刈割时间对杂交狼尾草青贮质量与营养成分含量的影响

Effect of Cutting Time on the Silage Quality and Nutritional Contents of Pennisetum americanum×P. purpureum

为了确定制作杂交狼尾草青贮的刈割时间，本试验研究了北京地区不同刈割时间对杂交狼尾草青贮质量与营养成分含量的影响。杂交狼尾草于2008年4月8日返青，分别在5月18日、5月28日、6月7日、6月17日、6月27日和7月7日刈割并青贮，2008年10月7日开封，分别测定各杂交狼尾草青贮样本的感官评分、有机酸含量与组成、氨态氮／总氮比值、营养成分含量。结果表明，在返青后40～90d之间刈割，杂交狼尾草均可制作青贮，能够在北京地区进行推广应用。

In order to determine the optimum cutting time of Pennisetum americanum×P, purpureum, the quality and nutritional contents of the silages made from Pennisetum americanum×P, purpureum cut in different developing stage were analyzed. The Pennisetum americanum×P. purpureum turned green in April 8th, then mowed and made silage separately in May 18th, May 28th, June 7th, June 17th, June 27th and July 7th. After unsealed in October 7th, the sense scores, organic acid contents and composition, NH3-N/TN, main nutritional contents of the silages and the 48h in vitro digestibility of dry matter of the silages were determined respectively. The results showed that the Pennisetum americanum×P, purpureum could be cut to make silages between forty days and ninety days after turning green, the results can be widely applied in Beijng area.