体外法研究不同水平苍术精油对肉牛瘤胃发酵和养分降解率的影响

Effects of different levels of atractylodes oil on rumen fermentation and nutrients digestibility of beef cattle in vitro

为了研究苍术精油对肉牛瘤胃发酵及养分降解率的影响,采用体外批次培养法,在精粗比为20∶80的基础饲粮中添加苍术精油,添加水平分别为0%(对照组)、0.50%、1.00%、1.50%和2.00%。体外培养24 h后,检测瘤胃液的pH,菌体蛋白(MCP)、乙酸、丙酸、丁酸含量等指标。结果表明:(1)瘤胃发酵参数变化:与对照组相比,日粮中添加一定水平苍术精油经体外培养24 h后,瘤胃液总产气量、氨态氮浓度、MCP含量均无显著差异,但瘤胃液pH,乙酸、丙酸、丁酸、总挥发性脂肪酸含量及乙酸/丙酸均显著提高。(2)养分降解率变化:与对照组相比,各精油添加组的培养底物中干物质(DM)降解率无显著变化,但对酸性洗涤纤维(ADF)和中性洗涤纤维(NDF)降解率影响显著。其中1.50%精油添加组的ADF和NDF降解率分别比对照组提高了20.59%(P<0.05)和17.14%(P<0.05),CP降解率与对照组无显著差异。结果说明,添加苍术精油可调控锦江黄牛的瘤胃发酵功能,提高瘤胃养分降解率,并以1.50%添加水平最佳。

The study was conducted to determine the effects of Atractylodes oil on rumen felTnent and nutrient degradability of beef cattle.An in vitro batch culture method was used in the study,and a basal diet with concentrate to forage ratio of 20 ： 80 was supplemented with Atractylodes oil by 0%, 0.50%, 1.00%, 1.50% and 2.00%, respectively.The results showed that： （1）Rumen fermentation parameters：compared with the control group,diets supplemented with A- tractylodes oil increased rumen fluid pH,acetic acid,propionic acid,butyric acid and acetic acid butyric acid,but there was no significant difference on total gas production and the concentration of microbial protein （MCP） and NH3-N among all treatments. （2）Nutrient degradability：compared with the control group, diets supplemented with atractylodes oil had no significant change on the degradability of dry matterl （DM）,but the degradation rate of acid detergent fiber （ADF） and neutral detergent fiber（NDF） of 1.5%Atractylodes oil addition group were increased by 20.53% （P 〈 0.05） and 17.14% （P 〈 0.05）respectively.These results suggest that Atractylodes oil supplemented in basic diet improved rumen fermentation function of Jinjiang yellow cattle, and increased ruminal nutrient degradation rate.The best adding level was 1.5%.