日粮添加亚麻油酸对断奶仔猪组织器官脂肪酸组成及脂肪酸代谢相关酶活力的影响

文章旨在研究在母猪日粮和断奶仔猪日粮中添加亚麻油酸对断奶仔猪组织器官脂肪酸组成及脂肪酸代谢相关酶活力的影响。选择妊娠110 d的母猪100头,随机分为2组,母猪分娩后对照组饲喂母猪基础日粮,试验组在基础日粮中添加1%的亚油酸。母猪分娩后,选择体重为(6.03±0.45)kg的25 d断奶仔猪600头,随机分为3组,每组5个重复,每个重复40头猪。对照组饲喂断奶仔猪基础日粮(饲喂对照组日粮母猪分娩的仔猪)、处理1组(饲喂对照组日粮母猪分娩的仔猪)和处理2组(饲喂亚麻油酸日粮母猪分娩的仔猪)分别在基础日粮中添加1%亚麻油酸。试验期62 d。结果显示:母猪和仔猪日粮都添加亚麻酸油及仅仔猪日粮添加亚麻酸油组较对照组显著提高了62 d仔猪皮下脂肪苹果酸脱氢酶的活力(P 0.05)。母猪和仔猪日粮中添加亚麻油酸显著影响了断奶仔猪25 d和62 d肝脏和皮下脂肪中脂肪酸的组成(P 0.05),其中母猪日粮添加亚麻油酸较对照组显著提高了62 d仔猪皮下脂肪C18:1n-9、C18:2n-6、单不饱和脂肪酸和肝脏中C16:1n-7、C18:2n-6、C18:3n-3、单不饱和脂肪酸和脂肪的含量(P 0.05)。结果表明:在本试验条件下,母猪日粮添加亚麻油酸可以改变乳和断奶仔猪肝脏中脂肪酸的组成,25 d断奶仔猪肝脏和皮下脂肪脂肪酸的组成取决于仔猪日粮中亚麻油酸的添加水平。     

饲粮中配合橡胶籽饼对蛋鸡蛋黄脂肪酸组成的影响

本试验通过在海兰褐蛋鸡饲粮中配合不同比例的橡胶籽饼,评价其对蛋黄脂肪酸组成及胆固醇含量的影响。选取72只25周龄的健康海兰褐蛋鸡,随机分成6个组,每组4个重复,每个重复3只鸡。对照组饲喂玉米-豆粕型基础饲粮,Ⅰ~Ⅴ组饲粮分别配合5.00%、10.00%、15.00%、20.00%和25.00%的橡胶籽饼。各组饲粮的营养水平一致。试验期6周。结果表明:饲粮中配合不同比例橡胶籽饼对蛋鸡蛋黄饱和脂肪酸(SFA)含量无显著影响(P0.05);但蛋黄亚油酸(LA)、α-亚麻酸(ALA)、二十碳五烯酸(EPA)和二十二碳六烯酸(DHA)含量随饲粮橡胶籽饼配合比例的增加呈增加趋势,且各试验组蛋黄DHA含量与对照组相比差异显著(P0.05);随饲粮橡胶籽饼配合比例的增加,蛋黄总多不饱和脂肪酸(PUFA)、n-6 PUFA和n-3 PUFA含量呈增加趋势,n-6/n-3 PUFA呈降低趋势;各试验组蛋黄胆固醇含量与对照组相比差异不显著(P0.05),但均低于对照组。由此可见,饲粮中配合一定比例的橡胶籽饼能够获得较低的n-6/n-3PUFA,达到提高蛋黄总PUFA、n-6 PUFA和n-3 PUFA含量的效果。     

