【作者】 于安乐；

【导师】 高巍；

【作者基本信息】 石河子大学 ， 动物营养与饲料科学， 2008， 硕士

【摘要】 本论文通过以下4个试验开展日粮中添加不同油脂对绵羊瘤胃发酵和泌乳羊乳脂脂肪酸组成的影响研究。试验1:本试验应用体外产气量法研究了在日粮中添加不同油脂(棉籽油、葵花油、红花油和鱼油)对绵羊瘤胃发酵的影响。每种油脂的添加水平分别设0.0%(对照组)、1%、2%和3%,最终选出每种油脂在日粮中最佳添加水平。结果表明:①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活(CMCase)和木聚糖酶活(XYLanase),仅在发酵48小时后,各处理组的CMCase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)、中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)的降解率,发酵48小时后,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);发酵72小时后,2%组ADF与对照组极显著(P<0.01),3%组与对照组差异显著(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)、乙酸摩尔百分百、丙酸摩尔百分比和已丙酸比。②日粮添加不同水平的葵花油使人工瘤胃的最大产气量依次降低,并且2%和3%组与对照组间差异显著(P<0.05),但两者间差异不显著(P>0.05)。与对照组相比,添加葵花油并未显著改变发酵液pH值和NH3-N浓度。与对照组相比,添加葵花油可以降低CMCase和XYLanase,仅在发酵24小时后,2%和3%组的CMCase与对照组间差异显著(P<0.05),但两者间差异不显著(P>0.05)。与对照组相比,随葵花油添加水平的升高并未显著降低DM、NDF和ADF的降解率(P>0.05)。与对照组相比,添加葵花油并未显著影响TVFA、乙酸摩尔百分百、丙酸摩尔百分比、丁酸摩尔百分百和已丙酸比。③与对照组相比,随红花油添加水平的增加使最大产气量依次降低,但是各处理组差异不显著(P>0.05)。与对照组相比,添加红花油对发酵液中pH值、NH3-N浓度、CMCase和XYLanase没有明显影响(P>0.05),但随添加水平的增加,可以降低CMCase和XYLanase。与对照组相比,随红花油添加水平的升高可以依次降低DM、NDF和ADF的降解率,发酵72小时后,各处理组NDF达到显著水平(P<0.05),但各处理组间差异不显著(P>0.05);发酵24小时后,各处理组ADF达到显著水平(P<0.05),但各处理组间差异不显著(P>0.05)。与对照组相比,添加红花油并未显著影响TVFA、乙酸摩尔百分百、丙酸摩尔百分比、丁酸摩尔百分百和已丙酸比。④日粮添加不同水平的鱼油使人工瘤胃的最大产气量显著降低(P<0.05)。与对照组相比,发酵72小时后,添加2%和3%的鱼油可显著升高发酵液中pH值(P<0.05)。与对照组相比,添加鱼油不影响发酵液的NH3-N浓度。与对照组相比,发酵24小时后,添加2%和3%的鱼油显著降低CMCase (P<0.05),发酵48小时后,添加2%和3%的鱼油极显著降低CMCase (P<0.01)。发酵48小时后,添加3%的鱼油显著降低XYLanase (P<0.05)。添加鱼油后,随添加水平的升高可显著降低DM、NDF和ADF降解率(P<0.05)。与对照组相比,添加鱼油并未显著影响TVFA、丙酸摩尔百分比、丁酸摩尔百分百和已丙酸比。与对照组相比,添加2%和3%的鱼油显著降低了乙酸摩尔百分百(P<0.05),对于已丙酸比,添加2%鱼油达到显著水平(P<0.05),添加3%鱼油达到极显著水平(P<0.01)。综合以上分析,在既要不影响体外发酵参数,又要考虑在后面动物试验中添加脂肪后对乳脂脂肪酸组成的影响,确定在本试验条件下,三种植物油的最佳添加量为3%DM,鱼油的最佳添加量为1%DM。试验2:本试验利用体外产气量法、薄层层析和气相色谱技术研究在体外培养24小时后,绵羊日粮中添加4种不同油脂(棉籽油、葵花油、红花油和鱼油)对瘤胃脂肪水解氢化程度的影响。试验采用单因子试验设计,三种植物油的添加水平为3%DM,鱼油的添加水平为1%DM。结果表明:①添加油脂可显著提高瘤胃内脂肪的水解率(P<0.05),对照组、棉籽油组、葵花油组、红花油和鱼油组的水解率分别为63.84%、74.82%、81.89%、83.02%、72.49%。②日粮中油脂后,瘤胃中C16:0、C18:0、C18:1和C18:2的比例显著增加(P<0.05);除棉籽油组外,添加其它三种油脂后的饱和脂肪酸与不饱和脂肪酸的比例显著低于对照组(P<0.05),但三组间差异不显著,其中红花组的比例最低。试验3:本试验利用体外产气量法、薄层层析和气相色谱技术研究在体外培养24小时后,绵羊日粮中添加不同的油脂组合(棉籽鱼油组、葵花鱼油组、红花鱼油组)对瘤胃脂肪水解氢化程度的影响。试验采用单因子试验设计,油脂总的添加水平为3%DM,鱼油的添加水平为1%DM。结果表明:①添加油脂组合可显著提高瘤胃内脂肪的水解率(P<0.05),其中葵花鱼油组的水解率最高为79.88%,但它与红花鱼油组差异不显著(P>0.05),与棉籽鱼油组差异显著(P<0.05)。②日粮中添加油脂后,瘤胃中C16:0、C18:0、C18:1和C18:2的比例显著增加(P<0.05),其中在各种酸的增加幅度上,以C18:1最为明显。除棉籽鱼油组外,添加其它两种油脂组合后的饱和脂肪酸与不饱和脂肪酸的比例极显著低于对照组(P<0.01),但两组间差异不显著,其中红花鱼油组的比例最低。试验4:本试验通过饲养试验研究了绵羊日粮中添加不同的油脂组合(棉籽鱼油组、葵花鱼油组、红花鱼油组)对乳脂脂肪酸组成的影响,为改变乳脂脂肪酸组成,提高乳品质寻找合适的途径。试验选取4只产子数相同,体况相近的泌乳母羊,采用单因子试验设计。绵羊基础日粮由苜蓿干草、棉籽壳、青贮玉米、精料组成,日粮精粗比为50:50。处理组油脂总的添加水平为3%DM,其中,鱼油的添加水平为1%DM。为每个试验期为8天,前5天为预饲期,后3天为正饲期。结果表明:日粮中添加不同油脂的组合后,乳脂中饱和脂肪酸除C18:0外,C8:0、C10:0、C12:0、C14:0和C16:0含量有不同程度的降低,其中,与对照组相比,各处理组的C8:0、C10:0、C16:0含量显著低于对照组(P<0.05)。日粮中添加不同油脂的组合后,乳脂中不饱和脂肪酸含量均有不同程度的升高。与对照组相比,各处理组C16:1含量差异显著(P<0.05);除葵花鱼油组外,其余各组C18:1含量显著高于对照组(P<0.05);除棉籽鱼油组外,其余各组C18:2含量显著高于对照组(P<0.05)。其中以红花鱼油组效果最好。通过以上分析可知,日粮中添加不同油脂的组合后,明显改善了乳脂中脂肪酸组成,使它向着有利于人类健康的方向发展,其中葵花鱼油组和红花鱼油组的效果比较好。更多还原

【Abstract】 Four experiments were conducted to research the effect of addition of different fats in dietary on rumen fermentation of sheep in vitro and fatty acid profiles in milk fat from lactating ewe.Experiment 1:The objective of this study was to investigate the effect of addition of different fats in dietary on rumen fermentation of sheep in vitro.The addition levels of fats were 0.0% (control group),1%,2%and 3% respectively.The results showed:①Different levelss of cottonseed oil de- creased the gas production(GP)of rumen fermentation in vitro,but the team was not significant (P>0.05).Compared the control group, cottonseed oil