多不饱和脂肪酸对基因表达的影响及其机理

多不饱和脂肪酸(polyunsaturated fatty acids,PUFAs)既可作为机体的结构成分和能量来源,又可通过影响基因表达而改变脂类、糖类和蛋白质的代谢,影响细胞的增殖和分化等。文中重点综述PUFAs对动物,特别是鱼类基因表达的影响及其机理,以便研究和通过PUFAs对动物生产性能进行调控,有效提高和控制动物的生长和生产性能,促进机体的正常生长、发育和健康。     

多不饱和脂肪酸对鱼类免疫与成活的影响及机理

多不饱和脂肪酸(PUFAs)是具有重要生物学功能的独特生物活性物质,是神经和其他细胞膜的重要组分,花生碳四烯酸(AA)和二十碳五烯酸(EPA)还产生类二十烷酸调节机体炎症、T淋巴细胞和B淋巴细胞功能.PUFAs通过影响机体脂类代谢、基因表达、细胞膜功能、机体免疫及血液生化特性等对鱼类生长、发育、免疫和存活发挥重要的作用.本文主要综述PUFAs对鱼类免疫的影响与机理,探讨PUFAs通过提高免疫力而增加鱼类特别是仔稚鱼成活率的调节,以便进一步深入研究PUFAs,更好地利用PUFAs,调控提高鱼类免疫力、生长、发育和成活.     

多不饱和脂肪酸在鱼类营养与饲料中的作用及其氧化稳定性

本文综述了国内外对n-6和n-3多不饱和脂肪酸在鱼类生长和健康中的作用，以及鱼类对日粮多不饱和脂肪酸的实际需求量，针对多不饱和脂肪酸易氧化的特性，还介绍了多不饱和脂肪酸氧化稳定性的研究现状，为在生产水产商品饲料过程中更好地选择多不饱和脂肪酸抗氧化剂提供参考。     

多不饱和脂肪酸对家禽脂肪沉积的影响

脂肪是家禽体内最好的储能形式。日粮中的脂肪具有高能、提供必需脂肪酸、提高某些养分的吸收利用率和提高适口性的优点。各种脂肪来源中所含脂肪酸种类和比例的差异 ,对家禽脂肪沉积产生多样化的影响。本文阐述的是各种日粮脂肪来源中多不饱和脂肪酸 (ＰＵＦＡ)对蛋鸡 (鸡蛋 )和肉鸡 (胴体 )脂肪沉积的影响。1　ＰＵＦＡ的日粮来源日粮中ＰＵＦＡ主要来源于添加的各种油脂。每种油脂中所含各种脂肪酸及ＰＵＦＡ的比例各不相同 ,详见表 1[1] 。表 1　常见油脂的脂肪酸组成脂肪酸棕榈油牛脂鸡脂花生油菜籽油玉米油红花油豆油鲱鱼油<16Ｃ 1 4 …     

