蛋鸡日粮添加CLA-Ca对蛋黄中CLA和胆固醇含量的影响

选用产蛋量相近的72周龄海兰白蛋鸡840只,随机分为7组,每组40只,重复3次。采用单因素随机试验设计,分别饲喂含1%、2%、3%、4%、5%、6%共轭亚油酸(CLA)的玉米-豆粕型日粮4周,研究了日粮添加CLA-Ca对蛋鸡生产性能、蛋黄中胆固醇含量和CLA含量的影响。结果表明,日粮中添加CLA-Ca降低了蛋鸡的生产性能,可提高蛋黄中CLA含量。日粮CLA水平在1%~6%范围内,CLA水平越高,富集速度越快,富集量越大,CLA最大富集量为692 g/枚鸡蛋,蛋黄脂肪中胆固醇含量随时间的变化总体趋势为先升后降,随日粮CLA浓度的变化趋势为CLA浓度越高,胆固醇的含量越低,但显著高于对照组(P<0.05)。     

共轭亚油酸对鹅抗氧化功能与脂质过氧化的影响

本文旨在研究不同共轭亚油酸(CLA)添加水平对五龙鹅抗氧化性能与脂质过氧化的影响。选用1日龄五龙鹅192只,随机分为4个处理组,每个处理组48只,设4个重复,每个重复12只。在玉米-豆粕型日粮基础上分别添加CLA(0.0、5.0、15.0和25.0g/kg),以饲喂基础日粮组为对照组,试验期8周,测定并观察其在第2、4、6和8周龄血清中总超氧化物歧化酶(T-SOD)和谷胱甘肽过氧化物酶(GSH-Px)活性、血清及肝脏组织中脂质过氧化物丙二醛(MDA)含量和总抗氧化能力(T-AOC)等各项指标的变化规律。结果表明:日粮添加5.0g/kgCLA时,能够显著提高鹅血清T-SOD活性(第6、8周龄)和血清(第6周龄)及肝脏组织中(第8周龄)T-AOC(P<0.05);添加15.0g/kgCLA,对鹅血清T-SOD,GSH-Px(第6、8周龄)活性及血清及肝脏T-AOC均有一定提高作用;而当添加水平为25.0g/kg时,对T-SOD,GSH-Px活性和T-AOC均有一定降低作用;不同添加水平CLA均能明显降低血清及肝脏中MDA含量(P<0.05)。本试验条件下,5.0g/kgCLA添加组对于提高和改善鹅的抗氧化功能与脂质过氧化状况效果最佳。     

EPA/DHA对体外发酵及瘤胃液脂肪酸组成的影响

试验旨在研究日粮中添加不同水平的DHA/EPA对体外发酵和瘤胃液脂肪酸变化的影响。试验通过采用持续动态人工瘤胃装置,向发酵罐中添加EPA/DHA,连续培养7 d,分析脂肪酸组成的变化及发酵模式的改变。试验结果表明,日粮添加EPA/DHA使瘤胃液pH升高（与CK相比,Trt1和Trt2分别升高了0.11和0.35）,Trt2 与CK相比差异极显著（P<0.01）;与CK相比处理组3种主要挥发酸中乙酸浓度下降（P<0.01）,丙酸浓度升高(P<0.01),丁酸浓度下降(P<0.01),总挥发性脂肪酸浓度与对照组相比略有下降但差异不显著（P>0.05）;日粮添加EPA/DHA使瘤胃液脂肪酸成分发生改变。与CK相比处理组C18∶0含量显著下降（P<0.01）; t 11 C18∶1含量显著升高（P<0.01）;c-9,t-11 CLA含量显著升高（P<0.01）,但是两组之间差异均不显著。因此,日粮中添加不同水平的EPA/DHA可以改变瘤胃发酵模式,影响不饱和脂肪酸瘤胃氢化过程,使脂肪酸组成发生改变,为采用新的营养措施调控反刍动物产品中CLA的含量提供理论依据。     

Research Progress of Nutrition Regulation on Conjugated Linoleic Acid in Rumen,Goat's Milk and Mutton

Researcher pay attention to the conjugated linoleic acid (CLA) because of its function of anticancer,antidiabetic and immunological competence in the body.A lot of researches on contents of CLA in goat that enjoy high favor among people has been carried out in recent years.The article presents the biosynthsis process of CLA in ruminal,and focus on reviewing the result of many sdudies on the effects of the contents of CLA and vaccine acid in rumen;Further treat of the effects of nutrition regulation on CLA in goat's milk and mutton.Result show that the microflora and protozoa could increase the contents of CLA in rumen by using grease mixed of regulator,and increasing the contents of CLA in animal products at the same time,and avoiding to decline the contents of milk fat.we should reveal synthesis mechanism of CLA through nutrition,molecular biology,and physiology fully in the future,to provides a theoretical basis for producting CLA-enriched mutton and milk.     