妊娠后期及哺乳期日粮中添加不同形式的亚麻对母猪及其仔猪脂肪酸组成的影响

本试验旨在研究在妊娠后期及哺乳期日粮中分别添加亚麻籽、亚麻籽粉和亚麻籽油对母猪及仔猪脂肪酸组成的影响。试验选用60头经产约克夏×长白母猪。将其随机分往以下四个处理组:1)对照组,(CTL不添加亚麻,n=15);2)10%亚麻籽组(FS,n=16);3)6.5%亚麻粉组(FSM,n=14)和4)3.5%亚麻油组(FSO,n=15),试验日粮从妊娠第68d开始饲喂直到产后第21d,4个处理组日粮为等氮和等能量日粮。母猪分别于妊娠的第62d、110d及产后第2d、21d颈静脉采血,产后第3d、20d采集母乳,分析血浆和乳汁中脂肪酸组成,每窝屠宰1头仔猪测定胴体和脑组织脂肪酸组成。妊娠的第110d,与FSM组相比,FS和FSO组母猪血清中n-6/n-3脂肪酸比值降低(P0.001)、SFA(P0.05),含有更多的PUFA(P0.001)和n-3脂肪酸(P0.001)。产后第21d各处理组间血清MUFA存在差异(P0.05),产后第3d、21d,FS和FSO组乳汁n-3含量升高(P0.01)而n-6/n-3比降低(P0.001)。与FSM组比,FS和FSO组新生仔猪胴体和脑组织中n-3脂肪酸升高(P0.001)而n-6/n-3比降低(P0.01)。结果表明饲喂添加亚麻籽和亚麻油能显著提高母猪及其仔猪脂肪酸组成,而这取决于亚麻中油的组成,FSM组未获得与其他亚麻处理组相同的效果。     

产蛋鸡日粮亚麻油水平对蛋黄脂肪组成及脂质代谢的影响

选择54只50周龄健康海蓝褐壳蛋鸡,随机分成3组,每组6个重复,每个重复3只鸡,分别饲喂含0%、2%和4%亚麻油的日粮,研究不同亚麻油水平对蛋黄脂肪酸组成及脂质代谢的影响。结果表明:日粮亚麻油水平升高,肝脏和蛋黄中α-亚麻酸(ALA)、二十碳五烯酸(EPA)和二十二碳六烯酸(DHA)等n-3多不饱和脂肪酸(n-3PUFA)的含量显著增加(P0.05)。与0%亚麻油组比较,2%和4%亚麻油组蛋黄的ALA分别增加8.33倍和18.18倍,EPA含量分别增加7.75倍和4.00倍,DHA含量分别增加5.95%和9.19%。表明蛋黄沉积脂肪酸与日粮脂肪酸组成有强相关。日粮中亚麻油脂肪酸的组成可直接反映在鸡蛋蛋黄沉积的脂肪酸上,在日粮中添加亚麻油,可获得富含n-3PUFA鸡蛋。     

饲粮中添加膨化苜蓿草粉-亚麻籽对母猪初乳成分及母猪、仔猪血清脂质代谢指标和脂肪酸含量的影响

本试验旨在研究饲粮中添加膨化苜蓿草粉-亚麻籽对母猪初乳成分及母猪、仔猪血清脂质代谢指标和脂肪酸含量的影响。试验选用80头胎次、体况和预产期接近的长×大妊娠母猪,随机分为4组,每组4个重复,每个重复5头,单栏饲喂。对照组、试验Ⅰ组、试验Ⅱ组和试验Ⅲ组分别饲喂添加不同比例(0、5%、10%和15%)膨化苜蓿草粉-亚麻籽的试验饲粮。试验从母猪妊娠第83天开始,至哺乳第21天结束。结果表明:1)与对照组相比,试验Ⅰ组的初乳中乳糖含量有升高的趋势(P=0.090),试验Ⅱ组和试验Ⅲ组的初乳中乳蛋白含量显著升高(P<0.05),试验Ⅱ组的初乳中总固形物含量有升高的趋势(P=0.099)。2)与对照组相比,试验Ⅱ组的母猪血清中低密度脂蛋白胆固醇(LDL-C)含量有降低的趋势(P=0.089)。3)与对照组相比,试验Ⅱ组的仔猪血清中LDL-C含量显著降低(P<0.05),血清中总胆固醇(TC)含量有降低的趋势(P=0.081)。4)与对照组相比,试验Ⅰ组、试验Ⅱ组和试验Ⅲ组的母猪血清中亚油酸(LA)、n-6多不饱和脂肪酸(PUFA)含量和n-6多不饱和脂肪酸/n-3多不饱和脂肪酸(n-6 PUFA/n-3 PUFA)显著降低(P<0.05),血清中二十碳五烯酸(EPA)和二十二碳五烯酸(DPA)含量显著升高(P<0.05);试验Ⅱ组和试验Ⅲ组的血清中花生四烯酸(AA)和饱和脂肪酸(SFA)含量显著降低(P<0.05),血清中α-亚麻酸(ALA)、n-3多不饱和脂肪酸(n-3 PUFA)含量和不饱和脂肪酸/饱和脂肪酸(UFA/SFA)显著升高(P<0.05)。5)与对照组相比,试验Ⅰ组、试验Ⅱ组和试验Ⅲ组的仔猪血清中LA、AA、n-6 PUFA含量和n-6 PUFA/n-3 PUFA显著降低(P<0.05),血清中EPA含量显著升高(P<0.05);试验Ⅱ组的血清中二十二碳六烯酸(DHA)、DPA、单不饱和脂肪酸(MUFA)、PUFA、n-3 PUFA含量和UFA/SFA显著升高(P<0.05);试验Ⅱ组和试验Ⅲ组的血清中ALA含量显著升高(P<0.05),血清中SFA含量显著降低(P<0.05)。6)相关性分析显示,母猪血清中高密度脂蛋白胆固醇(HDL-C)含量与仔猪血清中TC和甘油三酯(TG)含量呈显著负相关(P<0.05),与仔猪血清中HDL-C含量呈显著正相关(P<0.05);母猪血清中LDL-C含量与仔猪血清中TC、TG和LDL-C含量呈显著正相关(P<0.05)。母猪血清中EPA、DHA、DPA、ALA和n-3 PUFA含量与仔猪血清中EPA、DHA、DPA、ALA、UFA、n-3 PUFA含量和UFA/SFA呈显著正相关(P<0.05),与仔猪血清中n-6 PUFA/n-3 PUFA呈显著负相关(P<0.05)。综上所述,饲粮中添加膨化苜蓿草粉-亚麻籽可以提高母猪初乳品质,改善母猪血清脂质代谢,增加母猪血清中n-3 PUFA含量,从而对仔猪的血清脂质代谢和脂肪酸组成也产生积极影响,有利于仔猪的机体健康。     

