初花期骆驼刺与苜蓿混贮对降解效果的影响（英文）

目的]研究初花期骆驼刺与苜蓿混贮对降解效果的影响,为生产实践提供理论依据。方法]以初花期骆驼刺、苜蓿为材料,采用人工瘤胃技术,分析体外降解率、产气量及降解液pH值、氨态氮（NH3-N）、挥发性脂肪酸（VFA）含量的变化,研究初花期骆驼刺和苜蓿混合青贮对降解效果的影响,并确定骆驼刺与苜蓿合适的混贮比例。结果]与单一苜蓿相比,骆驼刺与苜蓿混合青贮后,能极显著降低降解液中氨态氮含量,产气量有所下降,乙酸、丙酸和丁酸含量显著增加;骆驼刺70%＋苜蓿30%的氨态氮含量（22.93mmol/L）和产气量（40.50ml）最低,降解率（32.27%）、乙酸（5.48mmol/L）、丙酸（2.08mmol/L）、丁酸（2.52mmol/L）含量及三者总量（10.08mmol/L）均最高,所以降解效果最好。结论]初花期骆驼刺与苜蓿混贮,能提高苜蓿中蛋白质和碳水化合物的利用效率,骆驼刺70%＋苜蓿30%的降解效果最好。

Effect of Mixed Silage of Alhagi sparsifolia and Medicago sativa at Initial Flowering Stage on Degradation

Objective] The influence of mixed silage of A.sparsifolia and M.sativa at initial flowering stage on degradation was studied to provide theoretical basis for production practice.Method] Using A.sparsifolia and M.sativa at initial flowering stage as materials,the changes of in vitro degradation rate,gas production,pH value,ammoniacal nitrogen（NH3-N）and volatile fatty acid（VFA）content in degradation solution were analyzed by means of artificial rumen technique,and the effect of mixed silage of A.sparsifolia and M.sativa at initial flowering stage on degradation was studied in order to find out suitable mixed silage ratio of A.sparsifolia and M.sativa.Result] Compared with single M.sativa,NH3-N content in degradation solution was very significantly decreased in the mixed silage of A.sparsifolia and M.sativa,and there was a reduction in gas production,while the content of acetic acid,propionic acid and butyric acid increased significantly;for the treatment of 70% A.sparsifolia and 30% M.sativa,NH3-N content（22.93 mmol/L）and gas production（40.50 ml）was lowest,while degradation rate（32.27%）,acetic acid（5.48 mmol/L）,propionic acid（2.08 mmol/L）,butyric acid（2.52 mmol/L）and their total content（10.08 mmol/L）were highest,so its degradation effect was the best.Conclusion] The mixed silage of A.sparsifolia and M.sativa at initial flowering stage could improve the utilization efficiency of protein and carbohydrate in M.sativa and the treatment of 70% A.sparsifolia and 30% M.sativa had the best degradation effect.