Farelo de mamona detoxificado como aditivo proteico na ensilagem de cana-de-açúcar

Abstract

The aim of this study was to evaluate the influence of castor bean meal inclusion levels with two particle sizes on chemical composition, microbial populations, fermentation profile, losses during ensiling and aerobic stability of sugarcane silages. A completely randomized experimental design was used, in a 4x2x2 factorial scheme, with four levels of inclusion of castor bean meal based on natural matter (0, 5, 10 and 20%), two particle sizes (<0.5mm and >0, 5mm) and two opening times, 30 and 100 days, with four repetitions. The experimental silos contained Bunsen valves to quantify losses. The sugarcane was chopped at 2cm, followed by mixing with the castor bean meal. The material was compacted until reaching a density of 600 kg/m3. There was an increasing linear effect for crude protein on the inclusion levels of castor bean meal, in both granulometries and opening periods (P= 0.0001), with a mean of 21.36 and 19.54 g Kg-1 of DM. There was a quadratic effect for mold at the 100-day opening for the inclusion levels (P=0.0001), with an estimated minimum count at the inclusion level of 10.82%. An increasing linear effect was observed for the buffer capacity at the levels in the fine granulometry (P= 0.0196) of the 30-day opening. For the maximum temperature reached by the silo, there was a quadratic effect (P= 0.0011) for the inclusion levels, observing the lowest maximum temperature at the inclusion level of 13.69%. When using detoxified castor bean meal as a protein additive in sugarcane ensilage, it is recommended the 20% inclusion level for opening at 100 days, regardless of the particle size used.