中文摘要：

为了研究甘南碌曲和合作地区冬夏季节高寒天然牧草的生产特性、营养成分和饲用价值,试验通过化学分析法结合牧草品质评定预测公式,采用对比试验设计,试验处理为4种来自甘南碌曲和合作的夏季和冬季牧草,分别记为碌曲夏季牧草、碌曲冬季牧草、合作夏季牧草、合作冬季牧草。结果表明,无论碌曲还是合作,夏季牧草粗蛋白（CP）、总磷（TP）含量和干物质采食量（DMI）、可消化干物质量（DDM）、粗饲料相对值（RFV）、有机物质消化率（OMD）以及产鲜草量总体上都显著高于冬季牧草（P〈0.05）,粗纤维（CF）、中性洗涤纤维（NDF）、酸性洗涤纤维（ADF）、纤维素（C）含量、钙磷比（Ca/TP）都显著低于冬季牧草（P〈0.05）。合作冬季牧草的半纤维素（HC）、无氮浸出物（NFE）含量显著低于其他牧草（P〈0.05）,钙磷比（Ca/TP）、酸性洗涤木质素（ADL）含量显著高于碌曲牧草（P〈0.05）。夏季时合作牧草干物质采食量（DMI）、粗饲料相对值（RFV）显著高于碌曲牧草（P〈0.05）。这表明甘南高寒天然牧草的营养成分、生产特性、饲用价值夏季牧草明显优于冬季牧草,碌曲牧草优于合作牧草。

英文摘要：

The growth characteristics,nutritional components and feeding value of the native forage grass from high-cold steppes（Luqu and Hezuo region of Gannan）in winter and summer were studied using four kinds of forage grass for chemical analysis and prediction models were made of forage quality evaluation in a comparison experimental design.Treatments were：forage grass from Luqu in summer（LQX）,from Luqu in winter（LQD）,from Hezuo in summer（HZX）,and from Hezuo in winter（HZD）.Compared with winter,forage grass from the two regions in summer（HZX,LQX）had higher crude protein,total phosphorus（TP）,dry matter intake（DMI）,digestible dry matter,relative feed value（RFV）,organic matter digestibility and fresh forage yield（P〈0.05）.However,they were lower in crude fibre,neutral detergent fiber,acid detergent fiber,and the ratio of Ca/TP than that in winter（HZD,LQD）（P〈0.05）.In winter,the ratio of Ca/TP and acid detergent lignin in the forage grass from Luqu（LQD,LQX）was lower than that from Hezuo（HZD,HZX）（P〈0.05）and the forage grass from Hezuo（HZD）had lower hemicellulose HC and amount of nitrogen free extract than other kinds of forage grass（P〈0.05）.In summer,DMI and RFV of the forage grass from Hezuo（HZX）were significantly higher than those from Luqu（LQX）（P〈0.05）.Growth characteristics,nutritional components,and feeding value of the forage grass from Gannan in summer were better than that in winter,and the forage grass from Luqu was better than that from Hezuo in high-cold steppes（Gannan region）.