日粮添加鱼粉和n-3多不饱和脂肪酸对奶牛泌乳早期卵巢和子宫机能的影响

本试验旨在研究日粮中添加鱼粉和n-3多不饱和脂肪酸对奶牛泌乳早期卵巢功能和子宫反应的影响。从产奶第5~50 d,给奶牛饲喂等氮、等能、等脂肪日粮,其中处理分别为0%(对照组)以及1.25%、2.5%、5%的鱼粉和2.3%的鱼油脂肪酸钙盐。本试验通过检测血浆中雌二醇和孕酮含量的变化来反映卵泡的动态变化。从产奶第23 d开始,人工诱导奶牛进入同步排卵周期。在排卵后15 d(产奶第49 d)给奶牛注射垂体后叶素,并同时采集血样检测PGF2α含量。活体收集子宫内膜组织进行脂肪酸和环加氧酶蛋白-2(COX-2)蛋白含量的分析。试验结果表明:各日粮处理间卵泡活性、血浆雌二醇和孕酮浓度变化不大。日粮添加鱼粉和鱼油脂肪酸钙盐后子宫内膜脂肪酸组成中EPA(C20∶5,n-3)和DHA(C22∶6,n-3)含量大约上升了3倍,同时也伴随着子宫内膜组织中共轭亚油酸(C18∶2 cis-9,trans-11)含量的上升;与之相反,在5%鱼粉处理组子宫内膜组织中花生四烯酸(C20∶4,n-6)含量却降低。随着给奶牛注射垂体后叶素,各日粮处理间血浆PGF2α含量变化并不明显,并且内膜组织COX-2蛋白含量变化也不显著。因此通过本试验结果表明:在奶牛泌乳初期日粮中添加鱼粉或n-3多不饱和脂肪酸能显著增加子宫内膜组织n-3脂肪酸浓度,但当给奶牛注射垂体后叶素时并不能显著改变子宫内膜组织中COX-2或血浆中PGF2α的含量。     

日粮中脂肪酸对羊牛猪肉中长链多不饱和脂肪酸和共轭亚油酸的影响

随着消费者健康意识的提高,越来越多的研究关注提高家养动物肉产品中多不饱和脂肪酸(PUFA)含量,尤其是n-3长链脂肪酸和共轭亚油酸(CLA)在羊、牛、猪肉肌内脂中的含量。研究结果表明通过添加鱼油或鱼粉能提高动物肉中n-3长链脂肪酸含量。富含亚麻油酸(LNA)的日粮能提高肉中LNA、二十碳五烯酸(EPA)和二十二碳五烯酸(DPA)水平,但大部分对肌肉中二十二碳六烯酸(DHA)水平没有影响。然而,在日粮中添加鱼油或鱼粉大部分能提高动物肌肉中DHA含量。大部分研究中提高n-3脂肪酸含量的同时n-6脂肪酸含量下降,这主要归因于试验组日粮中n-6脂肪酸降低。这样刚好可以使肉中两者比例更合理,但对多不饱和脂肪酸与饱和脂肪酸比例没什么影响。饲喂反刍动物富含n-3脂肪酸日粮(亚麻籽或加草料)、鱼油或富含LA的浓缩料可提高肌肉中c9t11CLA含量。牛肉、羊肉中c9t11CLA在总脂中含量介于0.2~1.0 g/100 g,不随营养因素提高到更高。相对应的,在单胃动物日粮中添加混合CLA油则显著提高CLA含量。     

