Trend of nutrient components and rumen degradability of cluster leaf rosinweed at different growth stages | 串叶松香草不同生育期营养成分及其绵羊瘤胃降解动态

chinois. 研究不同生育期串叶松香草的营养成分变化及其瘤胃降解动态，为其适宜收获期的选择提供参考。测定串叶松香草在叶丛期、抽苔期、开花期和成熟期的营养成分含量，同时选择装有永久性瘤胃瘘管的小尾寒羊与杜泊羊杂交一代羊6只，测定各生育期常规营养的瘤胃降解动态。不同生育期串叶松香草中粗蛋白（CP）、中性洗涤纤维（NDF）、酸性洗涤纤维（ADF）、钙（Ca）、磷（P）含量差异显著（P＜0.05），其中CP含量随生育期的推进呈下降趋势,NDF、ADF含量呈“高-低-高-低”的变化趋势，Ca、P含量在抽苔期最高，成熟期最低；随生育期的推进，串叶松香草总氨基酸（TAA）含量、TAA/CP和总必需氨基酸/非必需氨基酸（TEAA/NEAA）均呈“高-低-高-低”的双峰变化趋势；干物质DM、CP和NDF的瘤胃有效降解率，均随串叶松香草生育期的推进呈明显下降趋势（P＜0.01）,其中CP和DM的有效降解率相当（71％～86％），NDF的有效降解率最低（51％～66％）。综合考虑串叶松香草不同生育期的营养成分、瘤胃降解动态及产量，建议在抽苔期至开花期刈割利用为宜。

anglais. This paper was engaged in the study on the trend of nutrient components and rumen degradation characteristics of cluster leaf rosinweed at different growth stages. This paper studied the dynamic pattern of nutrient components (amino acids) of cluster leaf rosinweed at different growth periods. Six sheep fitted with permanent ruminal cannulas were used to determine the degradation profiles of nutrient components at different growth periods in the rumen by nylon-bag technique. The results showed that significant differences existed in CP, NDF, ADF, Ca and P content at different growth stages (P＜0.05). With the maturity, CP content decreased, NDF and ADF varied with the trend of high-low-high-low, TAA, TAA/CP and TEAA/NEAA with the double apex trend of high-low-high-low with the growth stages progressing. Rumen degradability of nutrient components took on evident downtrend with the maturity (P＜0.01), CP and DM were consistent but NDF was the lowest. Given nutrient components, rumen degradation characteristics and output, it’s advisable that cluster leaf rosinweed be utilized between stem elongation to flowering stage.