Study on the changes of amino acid profiles rumen degradation for cluster leaf rosinweed and comfrey at different growth stages | 不同生育期串叶松香草和聚合草氨基酸瘤胃降解特性研究

Chinese. 研究不同生育期串叶松香草和聚合草氨基酸的瘤胃降解特性，为牧草适宜收获期的确定及其资源利用提供依据。以6头装有永久瘤胃瘘管的小尾寒羊为试验动物，用尼龙袋法测定不同生育期串叶松香草和聚合草在绵羊瘤胃降解前后氨基酸含量的变化，研究氨基酸的瘤胃降解特性。（1）随生育期的推进，串叶松香草和聚合草中氨基酸含量均呈降低趋势，串叶松香草总氨基酸/粗蛋白呈现“高-低-高-低”的双峰变化，聚合草总氨基酸/粗蛋白呈现“低-高-低”的单峰变化；2种牧草均富含天冬氨酸、谷氨酸、丙氨酸、缬氨酸和亮氨酸，而含硫氨基酸的含量均较低，但氨基酸含量随不同生育期的变化规律不尽相同。（2）在开花期，2种牧草大部分氨基酸在瘤胃中不易降解，表明2种开花期牧草的氨基酸在瘤胃中有比较好的抗降解能力，尤其以脯氨酸和丙氨酸的抗降解能力较强(P＜0.05)。（3）在除开花期以外的其他生育期，2种牧草的氨基酸在瘤胃中均较易降解；各生育期牧草赖氨酸和精氨酸在瘤胃中均较易降解(P＜0.05)。串叶松香草和聚合草的粗蛋白和氨基酸含量受品种和生育期的影响较大；2种牧草不同生育期赖氨酸和精氨酸在瘤胃中均较易降解，而开花期脯氨酸和丙氨酸在瘤胃中的抗降解能力较强。

English. This research was engaged in the study on the change of amino acid profiles rumen degradation for cluster leaf rosinweed and comfrey at different growth stages. Six sheep fitted with permanent ruminal cannulas were used to determine the degradation characteristics of amino acid (AA) ruminal incubation by nylon-bag technique for 2 forage grasses at different growth stages. The result showed that: 1) The contents of amino acid reduced gradually with the growth of 2 kinds of forages. The TAA/CP of cluster leaf rosinweed showed two-peak (high-low-high-low) dynamic pattern. The TAA/CP of comfrey showed singer-peak (low-high-low) dynamic pattern. Two kinds of grasses were rich in aspartic acid, glutamic acid, alanine, valine and leucine, while the content of sulfur amino acids-lower. But the amino acid changed at different growth stages with different rules. 2) Most amino acids of the Two kinds of grasses in the flowering were not easily degradable in the rumen, showing that amino acids in the rumen of grass flowering had good resistance to degradation for 2 kinds of grasses, especially proline and alanine degradation in the rumen of strong resistance (P＜0.05). 3) In 4 growth periods amino acids were more prone to degradation in the rumen except flowering, while the lysine and arginine were more easily degradable in the rumen grass for 2 kinds of grasses (P＜0.05). Two kinds of forage crude protein and amino acids affected by the great variety and growth stage. Lysine and arginine at different growth stages were easier to degradate in the rumen. Proline and alanine had strong anti-degradation in the rumen in flowering period.