. For this, 25 minisilos were produced, with soybean silages with additives at concentrations of 0, 1,000, 1,500 and 2,000 and 2,500 mg of essential oils (blend of carvacrol - 75% and cinnamaldehyde - 25%) per kg-1 of mass of green forage, in a completely randomized design, with five replications of each treatment. After 120 days of ensiling, the silos were opened and the silages evaluated for microbiological profile, the losses of organic matter, dry matter, gases and effluents were calculated, as well as the dry matter recovery calculated. The aerobic stability of the silage was evaluated by monitoring the pH and temperature values. The count of total bacteria was higher in the control treatment, and followed a negative linear efect, according to the level of inclusion of essential oil in the silages. Negative linear efect was also verified in the lactic acid bacteria count. The aerobic bacteria count increased with the addition of essential oils to silage. However, levels above 1500 mg kg-1 reduced the total mold count. There was an interaction between treatments and silage exposure time, where higher levels of inclusion of essential oils reduced the temperature difference and kept the silage more stable over time. The inclusion of 1,000 and 1,500 mg kg-1 caused silages with higher pH, however, at the inclusion level of 2.500 mg kg-1 the pH values were the lowest, regardless of the time of exposure to air, in addition to losses by effluents be smaller. The inclusion of essential oils at higher concentrations is able to reduce the population of fungi and total bacteria, maintain lower pH values and more stable temperature, in addition to reducing effluent losses, ensuring better quality of the silage.