青贮时间对香茅草营养成分的影响

Effect of Silage Time on Nutrient Contents of Cymbopogon citratus

【目的】探究青贮时间对香茅草营养成分的影响,旨在确定适宜的青贮发酵时间,为合理青贮及充分提高香茅饲用价值提供科学依据。【方法】采用感官评价和国家标准方法,对不同青贮时间香茅样品的感官品质和营养成分进行评价和测定。【结果】香茅青贮1月后,其蛋白质、粗纤维含量显著上升,达到峰值,蛋白质从青贮前的5.48%提高至6.64%,粗纤维从青贮前的34.96%上升至36.65%,青贮2~4月蛋白质较稳定,为6.32%~6.39%,随后明显下降,粗纤维在随后的2~6月较稳定,含量为34.23%~35.77%;钙含量在青贮前4个月变化不明显,第5、6月时有显著提高;磷含量在青贮前5月,先下降后缓慢上升,第6月时达到最高。香茅青贮至3个月时,感官评分等级为1级,氨基酸、粗脂肪和灰分含量均达到最大值,粗蛋白含量保持在较高水平。3月后青贮草料的感官评分等级为2级,其中粗蛋白、氨基酸、粗灰分和粗脂肪等营养成分逐渐降低,草料品质变差。【结论】香茅青贮的时间以1~3月为宜,青贮至3月时其营养成分达到最佳值。

【Objective】Effect of silage time on nutrient contents of Cymbopogon citratus was studied.【Method】Changes on the nutrients in C.citratus during silage was monitored periodically to determine the optimal fermentation period for cattle feeding.【Result】After one month of silage,the protein and crude fiber in citronella increased significantly and peaked with the protein content rose from 5.48%to 6.64%and the crude fiber from 34.96%to 36.65%.In 2-4 months,the protein content became stable ranging from 6.32%to 6.39%before a significant decline,while the crude fiber remained at 34.23%-35.77%for2-6 months.During the initial 4 months there was no significant changes on the calcium in citronella,but the content increased significantly in 5-6 month.For the first 5 months,the phosphorus content decreased initially followed by a slow incline to reach a peak in the 6 th month.Up till 3 months of silage,the fermented citronella was judged to have a Level 1 sensory score with maximized contents on amino acids,crude fat,and ash as well as a constantly high crude protein content.Afterward,however,the sensory score dropped to Level 2 with decreasing crude protein,amino acid,crude ash,and crude fat contents with a deteriorated quality.【Conclusion】It appeared that 1-3 month of silage would allow citronella to reach the highest nutrient level and prolonged storage could considerably ill-affect the forage quality.