【作者】 曹秀青；

【导师】 刘大森；

【作者基本信息】 东北农业大学 ， 动物营养与饲料科学， 2009， 硕士

【摘要】 共轭亚油酸（CLA）是含共轭双键的亚油酸几何和位置异构体的总称,对健康有许多有益作用。日粮补充脂肪,特别是富含亚油酸的植物油,可以提高反刍动物产品中CLA的含量。近年来,关于反刍动物日粮中补充脂肪这一方式对瘤胃内环境的影响和对反刍动物产品中脂肪酸组成的改变的研究很多。本试验在日粮精粗比为40:60的条件下,以亚油酸为基准,添加4%花生油、2.84%玉米油或2.86%大豆油,使加油组亚油酸水平相同,同时花生油处理组油酸的水平是玉米油处理组的2倍,大豆油组油酸和亚麻酸含量之和与玉米油处理组中的油酸含量相等,且大豆油组中油酸和亚麻酸之比为3:1。试验选取4只雄性、健康、安装有永久性瘤胃瘘管的成年东北半细毛羊和陶赛特杂交后代,体重40±1kg,采用4×4拉丁方设计,每期试验16d,研究按等亚油酸水平添加不同植物油对绵羊瘤胃内环境、血液指标以及瘤胃液和血浆中脂肪酸组成的影响。试验分以下4部分:一、不同植物油对瘤胃内环境的的影响:每期试验第1天采集瘤胃液和内容物用于测定pH值、NH₃-N浓度、原虫数量、各主要VFA浓度及植物细胞壁降解酶活性。研究表明,植物油对绵羊瘤胃液pH值、NH₃-N浓度、乙酸浓度、丙酸浓度、丁酸浓度、乙丙酸比例、TVFA浓度及各脂肪酸的比例无显著影响（P＞0.05）,乙丙酸比例有降低的趋势。花生油处理组原虫数量比对照组降低了42.18%（P＜0.05）,玉米油和大豆油处理组原虫数量与对照组相比有降低的趋势,但差异不显著（P＞0.05）。花生油处理组滤纸纤维素酶、CMCase、葡萄糖苷酶和果胶酶活性分别比对照组降低了17.52%、17.98%、17.95%和24.27%（P＜0.05）;大豆油处理组中这4种酶活性与对照组相比呈降低的趋势,但差异不显著（P＞0.05）;玉米油处理组中这4种酶活性与对照组相比差异不显著（P＞0.05）,但呈升高的趋势。3个加油处理组木聚糖酶活性与对照组相比差异均不显著（P＞0.05）,花生油和大豆油处理组有降低的趋势,而玉米油处理组有升高的趋势。二、不同植物油对血液和瘤胃液脂肪酸组成的影响:每期试验最后一天早饲前采集血液,在饲喂后分4个时间点采集瘤胃液,分别用于测定血浆和瘤胃液中脂肪酸含量。结果表明,日粮添加植物油显著提高了瘤胃液中CLA和CLA前体物t11C18:1的浓度（P＜0.05）,同时各加油处理组显著提高了瘤胃液中PUFA和SFA的浓度（P＜0.05）。各加油处理组显著提高了血浆中t11C18:1和SFA的浓度（P＜0.05）,但对其他PUFA浓度的影响差异不显著（P＞0.05）。花生油处理组瘤胃液或血浆中C18:0的浓度均显著高于其他各组（P＞0.05）。三、不同植物油对血清指标的影响:每期试验最后一天早饲前采集血液,制备血清用于测定各项血液指标。日粮添加植物油,绵羊血清中与脂类代谢有关的TG、CHOL、HDL和LDL等指标的浓度呈升高的趋势,玉米油和大豆油处理组显著提高了血清中CHOL和LDL的浓度（P＜0.05）。添加植物油对T-AOC的影响无明显规律,有降低MDA浓度和提高SOD活性的趋势,但差异不显著（P＞0.05）。添加植物油对胰岛素含量的影响无规律性,花生油处理组血清leptin水平较对照组提高了19.29%（P＜0.05）,玉米油和大豆油处理组与对照组相比差异不显著（P＞0.05）。各加油处理组对其他生化指标的影响差异不显著（P＞0.05）。四、不同植物油对营养物质瘤胃消失率和全消化道消化率的影响:每期试验的第2、3、4、5天投放尼龙袋用于测定日粮营养物质瘤胃消失率,采集粪便利用AIA测定全消化道营养物质表观消化率。试验结果表明,与对照组相比玉米油和大豆油处理组对DM、CP和NDF的瘤胃降解无影响（P＞0.05）,花生油处理组除对NDF的瘤胃降解有抑制作用外（P＜0.05）,对DM和CP的瘤胃降解无影响（P＞0.05）。各加油处理组中DM、CP、NDF和ADF的全消化道表观消化率与对照组相比差异不显著（P＞0.05）,但是显著提高了EE的全消化道表观消化率（P＜0.05）。综上所述,日粮添加4%花生油、2.84%玉米油或2.86%大豆油可显著提高瘤胃液或血液中CLA前体物t11C18:1和CLA的浓度,且日粮中亚油酸添加水平相同时作用效果无显著性差异,油酸和亚麻酸对CLA及其前体物t11C18:1的累积未发现有影响。从此结果可能得出,通过添加富含亚油酸的植物油来调控反刍动物产品中CLA的含量,可根据植物油中亚油酸的含量进行添加。但由于花生油添加量大、价格较贵且对瘤胃内环境产生了一定的负面作用,同时玉米油的价格较大豆油为高,所以从植物油的作用效果与经济效益两方面考虑,花生油不如玉米油和大豆油,同时大豆油比玉米油经济实用。更多还原

【Abstract】 Conjugated linoleic acid（CLA）,a mixture of positional and geometric isomers of linoleic acid with conjugated double bonds,possesses many potentially beneficial effects to health. Supplementing ruminant animal diets with fat,especially vegetable oils rich in linoleic acid has been demonstrated to be an effective strategy to enrich ruminant products with CLA.Recent years, many experiments about supplementing ruminant animal diets with fat has been investigated as a means to influence a variety of ruminal environment parameters or to alter fatty acid profile of food products derived from ruminant animals.The objective of this study was to determine the effects of the addition of vegetable oils in equal-level of linoleic acid on ruminal fermentation,blood indexes, fatty acids profiles in rumen fluid and plasma.Four healthy