影响饲料转化率的因素

作分析了可影响饲料转化率的许多因素，如饲料浪费、鸡的活动量、鸡舍条件、疾病和死亡。种公鸡的能量摄入可影响后代的生长率。     

壳聚糖对不同品种不同日龄仔鸡生长和饲料报酬的影响

这三个实验目的在于研究壳聚糖和品种对仔鸡几个主要经济性状的影响。在实验一中,一日龄仔鸡自由采食基础日粮(对照组)或采食添加壳聚糖10.5mg/d·只的基础日粮(实验组)。在实验二和实验三中实验组从15日龄开始添加与实验一同样水平的壳聚糖。从实验一看来,实验组的平均体重从21日龄起显著重于对照组P<0.05。尤其是35日龄的平均体重,实验组分别比对照组重ArborAcres121.8g,Peterson118.5g和Ross242.8g,差异显著P<0.05。但是,在实验二和实验三中,对照组和实验组(从15日龄开始添加壳聚糖)的平均体重没有明显的差别。不同鸡种35日龄平均体重的对比:ArbolAcres显著重于Peterson和Ross,P<0.05;但是在整个实验中,Peterson和Ross及Cobb和Ross之间没有显著的差异。在实验一中,有2个鸡种(ArborAcres和Ross)15￣35日龄的平均饲料转化率(FCR)实验组显著低于对照组,P<0.05。无论实验二还是实验三,品种内各组之间15～35日龄的FCR都没有明显差异。所有3个实验中,品种之间15￣35日龄的FCR差异也不是很大。除了实验三中的Cobb,所有实验中,品种内各组之间的平均腹部脂肪沉积率也没有显著差异,其中实验一中Ross明显低于ArborAcres或Pe-terson,而实验三中Cobb低于Ross。方差分析表明整个实验中,添加壳聚糖和品种间的互作效应对于包括平均腹部脂肪沉积率在内的主要经济性状差异不明显。实验结果:从1日龄开始添加壳聚糖可以促进仔鸡生长,提高饲料转化率。     

影响蛋用鸡饲料转化率的要因

饲料费是鸡蛋生产的重要费用项目。美国表示饲料转化率的惯用做法是,生产一打鸡蛋需要多少磅饲料,是有关蛋用鸡经营中收益好坏的重要因素。每打蛋需3.5磅饲料就是相当好的,若达4.2磅饲料就不太好,转化率降低了。 影响饲料转化率有二个主要因素,就是鸡群消耗的饲料量和产蛋个数。其中之一是,鸡群     

日粮粗纤维水平对兔饲料转化率的影响

本研究由两个独立的分试验组成。试验一，日粮中不同的粗纤维含量对试兔饲料转化率的影响；试验二，不同品质的粗饲料对兔饲料转化率的影响。结果表明，试兔的饲料转化率随日粮粗纤维的水平增加而降低。在配制家兔日粮时，不能一味追求加大粗饲料的比例，否则将会降低家兔的生产性能。粗饲料的品质是影响家饲料转化率的因素之一。苜蓿草粉是家兔理想的饲草料，而小麦秸则质地粗糙，不宜饲喂家兔。在粗饲料品质过差时，则应注意占日粮     

影响蛋鸡饲料转化率的因素

在配合蛋鸡饲料时,有几个因素必须考虑。这些因素多与经济效益有关。如:饲料的能量水平,鸡舍温度,产蛋率,鸡群的日龄,每日采食量,蛋壳质量问题,某种特定原料购入的可能性。在产蛋期的各个阶段这些因素对饲料的总体改善都非常重要。以下对各因素分别作以说明。     

日粮中添加不同比例多不饱和脂肪酸对产蛋鸡抗氧化机能的影响

选用168只产蛋鸡进行试验,研究在日粮中添加不同比例多不饱和脂肪酸(PUFA)对产蛋鸡抗氧化机能的影响。采用2×2双因子试验设计。基础日粮为玉米-豆粕型日粮,n-3(PUFA)/n-6(PUFA)比例分别为1:1、1:4、1:8、1:16、1:32,维生素E(VE)添加水平为30mg/kg和300mg/kg。在试验开始后第5周和第10周测定血浆中总超氧化物歧化酶(T-SOD)、谷胱甘肽过氧化物酶(GSH-Px)、总抗氧化力(TAOC)活性及丙二醛(MDA)含量;试验结束屠宰鸡只测定肝脏匀浆液中T-SOD、GSH-Px、TAOC活性及MDA含量。试验结果表明:随着日粮中n-3(PUFA)/n-6(PUFA)比值的下降,试验鸡血浆及肝脏中T-SOD,TAOC,GSH-Px活性增加,其中血浆中T-SOD活性只有在第5周时才达到显著水平(P<0.05),而血浆中GSH-Px活性在第5周及第10周时均达到显著(P<0.05)水平;血浆和肝脏中MDA含量随着日粮中n-3/n-6比值的下降而显著(P<0.05)下降。高水平VE添加能够显著(P<0.05)提高产蛋鸡血浆和肝脏中T-SOD,TAOC,GSH-PX活性,降低血浆中MDA含量。     

