体外产气法评价青海高原小麦秸秆与天然牧草组合效应

Associative effects evaluation of wheat straw and natural grass in Qinghai plateau by in vitro gas production technique

本研究采用体外产气法评价了青海省高原小麦秸杆分别与高山柳+黑褐苔草、藏嵩草、线叶嵩草、金露梅+珠芽蓼按0∶100、25∶75、50∶50、75∶25、100∶0比例两两组合后的发酵产气特性。结果表明,48 h产气量、理论最大产气量、产气速率以及产气延滞时间与酸性洗涤纤维(ADF)、中性洗涤纤维(NDF)均呈负相关,48 h产气量、理论最大产气量、产气速率与粗蛋白质(CP)呈正相关;小麦秸秆与藏嵩草按75∶25比例搭配的组合效应最优,小麦秸秆与高山柳+黑褐苔草、线叶嵩草、金露梅+珠芽蓼均按50∶50比例搭配的组合效应最优。因此,充分利用青海省的作物秸秆资源,发挥作物秸秆与天然草地牧草的正组合效应,能缓解我省高寒牧区冬季草场牧草不足的现状,是解决反刍家畜营养季节不平衡的有效手段之一。

Using in vitro gas production technique,the study evaluated the fermentable gas production by combining Qinghai plateau wheat straw with alpine willow-dark brown sedge,Kobresia tibetica,linear leaf Kobresia and Dasiphora fruticosa＋Macrophyllous Knotweed, respectively, in the respective proportion of 0：100,25：75,50：50,75：25 and lO0：O.The results show that：the 48 h gas production, the theoretical maximum gas production,the gas production rate ,and the delay time of gas production had negative correlations with acid detergent fiber（ADF） and neutral detergent fiber（NDF）.Howev- er, the 48 h gas production,the theoretical maximum gas production and the gas production rate had positive correlations with crude protein （CP）.Meanwhile,the associative effects of wheat straw and Kobresia tibetica by 75：25 are optimal;and the combination of wheat straw with alpine willow-dark brown sedge,linear leaf Kobresia and Dasiphora frutieosa＋Maero- phyllous Knotweed by 50：50,respectively,showed optimal associative effects.Therefore,making full use of the associative effects between Qinghai crop straw and natural pasture could ease the shortage of Qinghai pasture,which was the effective measure to solve the yak season nutrition imbalance.