Qualitative parameters of sugarcane silages treated with urea and calcium oxide Parâmetros qualitativos de silagens de cana-de-açúcar tratadas com ureia e óxido de cálcio

The objective was to evaluate the fermentation parameters, chemical composition and fractionation of carbohydrates of sugarcane silages treated with urea and calcium oxide (CaO). Upon ensiling, the treatments applied to the sugarcane were: 1% urea; 0.5% urea + 0.5% CaO; and 1% CaO, in relation to a control silage, without additive. The chemical additives (urea and CaO) were added at ensiling, in an amount calculated based on the fresh matter (as is). A completely randomized design consisting of four treatments (silages) and nine replicates was adopted. The material was conditioned in PVC mini-silos for five months. At the end of the storage period, silos were weighed again and samples were collected to quantify the losses caused by fermentation, dry matter recovery, pH, and ammonia nitrogen (N-NH 3 ) of the silages and to evaluate the chemical composition and fractionation of carbohydrates. The silage with 1% CaO showed the highest recovery of dry matter, and in terms of carbohydrate fractionation, it showed the highest levels of soluble and potentially soluble carbohydrates. Addition of 1% CaO during