采用化学分析、活体外人工瘤胃产气量法和两步法,研究氢氧化钙处理(0、2%、4%、6%和8%(占干物质质量分数,下同))对甘蔗渣化学成分和活体外发酵参数的影响,确定提高营养价值幅度最大时的添加剂量。结果表明:随氢氧化钙添加水平的提高,甘蔗渣干物质中中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)和木质素含量呈二次曲线规律显著降低(P〈0.05),到8%添加量时,3者分别减少了23、5和7个百分点。钙和粗灰分含量呈二次曲线规律显著提高(P〈0.05);同时,DM、NDF消化率、96h产气量和总挥发酸(VFA)产量也显著增加(P〈0.05),DM和NDF消化率都达到了60%。综合数学模型求导得出表试验结论:氢氧化钙添加水平在5.1%~6.5%范围内提高甘蔗渣干物质和细胞壁消化率的幅度最大。最为有效地提高了发酵程度。
This study was conducted to examine the nutritional value of sugar cane bagasse fibers treated with calcium hydroxide (CH) and ensure the economical addition level based on measurements of changes in chemical components, gas production and two stage technique in vitro. Bagasse was treated with calcium hydroxide at 5 addition levels (0, 2%, 4%, 6%, and 8% of dry materials). As CH addition level increased, bagasse had quadraticly increased contents of calcium and ash (P〈0.05), but quadraticly decreased contents of NDF, ADF and lignin (P〈0.05), and increased (P〈0.05) digestibilities of DM, NDF, potential gas production and total VFA production. At the calcium hydroxide dose of 8%, the contents of NDF, ADF and lignin decreased by 23%, 5% and 7% respectively, the digestibilities of DM and NDF got up to 60%. In conclusion, calcium hydroxide treatment can enhance the fermentation of sugar cane bagasse by rumen microorganisms, with the effective level of calcium hydroxide added at 5.1 to 6.5% of dry bagasse.