did not affected significantly pH and ammonia nitrogen(NH3-N).Compared the control group, cottonseed oil can decreased carboxymethyl cellulase (CMCase) and xylanase(XYLanase) activity,CMCase of the control group were significant(P<0.05), but the treatment was not significant (P>0.05) at 48h.Compared the control treatment,with increas- ing the addition levels of cottonseed oil,that decreased degradation rate of dry matter (DM)、neutral detergent fiber (NDF) and Acid Detergent Fiber(ADF).At 48h,to DM,compared the control group, 2% and 3%group were low(P<0.05), but the treatment was not significant (P>0.05).At 72h,to ADF, compared the control group,2% group were significantly (P<0.01),3% group were significantly (P<0.05).Compared the control group, cottonseed 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).②Different levelss of sunflower oil decreased GP of rumen fermentation in vitro,compared the control group,3% and 2% group were significantly (P<0.05), but between 2% and 3% was not significant (P>0.05).Compared the control group, sunflower oil did not affected significantly pH and NH3-N in rumen.Compared the control group, sunflower oil can decreased CMCase and XYLanase activity,at 24h, 3% and 2%group were significantly(P<0.05), but between 2% and 3% was not significant (P>0.05).Compared the control treatment,with increasing the addition levels of sunflower oil,that decreased degradation rate DM、NDF and ADF (P>0.05).Compared the control group, sunflower oil did not influenceTVFA,the mole percentage of acetate、propionate and butyrate,the ratio of acetate to propionate (P>0.05).③Compared the control group ,different levelss of safflower oil decreased GP of rumen fermentation in vitro. but among the team was not significant (P>0.05).Compared the control group, safflower oil did not affected significantly pH、NH3-N、CMCase and XYLanase activity in rumen. With increasing the addition levels of safflower oil,that decreased CMCase and XYLanase activity. Compared the control treatment,with increasing the addition levels of safflower oil,that decreased degradation rate DM、NDF and ADF. At 72h, compared the control group,NDF of the treaement group were significantly(P<0.05), but its was not significant (P>0.05). At 24h, compared the control treatment,ADF of the treaement group were significantly(P<0.05), but among its was not significant (P>0.05). Compared the control group, safflower oil did not influenceTVFA,the mole percentage of acetate、propionate and butyrate,the ratio of acetate to propionate(P>0.05).④Different levelss of fish oil decreased GP of rumen ferme- ntation in vitro(P<0.05).Compared the control group,fish oil of 2% and 3% heightened significantly pH (P<0.05) at 72h . Compared the control group, fish oil did not affected NH3-N. Compared the control group,fish oil of 2% and 3% group decreased significantly CMCase(P<0.05) at 24h. Compared the control group,fish oil of 2% and 3% group decreased significantly CMCase(P<0.01) at 48h. Compared the control group,fish oil of 3% group decreased significantly XYLanase(P<0.05) at 48h.Compared the control treatment,with increasing the addition levels of fish oil,that decreased degradation rate DM、NDF and ADF (P<0.05). Compared the control group, fish oil did not influence TVFA,the mole percenTGe of propionate and butyrate,the ratio of acetate to propionate(P>0.05). Compared the control group,fish oil of 2% and 3% group decreased significantly the mole percentage of acetate (P<0.05).To the ratio of acetate to propionate, 2% group was significantly (P<0.05),3% group was significantly (P<0.01).These results indicated that the addition levels of