crossbred of northeast semi-fine wool and dorset male sheep（BW=40±1kg） fitted with ruminal cannulas were used in a 4×4 Latin square design with 16d periods.Dies were 60%chinensis and 40%concentrate,and a control diet with no added fat.Peanut oil,corn oil,or soybean oil was added to high fiber diets at 4%,2.84%,or 2.86%of the dietary air-dry matter.After adding vegetable oil,linoleic acid was in the same level in each oil supplemented treatment diet,and the level of oleic acid in peanut oil treatment was 2 times than the corn oil treatment,the total content of oleic acid and linolenic acid in soybean oil treatment was equal to the content of oleic acid in corn oil treatment,the ratio of oleic acid to linolenic acid was 3:1 in soybean oil treatment.This experiment included the following 4 parts:Part 1:Effects of vegetable oils on ruminal environment.Ruminal samples were collected on the first day of each period and analyzed for ruminal pH,NH₃-N concentration,protozoal counts, major VFA concentrations,acetate to propionate ratio,and the cell wall degrading enzymes activities.Results showed that vegetable oils had no effect（P＞0.05） on ruminal pH,and NH₃-N, acetate,propionate,butyrate,TVFA concentrations,and acetate-to-propionate ratio,the proportion of each major VFA in rumen fluid,but the acetate to propionate ratio presented a decreasing tendency.Supplementing peanut oil in sheep diets decreased（P＜0.05） the protozoal counts in rumen fluid by 42.18%compared with sheep in the control diet.Corn oil or soybean oil also decreased the protozoal counts,but did not differ（P＞0.05）.Supplementing peanut oil decreased （P＜0.05） the activities of FPase,CMCase,glucosidase,and pectase in rumen contents by 17.52%, 17.98%,17.95%,and 24.27%,respectively.Soybean oil treatment decreased the 4 cellulase activities in sheep rumen contents,but did not differ（P＞0.05）.Corn oil treatment had a trend of increasing（P＞0.05） the 4 cellulase activities.However,supplementing vegetable oils did not affect the xylanase activity in sheep rumen contents,and there is a decreasing tendency in peanut and soybean oil treatments,and an increasing tendency in corn oil treatment.Part 2:Effects of vegetable oils on fatty acids profiles in plasma and rumen fluid.Blood samples were collected before morning feeding and rumen fluid samples were collected 4 times after morning feeding on the last day of each period and analyzed for fatty acids profile of plasma and rumen fluid.Sheep,diet supplemented with vegetable oil is helpful to the accumulation of precursor of CLA and CLA,and increased（P＜0.05） the concentration of t11C18:1 and CLA in rumen fluid compared with sheep in the control diet.Ruminal concentrations of PUFA and SFA were increased（P＜0.05） in oil supplementation treatments.The increasing contents of t11C18:1 and SFA were observed in plasma（P＜0.05）,but vegetable oil supplementation