松嫩平原农牧交错区绵羊放牧系统粗饲料的链烷特征

N-alkanes characteristic of roughage from the sheep grazing system in the Songnen Plain farming-pastoral zone

链烷是一类普遍存在于植物表皮蜡质中的饱和直链碳氢化合物,应用链烷技术可以测定放牧动物采食量和食性组成,本试验采用气相色谱法对松嫩平原农牧交错区绵羊放牧系统（人工和天然羊草草地.玉米和大豆农田残茬）中主要粗饲料的链烷含量和特征进行了分析,以期为农牧交错区放牧绵羊营养研究提供基础数据.试验结果表明,松嫩平原草地和农田残茬饲料资源所含的链烷具有明显的种间特征,在C21-C35链烷之间,奇数链烷的含量总体上高于偶数链烷的含量,不同生长时期的全株羊草.5月份的野稗和碱蒿.5和8月份的苣荬菜.8月份的狗尾草.大豆和玉米残茬的茎.叶.荚中均以C31含量最为丰富,马蔺C29含量最为丰富,而羊草穗.7月份野稗.8月份的碱蒿以C27含量最为丰富.

Alkanes are saturated hydrocarbons in the cuticular wax of plants, which can he used as a marker for determination of dry matter intake and diet selection by grazing ruminants. The concentrations and profiles of alkanes from roughage （introduced and natural Leymus chinensis grassland, maize, and soybean residues）, were analysed to provide basic data for research on grazing sheep in the farming-pastoral zone of the Songnen Plain. The n-alkane profiles of forage from grassland and crop residues were different from different species. In the range of C21- C35, the content of odd n-alkanes were more abundant than those of the even n-alkanes. Whole L. chinensis at different growth stages, Echinochloa crusgalli, and Artemisia anethifolia collected in May, Sonchus bracyotus growing in May and August, Setaria viridis, and stems, leaves, and pods of Glycine max and Zea mays crop residues, had the maximum alkane concentration for C31. The concentration of C29 n-alkanes was most abundant in Iris ensata and ear heads of L. chinensis and E. crusgalli in July while A. anethi folia had a maximum alkane concentration for C27 in August.