日粮中添加黄芪多糖对锦江黄牛瘤胃体外发酵及养分降解率的影响

Effects of Astragalus Polysaccharides (APS) on Rumen Fermentation and Nutrient Degradability of Jinjiang Yellow Cattle in Vitro

中文关键词: 黄芪多糖  锦江黄牛  瘤胃  体外发酵  养分降解率

英文关键词: astragalus polysaccharide  jinjiang yellow cattle  rumen  in vitro fermentation  nutrient degradability

中文摘要:

      [目的]试验旨在探究不同水平黄芪多糖（astragalus Polysaccharides，APS）对锦江黄牛瘤胃体外发酵指标及养分降解率的影响。[方法]选取4头健康并安装永久瘤胃瘘管的锦江黄牛公牛，采集瘤胃液。采用单因素试验设计，试验分为6组，每组4个重复，在基础日粮中分别添加0、0.25%、0.5%、1.0%、2.0%和4.0%的黄芪多糖，体外发酵24 h后测定发酵参数、养分降解率，并评定多项指标综合指数（MFAEI）。[结果]结果表明：与对照组相比，1.0%和2.0%添加组的瘤胃液菌体蛋白（MCP）含量均显著升高（P＜0.05）；2.0%添加组的氨态氮（NH3-N）含量显著降低（P＜0.05）；1.0%添加组的丙酸含量显著升高（P＜0.05），乙丙酸比值显著下降（P＜0.05）；0.5%、2.0%和4.0%添加组的粗蛋白（CP）降解率极显著高于对照组（P＜0.01）；各添加组的总产气量、pH、乙酸含量、干物质（DM）降解率、酸性洗涤纤维（ADF）降解率及中性洗涤纤维（NDF）降解率与对照组相比均无显著变化（P＞0.05）。MFAEI指数评定结果为1.0%组>4.0%组>0.5%组 >0.25%组>2.0%组。[结论]在体外发酵条件下，添加黄芪多糖可提高瘤胃微生物蛋白含量和丙酸浓度，降低NH3-N浓度和乙丙酸比值，其中1.0%添加量效果最佳。

英文摘要:

      [Objective] This experiment was conducted to investigate the effects of different levels of Astragalus Polysaccharides (APS) on rumen fermentation and nutrient degradability of Jinjiang yellow cattle in vitro. [Method] Four healthy Jinjiang yellow cattle with rumen fistula were selected to collect rumen fluid, and all fluid samples were mixed in vitro and divided into 6 groups as follwoing: basal diet Astragalus Polysaccharides by 0 (control group), 0.25 %, 0.5 %, 1.0 %, 2.0 %, and 4.0 %. After 24-hour in vitro fermentation, the fermentation parameters and nutrient degradability were determined. The results showed that the content of microbial protein (MCP) in the both 1.0% and 2.0% APS groups were increased significantly, and the contents of propionic acid were increased but the ratio of acetic acid and propionic acid was decreased in the 1% APS group compared to the control group (P < 0.05). The concentration of ammonia nitrogen (NH3-N) was decreased significantly in the APS 2.0% group, but the digestibility of crude protein (CP) in the 0.5 %, 2.0 %, and 4.0 % APS groups was increased significantly compared with the control group (P < 0.01). Nevertheless, there was no significant difference in total gas production, pH value, the content of acetic acid and propionic acid, acetic acid/propionic acid, the digestibility of dry matter (DM), neutral detergent fiber (NDF) and acid detergent fiber (ADF) among all groups (P > 0.05). Using multiple-factors associative?effects?index (MFAEI) analysis. [Result] The results showed the MFAEI value in 1% APS group was highest in all groups. [Conclusion] These results indicated that Astragalus polysaccharide can promote the synthesis of rumen MCP and propionic fermentatio in vitro, and the additive level of APS by 1.0% is better.