6种长链脂肪酸对瘤胃微生物体外发酵挥发性脂肪酸浓度的影响

Effects of Six Kinds of Long-Chain Fatty Acids on Volatile Fatty Acid Concentration in Ruminal Microorganism in Vitro Fermentation

本试验主要研究6种长链脂肪酸对瘤胃微生物体外发酵挥发性脂肪酸（VFA）浓度的影响。试验分为添加3％硬脂酸（A组）、油酸（B组）、亚油酸（C组）、α-亚麻酸（D组）、花生四烯酸（E组）、二十碳五烯酸（F组）的试验组和添加3％棕榈酸钙的对照组。以3头瘘管山羊为瘤胃液供体进行体外培养，测定各组VFA浓度在24h内的动态变化。结果表明：随培养时间的延长，各组总VFA浓度总体上呈现上升趋势，其中D组持续在较高水平波动；在3、6、18h时组间差异显著（P〈0．05），并以D组最高。乙酸在总VFA中的摩尔浓度百分比总体上呈现下降的趋势，在9、18h时组间差异显著（P〈0．05），并以D组最高。丙酸在总VFA中的摩尔浓度百分比总体上则呈现上升、下降、再上升和再下降的波动变化。乙酸／丙酸在2．48～3．34间变动，除6h时A组和对照组显著高于B、c组（P〈0．05）外，其他各时间点组间的差异皆不显著（P〉0．05）。另外，丁酸在总VFA中的摩尔浓度百分比在7．62％-13．08％间变动，其中在3、6、9、18h时组间差异显著（P〈0．05），并以D组较低。综上，不同种类长链脂肪酸对瘤胃微生物体外发酵产生的VFA具有一定的调控作用，其中α-亚麻酸组的总VFA浓度较高。

This experiment was conducted to investigate the effects of six kinds of long-chain fatty acids on the concentration of volatile fatty acids （VFA） in ruminal microorganism in vitro fermentation. Seven groups were added stearnic acid （group A） , oleic acid （group B ） , linoleic acid （group C） , α-linolenic acid （group D） , arachidonic acid （ group E） , eicosapentaenoic acid （ group F） , and palmitic acid calcium （ control group） , re- spectively, at 3 % level in the culture substrates. Three goats fitted with permanent ruminal cannulas were used to provide rumen liquor for in vitro culture, and the 24-h dynamics of VFA concentration were measured. The results showed as follows： the concentration of total VFA in all groups had an upward trend in general, and group D kept fluctuating at comparatively high level. At 3,6 and 18 h, there were significant differences in to- tal VFA concentration among all groups （ P 〈 0.05）, and the group D had the highest data. The acetate molar concentration percentage in total VFA had a down trend. At 9 and 18 h, acetate molar concentration percentage in total VFA had significant differences among all groups （ P 〈 0.05 ） and the highest peak occurred in group D. The propionate molar concentration percentage in total VFA had a first upward and then down trend, and had an upward and down trend again. The acetate/propionate was changed in a range from 2.48 to 3.34, and no significant difference was detected among all groups except at 6 h （ P 〉 0.05） ; at 6 h, group A and control group were significantly higher than groups B and C （ P 〈 0.05 ）. The butyrate molar concentration percentage in total VFA was fluctuated from 7.62% to 13.08%. Significant differences were found at 3, 6, 9 and 18 h （ P 〈 0.05 ）, and group D was lower compared with other groups. Taken together, different kinds of long- chain fatty acids have certain regulatory effects on VFA in ruminal microorganism in vitro fermentation. The concentration of total VFA is higher in the α-linolenic acid group.