vegetable oil is3%of DM, the addition levels of fish oil is1%of DM.Experiment 2:The objective of this study was to investigate the effect of 4 different fats(cotton oil、sunflower oil、safflower oil and fish oil)of sheep dietary on rumen fat hydrolysis and hydrogenation by gas production in vitro、thin-layer chromatography(TLC) and gas chromatographic technique. Experiment used one way trial design the addition levels of vegetable oil is3%of DM, the addition levels of fish oil is1%of DM. The results showed:①Adding fats in diet can raise significantly fat hydrolysis rate (P<0.05), hydrolysis rate of the control group、cotton oil、sunflower oil、safflower oil and fish oil were 63.84%、74.82%、81.89%、83.02% and 72.49% respectively.②Adding fats in diet can increase significantly proportion of C16:0、C18:0、C18:1 and C18:2 (P<0.05). Beside cotton oil, others can decrease significantly SFA/UFA(P<0.05). But among the three groups was not significant,the lowest proportion is safflower group.Experiment 3:The objective of this study was to investigate the effect of different fats combinations of sheep dietary on rumen fat hydrolysis and Hydrogenation by gas production in vitro、TLC and gas chromatographic technique. Experiment used one way trial design, the overall addition levels of fats is 3%of DM, fish oil is 1%of DM.The results showed:①Adding fats combination in diet can raise significantly fat hydrolysis rate (P<0.05). Of which, hydrolysis rate of the combination of the sunflower oil and fish oil is up to 79.88 percent, but between it and safflower oil group was not significantly different(P>0.05),and between it and cotton oil was signi- ficantly(P<0.05).②Adding fats combination in diet can increase significantly proportion of C16:0、C18:0、C18:1 and C18:2 in rumen (P<0.05). In which,the rate of increase of C18:1 was most obvious in all acids. Beside cotton oil, others can decrease significantly SFA/UFA(P<0.01). But among the two groups was not significant,the lowest proportion is safflower group.Experiment 4:The objective of this study was to investigate the effect of different fats combinations of sheep dietary on composition of sheep milk fatty acids.Four sheeps of same number of young stock and approximately physical condition were used in one way trial design.All sheep were offered alfalfa hay、cottonseed、corn silage and concentrate feed. The rate of concentrate and crude is 50:50.The overall addition levels of fats was 3%of DM, in wich fish oil is 1%of DM.Each experimental period is 8 days,the last 3 day was the period of adaptation to the diet.The results showed:in addition to C18:0,content of C8:0,C10:0,C12:0,C14:0 and C16:0 in the milk fat were decreased by adding fats combination in diet.Of which, compared the control group,content of C8:0,C10:0,and C16:0 of the treatment group were significantly(P<0.05).And content of unsaturated fatty acid in the milk fat were raised by adding fats combination in diet.compared the control group,content of C16:1of the treatment group were significantly(P<0.05).In addition to combination group of the sunflower oil and fish oil,content of C18:1of others were significantly(P<0.05). In addition to combination group of cotton oil and fish oil,content of C18:2of others were significantly(P<0.05).In which, safflower oil group is best.Through the above analysis we can see that Effect of adding combination of different fats in diet to the fatty acid composition of milk fat is good.The improvement is conducive tothe development of human health.In wich , combination of sunflower oil and fish oil and combination of safflower oil and fish oil were relatively good results.更多还原