不同水平未酯化月桂酸对人工瘤胃发酵产气量的影响

利用人工瘤胃体外产气法,精粗比不同(3∶7和4∶6)的两种日粮类型分别用0%、3%、6%和9%(占基础日粮比例)的未酯化月桂酸(C12∶0)取代日粮精料作试验。结果表明,在体外发酵24、36、48、60和72 h,9%的C12∶0取代水平与不添加脂肪酸的对照相比可抑制总产气量的18.8%(P<0.01),且不受日粮类型的影响(P>0.05),发酵结束时(72 h),对瘤胃液pH值,氨氮浓度及干物质降解率没有显著影响(P>0.05);6%的取代水平可从48 h到72 h显著抑制两种日粮类型总产气量的13.2%;3%的取代水平始终不能显著抑制总产气量(P>0.05)。粗型料(精粗比3∶7)中添加9%的C12∶0对总产气量的抑制作用最大,比对照减少22.2%(60 h,P<0.01)。

Effects of non-esterified lauric at different levels on in vitro gas production

The gas-suppressing effects of non-esterified lauric acid(C_(12∶0)) at different levels were investigated by using basal diets of extensive type and intensive type by the Hohenheim gas test apparatus.The significant gas-suppressing impacts(P<0.01) were observed from 24 h to 72 h incubation with 18 mg(9% of diet weight) C_(12∶0) by 18.8% (compared to control),irrespective of diet types(P>0.05).The 12 mg(6% of diet weight) C_(12∶0) supplementation reduced gas production by 13.2% from 48 h to 72 h based on two diets.The 6 mg(3% of diet weight) C_(12∶0) supplementation did not affect gas production in 72 h incubation(P>0.05).The maximum gas-suppressing impact of 22.2%(P<0.01) decreased compared to control was achieved at 18 mg C_(12∶0) at 60 h with extensive-type diet.The results support that without significant effects(P>0.05)on pH,NH_(3)-N and digestibility of dry matter in rumen fluid at 72 h,18 mg non-esterified C_(12∶0) supplementation has high methane-suppressing potential both in two base diet types.