Nutritional and fermentative quality of sugarcane (Saccharum officinarum) top ensiled with or without urea and molasses

摘要

This study was conducted to evaluate the effect of urea and molasses addition on physical properties, pH, temperature, dry matter loss and chemical composition of sugarcane top (SCT) silage. Treatments were arranged as 2*4 factorial, with two SCT types (green and burnt) and four silage treatment types (without additive, 4% molasses, 1% urea and 1% urea + 4% molasses) in a completely randomized design. Forages were chopped into 2 to 3 cm, treated with the additives and ensiled in 1.09 L mini silos for 45 days. The best average score values for smell, color, texture, mold appearance and pH was noted in silages made without additive or with molasses. The desirable pH (3.7 to 5.0) was obtained in all silages, except in green SCT ensiled with urea-based additives, while lower (P0.05) with molasses alone. Fiber fractions (NDF, ADF and ADL) of burnt SCT were not affected (P>0.05) by additives, while NDF increased with urea based additives and ADF decreased with molasses based additives in green SCT silage. The highest (P<0.0001) in vitro dry matter digestibility (53.68%), organic matter digestibility (48.34%) and metabolizable energy (7.74 MJ/kg DM) content were observed contained in burnt SCT silage treated with urea-molasses mix, whereas a significant reduction (P<0.0001) in non-fiber carbohydrate content was observed in green SCT ensiled with urea (8.4%) and urea + molasses (1.65%). In conclusion, both burnt and green SCT can be adequately fermented and preserved as silage without additive; however silage nutritive value, particularly of burnt SCT can be further enhanced by ensiling with urea and molasses.