TRV病毒介导的基因沉默体系在新疆陆地棉和亚洲棉中的建立

为研究烟草脆裂病毒(Tobacco rattle virus,TRV)介导的基因沉默(Virus-induced gene silencing,VIGS)技术应用的广谱性,以陆地棉(Gossypium hirsutum)CLA1为标记基因,通过构建基因沉默载体,在新陆早33和亚洲棉(Gossypium arboreum)建立了TRV-VIGS体系。半定量PCR分析表明,与对照相比,TRV侵染的新陆早33和亚洲棉中CLA1基因的表达均被有效抑制,真叶表现出明显的白化症状。同时在45份新陆中系列棉花材料中重复该体系,并且通过控制培养温度来检验温度对VIGS的影响,结果表明,当昼/夜温度分别为23℃/21℃和32℃/28℃时,不同品种的新陆中系列棉花均可以维持不同程度的白化表型。证明,TRV介导的VIGS可以用于室内研究新陆中系列棉花和亚洲棉基因功能。     

葵花籽对羊组织共轭亚油酸沉积及相关酶基因表达的影响

研究日粮中添加葵花籽(SS)对生长羊血液、不同组织共轭亚油酸(conjugated linoleic acid,CLA)的含量、硬脂酰辅酶A去饱和酶和脂肪酸合成酶基因表达的影响,选用18只健康体重相近3月龄生长羊(公)随机分为2组,分别饲喂不含葵花籽的基础日粮(对照组)和含6%葵花籽的日粮(处理组),进行为期30d的试验。结果表明:日粮中添加葵花籽极显著提高血液中t11-C18∶1和CLA-c9,t11的含量(P<0.01),处理组羊皮下脂肪组织中CLA-c9,t11含量极显著增加(P<0.01),肾周脂肪和肝脏组织中CLA-c9,t11含量有增加趋势,背最长肌CLA-c9,t11含量无显著变化(P>0.05)。葵花籽日粮能显著提高皮下脂肪SCD基因表达量(P<0.05),但对肝脏和肾周脂肪SCD基因表达量没有显著影响(P>0.05);处理组羊肝脏和肾周脂肪FAS基因表达量显著降低(P<0.05),皮下脂肪FAS基因表达量无显著变化(P>0.05)。     

离子注入诱变植物乳杆菌选育CLA高产突变株的研究

以A6-1为出发菌株,采用N+离子注入的方法进行诱变处理,注入能量为50keV,注入剂量为1×1013、3×1013、5×1013、8×1013、10×1013、30×1013、50×1013、80×1013、100×1013ion/cm2,真空度为10-3Pa。结果显示,菌体的存活率随离子注入剂量的增加呈"马鞍型"曲线,"鞍脊"出现在30×1013ions/cm2～50×1013ions/cm2之间,此时菌体的存活率在20%～35%之间。综合考虑存活率、总突变率、正突变率和突变幅度等因素,推荐30×1013ions/cm2作为离子注入植物乳杆菌的适宜诱变剂量。从所有的注入处理中挑选CLA转化能力提高了50%以上的突变株进行传代稳定性试验,发现F菌株经8次传代后产CLA的稳定性最好。该突变株各代的产量平均为162.5μg/ml,比出发菌株提高了69.87%,将此突变菌株命名为A6-1F。     

Enrichment of channel catfish (Ictalurus punctatus) fillets with conjugated linoleic acid and omega-3 fatty acids by dietary manipulation

An experiment was conducted in aquaria with channel catfish (Ictalurus punctatus) to determine the efficacy of augmenting fillets with conjugated linoleic acid (CLA) and omega-3 highly unsaturated fatty acids (n − 3 HUFA) by feeding diets amended with products containing high levels of these nutrients. Refined menhaden fish oil at 1.5% of diet supplied the n − 3 HUFA. CLA was used at dietary levels of 0.5% and 1% with a preparation that contained approximately 65% isomers of CLA. Corn oil was added to the basal diet at maximum inclusion level for added lipids of 3% for the control diet and to adjust total added lipid content of the other diets to 3%. Average initial body weight was 57.39 ± 0.25 g/fish. Six experimental diets were fed twice daily to four replicate aquaria for six weeks. At that time, fish were group weighed for determination of weight gain and feed conversion. Fillets of six fish per aquarium were recovered and stored at − 80 °C for moisture and total lipid analyses, fatty acid analysis, and sensory evaluation. Results showed feed consumption and feed conversion did not differ (P > 0.05). Significantly (P < 0.05) greater body weight gains were observed only for fish fed the diets with two combinations of CLA and 1.5% fish oil compared to fish fed the diet containing 0.5% CLA and corn oil. Fillet n − 3 HUFA levels were significantly (P < 0.05) elevated for fish fed diets containing fish oil when compared to n − 3 HUFA of fillets of fish fed diets containing either corn oil or CLA and corn oil. Similarly, fillets from fish fed diets amended with CLA contained substantial amounts of CLA of up to 6.4% of total lipids. Fillets from fish fed corn oil or fish oil diets had no CLA. Taste panel evaluation indicated that fillets containing n − 3 HUFA and CLA were essentially without fishy off-flavor and had excellent sensory qualities. Catfish fillets produced by amending diets with sources of n − 3 HUFA and CLA at the levels used in this study would contain elevated levels of these nutraceuticals and could be an important human food source for these healthful fatty acids.     

乳脂中共轭亚油酸的生理活性研究进展

共轭亚油酸（CLA）是目前研究的热点之一，文章主要对近年来乳脂中CLA的生理活性研究进展情况作一简要概述。