青海高原苜蓿青干草与农作物秸秆组合效应评价

采用体外产气法评价青海高原农牧交错区苜蓿青干草按不同质量比(0∶100、25∶75、50∶50、75∶25、100∶0)分别与小麦秸、蚕豆秸、马铃薯秸和油菜秸两两组合后的发酵产气特性。结果表明,48h产气量及理论最大产气量与有机物、粗蛋白、中性洗涤可溶物均呈极显著正相关(P<0.01),而分别与酸性洗涤纤维(P<0.001)、中性洗涤纤维(P<0.01)、中性洗涤可溶物/粗蛋白(P<0.01)呈负相关;产气速率常数分别与粗蛋白(P<0.001)、中性洗涤可溶物(P<0.001)、有机物(P<0.01)呈正相关,而分别与酸性洗涤纤维(P<0.001)、中性洗涤纤维(P<0.001)、中性洗涤可溶物/粗蛋白(P<0.001)、半纤维素(P<0.05)呈负相关;产气延滞时间与其他养分间的相关性不明显,仅与有机物(P<0.01)呈负相关。当苜蓿青干草分别与小麦秸、马铃薯秸和油菜秸均以25∶75的质量比组合、苜蓿青干草与蚕豆秸以50∶50质量比组合时较为合适。因此,适当添补易发酵或高蛋白含量的饲草能够提高农作物秸秆的利用率。

Evaluation of Associate Effects of Alfafa Green Hay and Crops Straws in Qinghai Plateau

Using in vitro gas production techniques,this study was conducted to evaluate fermentation characteristics of mixed forages of alfafa green hay with wheat straw,beans straw,rape straw,and potato straw at the mass ratios of 0∶100,25∶75,50∶50,75∶25 and 100∶0 in farming-pastoral areas of Qinghai plateau,respectively.The results showed that 48 h gas production and theoretical maximum gas production were positively related to the content of OM(P<0.01),CP(P<0.01),NDS(P<0.01),and negatively related to the content of ADF(P<0.001),NDF(P<0.01),NDS/CP(P<0.01).Gas producing velocity were positively related to the content of CP(P<0.001),NDS(P<0.001),OM(P<0.01),and negatively related to the content of ADF(P<0.001),NDF(P<0.001),NDS/CP(P<0.001),HC(P<0.05).The lag times were not obviously related to forage nutrients,only negatively related to the content of OM(P<0.01).When the mixture of alfafa green hay were mixed with four straws respectively,alfalfa green hay was mixed with wheat straw,rape straw,potato straw all with the proportion of 25∶75 and beans straw with the proportion of 50∶50 were relatively appropriate.Therefore,adding pastures rich in fermentable carbohydrate or digestible protein into low quality forage is to improve utilization efficiency of crops straws.