n-3脂肪酸对肉鸡生产性能、器官指数及腿肌脂肪酸含量的影响

本研究旨在通过给肉仔鸡日粮中添加富含n-3脂肪酸的海藻粉,评价其对肉仔鸡生长性能、器官指数和腿肌脂肪酸组成的影响。试验共用480只肉仔鸡,随机分为3个处理,每个处理8个重复,每个重复1笼,每笼20只。基础日粮为玉米-豆粕型,对照组和试验组的日粮组成如下:(1)对照组(基础日粮);(2)试验日粮1(基础日粮+0.10%富含n-3脂肪酸的海藻粉);(3)试验日粮2(基础日粮+0.20%富含n-3脂肪酸的海藻粉)。试验结果表明,各组的生长性能和器官指数无显著差异。然而,海藻粉组饱和脂肪酸(SFA)和单不饱和脂肪酸(MUFA)的含量均显著降低(P0.05),而多不饱和脂肪酸(PUFA)显著增加(P0.05)。总之,日粮中添加富含n-3脂肪酸的海藻粉能使腿肌中PUFA含量增加,SFA和MUFA含量减少。     

混合油脂对清远麻鸡胸肌脂肪酸组成的影响及其代谢组机制研究

本试验旨在研究单一和混合油脂日粮对肉鸡生长性能和胸肌脂肪酸组成的影响,并利用代谢组学技术探究日粮油脂干预后胸肌脂肪酸组成发生变化的代谢机制,为调控肉鸡脂肪酸组成的研究提供新思路。选取1日龄慢速型清远麻母鸡480只,随机分为2组(每组6个重复,每个重复40只),对照组(CON)饲喂大豆油日粮,试验组(BOF)饲喂等量的混合油脂(大豆油∶猪油∶鱼油∶椰子油=1.0∶1.0∶0.5∶0.5)日粮,试验期127 d。结果表明,与对照组相比,混合油脂日粮对肉鸡平均日增重没有显著影响(P0.05),但显著降低了肉鸡的平均日采食量和料重比(P0.05);显著增加了肉鸡胸肌中月桂酸(C12∶0)、肉豆蔻酸(C14∶0)、油酸(C18∶1n-9)、二十碳五烯酸(EPA,C20∶5n-3)和二十二碳六烯酸(DHA,C22∶6n-3)的比例,显著降低了亚油酸(C18∶2n-6)比例(P0.05)。利用液相色谱-质谱联用(LC-MS)技术,在试验鸡胸肌中共筛选到110种差异代谢物(变量权重值(VIP)1,P0.05),其中63种差异物质被注释,主要是磷脂代谢物,包括磷脂酰胆碱(PC)、磷脂酰丝氨酸(PS)和磷脂酰乙醇胺(PE)等。此外,与对照组相比,混合油脂组显著增加了胸肌中谷胱甘肽和肌肽含量(P0.05)。代谢通路富集分析表明,α-亚麻酸代谢、花生四烯酸代谢、亚油酸代谢和甘油磷酸代谢等脂质代谢通路发生显著改变(P0.05)。综上,混合油脂日粮相较于大豆油日粮提高了肉鸡的饲料转化效率,促进了胸肌组织中DHA和EPA的沉积;日粮油脂干预后肉鸡胸肌中磷脂代谢物、氧化稳定性代谢物和脂类代谢途径发生显著改变。本研究鉴定出的差异代谢物和差异代谢通路可为调控肉鸡脂肪酸组成的研究提供参考。     

饲粮中添加微藻DHA和ALA对蛋黄脂肪酸构成及蛋黄胆固醇、三酰甘油的影响

试验旨在研究饲粮中添加微藻二十二碳六烯酸(DHA)和α-亚麻酸(ALA)对蛋黄脂肪酸成分以及蛋黄胆固醇、甘油三酯的影响。方法:选取300日龄海兰褐蛋鸡576只,随机分为3个处理,每个处理3个重复,每重复64只鸡。对照组饲喂基础饲粮,试验组添加0.2%DHA和0.3%ALA,试验期42 d。结果表明:添加DHA和ALA的鸡蛋,多不饱和脂肪酸(PUFA)的含量均有显著提高(P0.05);添加DHA比添加ALA更能显著增加蛋黄中的二十二碳六烯酸(P0.05),更具降低胆固醇等作用。2个添加组均能显著增加n-3多不饱和脂肪酸(n-3PUFA)的含量(P0.05),并且添加DHA或ALA均能降低n-6/n-3的比值;添加DHA和ALA都可以显著降低蛋黄中的总胆固醇(TC)和总三酰甘油(TG)值(P0.05);添加DHA能更有效的降低血清TG。     

