不同精粗比日粮添加α-亚麻酸对瘤胃体外发酵参数及生物氢化代谢产物的影响

Effects of α-linolenic acid added to dietary with different propor tion of concentration and roughage on the ruminal fermentation characteristics and the bio-hydrogenation

本试验通过体外培养法,研究在不同精粗比日粮中添加α-亚麻酸,对延边黄牛体外瘤胃发酵模式及α-亚麻酸(ALA)氢化过程的影响。试验设5个底物精粗比,即精料∶粗料分别为2∶8、4∶6、5∶5、6∶4和8∶2,各组均添加3.0%的α-亚麻酸,每组3个重复。体外培养12 h,取3、6、9、12 h时间点培养液测定体外瘤胃发酵参数和脂肪酸含量。结果显示:在各时间点,随着精料比例的增加,pH值呈上升趋势,且8∶2组与其他4组比,分别高(3 h)3%、4%、4%、3%,(6 h)9%、6%、4%、3%,(12 h)5%、4%、3%、2%(P<0.05)。添加α-亚麻酸条件下,不同粗精比对总挥发性脂肪酸(TUFA)无显著影响。6 h和12 h,乙酸浓度与精料添加比例呈反比。6∶4组丙酸浓度分别比其他4组高(6 h)29%、24%、19%、15%,(12 h)19%、17%、4%、4%(P<0.01)。8∶2组NH_3-N浓度在各时间点分别比4∶6组高43%、30%、37%(P<0.01)。随精料比例升高,各时间点的CH_4、CO_2和产气量均呈上升趋势,CH_4产量一直低于CO_2的产量。t11-C_(18)∶1浓度在整个培养时间内随粗料比例的下降而减少,在6 h时2∶8组比8∶2组高64%(P<0.01)。6 h、12 h,各组共轭亚油酸(CLA)浓度无显著差异。各时间点,c9,c12-C_(18)∶2浓度随粗料添加量下降而减少,在6 h、12 h,2∶8组比8∶2组分别高81%、93%(P<0.01);总Cln A的变化趋势与之相同,各时间点2∶8组比8∶2组分别高32%(P<0.05)、87%(P<0.01)、119%(P<0.01)。由此可见,不同精粗比日粮和α-亚麻酸影响体外瘤胃发酵参数,高精料日粮可以提高总产气量和CO_2产量,同时抑制CH_4的生成。高精料日粮通过降低TVFA含量增加瘤胃pH值。试验中添加α-亚麻酸,促进了氢化微生物对亚麻酸的氢化作用,同时抑制了亚油酸的氢化过程。

This study was conduced to detemiine the effects of different diets added α -linolenic acid on rumen femientation patterns and α-linolenic acid hydrogenation process,i/i vitro culture was applied.The trial were allocated to 5 groups,the ratio of concentrate： roughage were 8：2,6：4,5：5,4：6 and 2：8 （m/m） respectively, each group added 3.0% α - linolenic acid （m/m）.Each group had three replicates.Culture for 12 h in vitro ytake 3,6,9 and 12 h sample to measure rumenal fermentation parameters and fatty acid contents.The results showed that： at each time point,with the increase of concentrate,pH value is on the rise,and 8：2 group was higher than the other four groups for （3 h） 3 % , 4 % , 4 % , 3 % , （6 h） 9%,6%,4%,3%, （12 h）5%, 4 % ,3% ,2%（P 〈 0.05） respectively.On condition that add α-linolenic acid,the effects of different diets on TVFA were not significant.At 6h and 12 h,the concentration of acetic acid has been inversely proportional to the concentrate,propionate concentrations of 6：4 group were higher than other groups for （6 h） 2 9 % , 2 4 % , 19%,15%,（ 12 h）19%,17% , 4% ,4% （P 〈 0.01 ）.NH3-N concentration of 8：2 group were higher than 4：6 group 4 3 % , 30%,37%（P 〈 0.01）.With the increase of concentrate,CH4,CO2 and gas production showed an increasing trend at each time point,CH4 production has been lower than CO2-The concentration of til -C18：1 in the whole culture process decreased with coarse reduced.At 6 h ,2 ：8 group were higher than 8：2 group 6 4 % （P 〈 0.01）.6 h , 12 h,the CLA concentration had no significant difference.At each time point,c9 ,c 12 - C18 ：2 concentrations decreased with coarse reduced,at 6 h and 12 h ,2：8 group were higher than 8：2 group 8 1 % , 9 3 % （P〈0.01） ; total ClnA have the same changetrend,at each time point 2：8 group were higher than 8： 2 group 3 2 % （P 〈 0.05）, 8 7 % （P 〈 0.01）,119%（P 〈 0.01）.Thus different diets added α-linolenic acid hasinfluenced rumen fermentation parameters in vitro,high concentrate could increase the total gas production and CO2 production, while inhibit the CH4 production.High concentrate increased pH value by reducing TVFA.Add α-linolenic acid could promote the hydrogenation of linolenic acid and inhibit the hydrogenation of linoleate.