甘蔗梢自然青贮过程中干物质含量和微生物数量的动态变化研究

Dynamics of Dry Matter Content and Microbial Counts During Natural Silage of Sugarcane Tops

为综合利用甘蔗稍,提高其利用率,以新鲜甘蔗梢为材料,采用称重和平板计数的方法,测定甘蔗梢自然青贮过程中干物质含量和微生物数量。研究结果表明:甘蔗梢青贮第7 d和第45 d干物质含量最低;随着青贮时间的延长,甘蔗梢青贮料的干物质回收率呈波浪变化趋势,但均在90%以上;同时,甘蔗梢青贮饲料的pH值也呈下降趋势,但整个青贮过程中pH值均在4.5以上,氨态氮含量也随青贮时间的延长而呈上升趋势。此外,青贮过程中,乳酸菌数量在第5 d才达到最大,而好氧细菌和酵母的数量第3 d最大。新鲜甘蔗梢自然青贮品质不佳,应选择合适的青贮添加剂,以便快速降低pH值减少氨态氮的产生。

In order to lay a data foundation for rational utilization of sugarcane tops,the dynamic changes of dry matter and microbial quantity during natural silage of sugarcane were monitored.In this study,fresh sugarcane tops were used as material to determine the dry matter content and microbial counts in the natural silage process of sugarcane by weighing and plate counting.The results showed that the dry matter contents of sugarcane tops silage on the 7th and 45th day were the lowest;with the extension of silage time,the dry matter recovery of sugarcane tops silage showed a wave change trend,and were all above 90%.At the same time,the pH of sugarcane tops silage also showed a decreasing trend,but the pH was above 4.5 during the whole silage process,and the yield of ammonia nitrogen also showed an increasing trend with the extension of silage time.In addition,the number of lactic acid bacteria reached the maximum on the 5th day of silage,while the number of aerobic bacteria and yeast reached the maximum on the 3rd day.Therefore,the quality of fresh sugarcane tops direct silage was not well,appropriate silage additives should be selected to the silage in order to rapidly reduce pH and the production of ammonia nitrogen.