did not influence the content of PUFA in plasma.Concentration of C18:0 in rumen fluid or plasma of peanut oil treatment was greater（P＜0.05） than the other treatments.Part 3:Effects of vegetable oils on serum indexes.Blood samples were collected before morning feeding on the last day of each period and analyzed for blood serum indexes.Compared with control diet,serum TG,CHOL,HDL,and LDL levels which is associated with lipid metabolism had an increasing trend in vegetable oil treatments,and both serum CHOL and LDL levels were greater（P＜0.05） in corn oil and soybean oil treatments.Supplementing vegetable oil had no evident regularity effect on T-AOC,but had a trend of decreasing MDA contents and increasing the activities of SOD.Oil treatments did not influence insulin concentration but had a trend to increased serum leptin,and supplementing peanut oil increased（P＜0.05） leptin level by 19.29%,and no significant increasing in corn and soybean oil treatments（P＞0.05）.Supplementing vegetable oil did not influence the other biochemical indexes（P＞0.05）.Part 4:In this part we studied the effects of the addition of vegetable oils to the concentrate portion of total mixed diets on ruminal and total tract digestibilities of nutrients.Rumen digestibilities of DM,CP,and NDF were measured by the nylon bag technique and nutrient total tract digestibilities by AIA on the 2,3,4,and 5 day of each period.Rumen digestibilities of DM,CP, and NDF did not differ（P＞0.05） among diets except for the negative associative effect on the disappearance of NDF in peanut oil treatment.Total tract digestibilities of EE was great（P＜0.05） for the diets containing vegetable oils than for the control diet because of trends for greater postruminal digestibilities.Apparent total tract of DM,CP,NDF,and ADF digestibilities were not different among treatments.Analysis indicated that,supplementing ruminant animal diets with 4%of peanut oil,2.84%of corn oil,or 2.86%of soybean oil could lead to the accumulation of t11C18:1（CLA precursor） and CLA in rumen fluid and plasma,and the influence had no differ when diets contained the same level of linoleic acid,and the influence of oleic acid or linolenic acid on the concentration of CLA and its precursor was not observed.It might conclude that,in the means of supplementing diets with different vegetable oils to enrich ruminant products with CLA,the amount could base on the content of linoleic acid in vegetable oil.But the amount and cost of peanut oil was greater than the other oils,and the peanut oil in this level had some inhibition on ruminal fermentation.The price of corn oil was greater than soybean oil.So considering from the two sides of action effect and economic benefit,corn oil and soybean oil are better than peanut oil in improving the CLA content in ruminant production,and soybean oil are more economical than corn oil.更多还原