利用批次培养法研究植物精油对瘤胃体外发酵的影响

摘要

采用4×5二因子试验设计，研究肉桂油和留兰香油对瘤胃体外发酵和饲粮降解参数的影响.结果表明：随发酵时间的延长，添加0、100、500 mg/L发酵液的肉桂油和留兰香油处理组的氨态氮(NH3-N)浓度持续升高，添加1500 mg/L处理组的 NH3-N浓度几乎没有变化，而添加500、1500 mg/L肉桂油处理组的微生物蛋白(MCP)浓度先下降后上升.与对照组相比，添加100 mg/L留兰香油处理组的MCP浓度有升高的趋势，添加1500 mg/L留兰香油却降低了 MCP 浓度(P<0.05).添加100 mg/L 留兰香油处理组在发酵后期(48、72 h)总挥发性脂肪酸(TVFA)、乙酸和丙酸的浓度显著升高(P<0.05)，而添加500、1500 mg/L肉桂油和留兰香油处理组的 TVFA、乙酸和丙酸浓度均显著下降(P<0.05).分别添加500、1500 mg/L 这2种植物精油处理组的体外干物质降解率(IVDMD)显著下降(P<0.05).综合分析，肉桂油和留兰香油的添加量为100 mg/L 时有利于调控瘤胃微生物发酵，当添加剂量大于500 mg/L时对瘤胃发酵不利.%Invitro batch fermentation trial was used to study the effect of cinnamon oil and spearmint oil with different dose levels on subsequent 72 h rumen fermentation and diet digestibility in a 4 × 5 facto-rial experimental design.The results showed that with prolonging the fermentation time,the concentrations of ammonia N (NH3-N)were continue to rise by adding 0,100 and 500 mg/L cinnamon oil and spearmint oil,and remain unchanged by adding 1 500 mg/L cinnamon oil and spearmint oil,and microbial protein (MCP)concentrations decreased and then increased with adding cinnamon oil at the dose level of 500 and 1 500 mg/L.Compared with the control groups,MCP concentrations tended to increase by adding 100 mg/L spearmint oil,and decreased (P<0.05)by adding 1 500 mg/L spearmint oil.Concentrations of total volatile fatty acid (TVFA),propionate and acetate increased (P<0.05)with adding 100 mg/L spearmint oil at 48 and 72 h fermentation,and decreased (P<0.05)by adding 500 and 1 500 mg/L spearmint oil and cinnamon oil.At the dose level of 500 and 1 500 mg/L,spearmint oil and cinnamon oil all decreased (P<0.05)the invitro dry matter digestibility (IVDMD).In general,the addition of spearmint oil and cinnamon oil may be beneficial to manipulate rumen microbial fermentation at the dose level of 100 mg/L,and harm-ful to the rumen fermentation at the dose more than 500 mg/L.