多不饱和脂肪酸对海水仔稚鱼生长发育的影响及机理

多不饱和脂肪酸对鱼类特别是海水鱼类的正常繁殖、生长、发育都起着非常重要的作用,是其生命过程中不可缺少的营养因子,因而是培育和引进发展新渔业品种必须首先研究的重要课题之一。文章重点综述多不饱和脂肪酸对海水仔稚鱼生长发育的影响及其机理,以便掌握规律和调控机制,有效地应用多不饱和脂肪酸,提高海水仔稚鱼的成活率和促进健康生态养殖。     

Effect of dietary fermented fish waste on the digestion of feed and supply of unsaturated fatty acids including conjugated linoleic acid in cattles

Abstract

This study was conducted to evaluate the effect of fermented fish waste (FW) on the digestion of fiber and the flow of unsaturated fatty acids (UFA) to the duodenum and plasma in cattle. Four Holstein cows were used in a 4×4 Latin square design and cows were provided with one of four treatments consisting 0, 5.5, 11, and 16.5% of FW. The digestion of dry matter decreased as the FW increased; however, the lipid concentration increased linearly (P<0.05) as the FW increased. According to the duodenal composition, the lipid concentration and UFA such as conjugated linoleic acid (CLA), arachidonic acid, and docosahexaenoic acid (DHA) increased linearly (P<0.05) as the amount of FW increased in the diet. Additionally, the concentration of CLA, eicosapentaenoic acid and DHA increased linearly (P<0.05) in the plasma as the FW increased. Thus, these findings indicate that FW can be useful as UFA supplementation of feedstuff.     

苜蓿草粉比例对豁鹅蛋黄不饱和脂肪酸含量的影响

试验采用3×3因子设计,将日粮苜蓿草粉比例设为10%、20%、30%三个水平,蛋白质设为15.83%、14.01%、12.74%三个水平。选用180只12月龄健康产蛋豁鹅,随机分为9组,每组20只,试验期20 d。研究日粮苜蓿草粉比例和蛋白水平及二者交互作用对豁鹅蛋黄不饱和脂肪酸含量的影响。结果表明,随着日粮苜蓿草粉比例增加,蛋黄油酸和花生四烯酸含量呈显著(P<0.05)降低趋势,统计结果表明:油酸含量(x,mg/g)随日粮苜蓿草粉比例增加的变化趋势为二次函数:y=-0.05x2+0.23x+260.88,r2=0.82;蛋黄亚麻酸含量和总共轭亚油酸呈显著(P<0.05)增加趋势;随着日粮蛋白水平增加,蛋黄油酸、亚麻酸、总共轭亚油酸和花生四烯酸含量均呈显著(P<0.05)降低趋势。苜蓿草粉比例和蛋白水平的互作效应仅对花生四烯酸产生一定影响,根据比较,当苜蓿草粉比例为20%、蛋白水平为14.01%时,蛋黄亚麻酸含量和总共轭亚油酸含量最高。     

法氏囊活性肽对鸡体增重及饲料转化率的影响

把不同剂量的法氏囊活性肽 (BS)冻干粉与传染性法氏囊病 (IBD)活苗混合后 ,对 2 1日龄SPF鸡滴鼻点眼 ,同时另选一批同样生长状态的鸡 ,在颈部皮下接种IBD细胞毒油苗 ,同时肌肉注射上述不同剂量法氏囊活性肽 ,观察法氏囊活性肽对鸡生长性能的影响。结果发现 :免疫后7d ,活苗 0 2mLBS组增长最快 ,比免疫对照组多增 82 5 % ,并且饲料报酬高。但从整个试验期看 ,0 4mLBS组增重效果较好 ,比免疫对照组多增 1 9 8% ,并且有较高的饲料转化率。而肌肉注射BS组中 ,高剂量 (0 8mL)BS组的增重效果一直很好 ,比对照组总增重平均多增 7 2 3 % ,并有较高的饲料报酬。这说明滴鼻点眼或是肌肉注射 ,BS都有促生长的作用     

