体外产气量法研究日粮中添加不同水平棉籽油对绵羊瘤胃发酵动力学的影响

Effects of addition of different levels of cotton oil in dietary on the kinetic rumen fermentation of sheep in vitro

试验采用体外产气量法研究日粮中添加不同水平的棉籽油对绵羊瘤胃发酵功能的影响。棉籽油的添加水平分别设0(对照组)、1%、2%和3%。结果表明:日粮添加不同水平的棉籽油使人工瘤胃的最大产气量依次降低,但各处理组差异不显著(P>0.05)。与对照组相比,添加棉籽油并未显著改变发酵液pH值和NH3-N浓度。与对照组相比,添加棉籽油可以降低羧甲基纤维素酶(CMCase)和木聚糖酶(XYLase)活性,仅在发酵48h后,各处理组的CMCase活性达到显著水平(P<0.05),但各处理组差异不显著(P>0.05)。与对照组相比,随棉籽油添加水平的升高可以依次降低干物质(DM)和中性洗涤纤维(NDF)的降解率,发酵48h后,2%和3%组DM显著低于对照组(P<0.05),但两者间差异不显著(P>0.05)。与对照组相比,添加棉籽油并未显著影响总挥发酸浓度(TVFA)、乙酸摩尔百分比、丙酸摩尔百分比和乙丙酸比。

This study was conducted to investigated the effect of addition of different levels of cotton oil in dietary on rumen fermentation of sheep in vitro. The addition level of cotton oil were 0.0% （control group）, 1%, 2% and 3% respectively. The results showed that：different levels of cotton oil decreased gas production （GP） of tureen fermentation in vitro,but the treatments was not significant （P〉0.05）. Compared with the control group, cotton oil did not affected significantly pH and ammonia nitrogen （NH3-N）.Compared with the control group, cotton oil can decreased carboxymethyl cellulase（CMCase） and xylanase（XYLase） activity, CMCase of the control group were significant（P〈0.05）, but the treatments was not significant （P〉0.05） at 48 h. Compared with the control group, with increasing the addition level of cotton oil, that decreased degradation rate of dry matter（DM） and neutral detergent fiber（NDF）. At 48 h, to DM, compared with the control group,2% and 3%group were low （P〈0.05）, hut the treatments was not significant （P〉0.05）. Compared with the control group, cotton oil did not influence general volatile fatty acid concentration （TVFA）, the mole percentage of acetate and propionate, the ratio of acetate to propionate（P〉0.05）.