Effects of incremental amounts of fish oil on trans fatty acids and Butyrivibrio bacteria in continuous culture fermenters

Previous studies have shown that adding fish oil (FO) to ruminant animal diets increased vaccenic acid (VA; t11 C18:1) accumulation in the rumen. Therefore, the objective of this study was to evaluate the effect of dietary FO amounts on selected strains of rumen bacteria involved in biohydrogenation. A single‐flow continuous culture system consisting of four fermenters was used in a 4 × 4 Latin square design with four 9 days consecutive periods. Treatment diets were as follows: (i) control diet (53:47 forage to concentrate; CON), (ii) control plus FO at 0.5% (DM basis; FOL), (iii) control plus FO at 2% (DM basis; FOM) and (iv) control plus FO at 3.5% (DM basis; FOH). Fermenters were fed treatment diets three times daily at 120 g/day. Samples were collected from each fermenter on day 9 of each period at 1.5, 3 and 6 h post‐morning feeding and then composited into one sample per fermenter. Increasing dietary FO amounts resulted in a linear decrease in acetate and isobutyrate concentrations and a linear decrease in acetate‐to‐propionate ratio. Propionate, butyrate, valerate and isovalerate concentrations were not affected by FO supplementation. Concentrations of C18:0 in fermenters linearly decreased, while concentrations of t10 C18:1 and VA linearly increased as dietary FO amounts increased. The concentrations of c9t11 and t10c12 conjugated linoleic acid were not affected by FO supplementation. The DNA abundance for Butyrivibrio fibrisolvens, Butyrivibrio vaccenic acid subgroup, Butyrivibrio stearic acid subgroup and Butyrivibrio proteoclasticus linearly decreased as dietary FO amounts increased. In conclusion, FO effects on trans fatty acid accumulation in the rumen may be explained in part by FO influence on Butyrivibrio group.     

Influence of Carotino oil on in vitro rumen fermentation,metabolism and apparent biohydrogenation of fatty acids

The study appraised the effects of Carotino oil on in vitro rumen fermentation, gas production, metabolism and apparent biohydrogenation of oleic, linoleic and linolenic acids. Carotino oil was added to a basal diet (50% concentrate and 50% oil palm frond) at the rate of 0, 2, 4, 6 and 8% dry matter of the diet. Rumen inoculum was obtained from three fistulated Boer bucks and incubated with 200 mg of each treatment for 24 h at 39°C. Gas production, fermentation kinetics, in vitro organic matter digestibility (IVOMD), volatile fatty acids (VFA), in vitro dry matter digestibility (IVDMD), metabolizable energy and free fatty acids were determined. Carotino oil did not affect (P > 0.05) gas production, metabolizable energy, pH, IVOMD, IVDMD, methane, total and individual VFAs. However, Carotino oil decreased (P < 0.05) the biohydrogenation of linoleic and linolenic acids but enhanced (P < 0.05) the biohydrogenation of oleic acid. After 24 h incubation, the concentrations of stearic, palmitic, pentadecanoic, myristic, myristoleic and lauric acids decreased (P < 0.05) while the concentration of linolenic, linoleic, oleic and transvaccenic acids and conjugated linoleic acid (CLAc9t11) increased (P < 0.05) with increasing levels of Carotino oil. Carotino oil seems to enhance the accumulation of beneficial unsaturated fatty acids without disrupting rumen fermentation.     

富含十八碳不饱和脂肪酸的植物油对体外瘤胃发酵和甲烷生成的影响

选取3种典型的植物油:菜籽油、豆油和亚麻油,利用体外培养系统进行体外发酵,研究植物油的类型和添加水平对瘤胃体外发酵和甲烷生成的影响。3种植物油分别添加底物干物质的3%、5%和7%,未添加植物油组为对照,共10个处理,每个处理设3个重复。结果表明,菜籽油对甲烷产量无显著影响(P>0.05),豆油7%添加水平显著抑制了甲烷生成,而亚麻油所有添加水平均显著降低了甲烷生成量(P<0.05)。在豆油和亚麻油处理组中,随着添加水平的提高,甲烷产量线性下降(P<0.01)。3种植物油均显著改变了瘤胃发酵模式,随着植物油中所含不饱和脂肪酸不饱和度的增加,乙酸和丁酸的摩尔比例显著降低,丙酸摩尔比例显著升高(P<0.05);植物油添加水平的提高显著降低了乙酸和丁酸摩尔比例,显著升高了丙酸摩尔比例(P<0.05),乙酸丙酸比例显著降低。本试验结果表明植物油降低甲烷的效果跟其来源和添加水平有关;随着植物油添加水平的提高和所含不饱和脂肪酸不饱和度的增加,甲烷生成量显著降低。     

Effect of dietary fish oil on milk yield, fatty acids content and serum metabolic profile in dairy cows

The aim of the study was to evaluate the effects of dietary unprotected fish oil on milk yield, fatty acids content and serum metabolic profile in dairy cows. Forty lactating Polish Holstein-Friesian cows were assigned to two groups. The cows were fed a control basal diet (C group), or a basal diet containing 2% addition of fish oil on mineral carrier (FOM group) during a 8-week period. Supplementing FOM diet of dairy cows had no significant effect on milk fat, milk protein, milk lactose concentration and somatic cells count, but increased the milk yield (36.5 kg/d), (p < 0.05) compared with the control cows (34.28 kg/d). We observed an increase (p < 0.05) in body condition scoring between C and FOM groups. Additionally, higher levels of non-esterified fatty acids and β-hydroxybutyrate acid were noticed in FOM group after 8 weeks of the experiment; however, these serum parameters still were in the reference range. Concentration of insulin was higher (30.40 μU/ml; p < 0.01) in the FOM group compared with the control group (14.03 μU/ml). In the FOM group, significant increase (p < 0.01) in long-chain fatty acids, mainly cis-9, trans-11 CLA and n-3 fatty acids (eicosapentaenoic and docosahexaenoic acids) was observed. The obtained results demonstrated that addition of fish oil to cows' diet could profitably modify the fatty acids in cow's milk.     

Influence of oils on the Taihe Silky Fowl production performances and fatty acids composition of the meat*

Focus on the enrichment of eggs and poultry meat with polyunsaturated fatty acids has increased given their important roles in the human health. The inclusion of polyunsaturated fatty acids (especially n‐3 fatty acids, n‐3 FA) is achieved by different biological methods. The objective of this study was to investigate the effects of inclusion of different oils into the feed on the production performances and fatty acids composition of the meat in Taihe Silky Fowl. A total of 80 fowls were selected at 8 weeks and randomly divided into four groups and fed with basal diet, basal diet + 4% fish oil, basal diet + 4% soybean oil and basal diet + 4% palm oil within 3 weeks respectively. The results showed that: the fowls fed with the diet inclusion of 4% fish oil had higher total gain, average daily gain, the second and the third week average daily gain than those in control group (p < 0.05). Also, inclusion of fish oil could improve the content of C22:5 n‐3 and C22:6 n‐3 polyunsaturated fatty acids in the meat significantly compared with the other three groups (p < 0.01). Meanwhile, C18:3 n‐3 and C18:4 n‐3 polyunsaturated fatty acids were also higher than in the other three groups (p < 0.05 and 0.01). Oils Supplementation could enhance C14:0 and C16:0 (p < 0.05) level, but they did not affect the total saturated fatty acids in the meat. Compared with the control group, fish oil inclusion could lower the C18:2 n‐6 level, higher the C18:3 n‐6, C22:4 n‐6 and C22:5 n‐6 polyunsaturated fatty acids in the meat (p < 0.05). Moreover, diets supplied with 4% fish oil reduced the total n‐6 polyunsaturated fatty acids level and enhanced the total n‐3 polyunsaturated fatty acids level in the meat, which resulted in that the ratio of n‐3/n‐6 was improved, and could meet the need of human body.