Dietary n-3 and n-6 fatty acids alter avian glucose metabolism

(1) This investigation studied the effects of dietary saturated and polyunsaturated fatty acids (PUFAs) from the n-3 and n-6 series on insulin action and glucose uptake in broiler chickens. (2) One-day-old male chicks were fed on a commercial starter diet for 3 weeks, randomly divided into three groups (n = 6) and fed ad libitum on isonitrogenous experimental diets of equal energy density for a further 6 weeks. The diets contained 20.8 g/100 g protein and 80 g/kg of either edible tallow, fish oil or sunflower oil, giving diets high in saturated fatty acids, n-S PUFAs or n-6 PUFAs, respectively. (3) Jugular catheterisation was performed under general anaesthesia during week 4 of the dietary treatments and the birds given 7 d post-surgery to recover. To estimate insulin action, a bolus glucose infusion (1 g/kg) was given to each chicken and sequential blood samples taken over a one-hour period. To estimate the disappearance rate of glucose from the plasma and its incorporation into tissues, 2-deoxy-D-3H glucose (2DG-3H glucose) was infused into each chicken (50 microCi) 2 d later. (4) Although there were no significant differences in glucose clearance rate following the glucose infusion, the maximal insulin release in response to the glucose infusion was higher in the tallow group than in either the n-3 or n-6 PUFA dietary groups. There were no significant differences in the clearance rate of 2DG-3H glucose. Labelled glucose incorporation into the breast muscle was greater in birds given fish oil than in birds given tallow and significantly greater than in birds given sunflower oil. (5) The data suggest that the type of dietary fat can influence glucose metabolism and that this change in glucose utilisation may alter the energy metabolism of the broiler.     

日粮n-3多不饱和脂肪酸对母猪繁殖性能的影响

n-3多不饱和脂肪酸作为一种重要的营养物质,能影响家畜繁殖性能。本文主要从n-3多不饱和脂肪酸作用机理、使用效果等方面阐述n-3多不饱和脂肪酸对母猪繁殖性能的影响。     

Effect of diets containing n-3 fatty acids on muscle long-chain n-3 fatty acid content in lambs fed low- and medium-quality roughage diets

In two experiments, each with 32 cross-bred ([Merino x Border Leicester] x Poll Dorset) wether lambs (26 to 33 kg weight range), animals were randomly assigned to one of four treatments. A mixture of lucerne chaff:oaten chaff was used as a basal diet, offered in different ratios. Animals were allowed to consume on a free-access basis in Exp. 1 or 90% of ad libitum intake in Exp. 2 in order to provide a low- (6.5 MJ ME/d) and medium- (9.5 MJ ME/d) quality basal diet, respectively. Isoenergetic amounts of lipid supplements, fish meal (80 g DM), canola meal (84 g DM), and soy meal (75 g DM) were tested in Exp. 1. In Exp. 2, fish meal (9% DM), unprotected rapeseed (7% DM), and protected canola seed (6% DM) were fed as supplements. At the end of 53-d (Exp. 1) or 46-d (Exp. 2) experimental periods, lambs were slaughtered at a commercial abattoir and at 24 h postmortem longissimus thoracis (LT) muscle was collected for the analysis of fatty acid (FA) composition of structural phospholipid and storage triglyceride fractions. Fish meal diet increased LT muscle long-chain n-3 FA content by 27% (P < 0.02) in Exp. 1 and 30% (P < 0.001) in Exp. 2 compared with lambs fed the basal diet, but fish meal decreased (P < 0.01) the n-6 FA content only in Exp. 1. Soy meal and protected canola seed diets increased (P < 0.01) LT muscle n-6 FA content but did not affect long-chain n-3 FA content. Longissimus thoracis muscle long-chain n-3 FA were mainly deposited in structural phospholipid, rather than in storage triglyceride. In both Exp. 1 and Exp. 2, the ratio of n-6:n-3 FA in LT muscle was lowest (P < 0.01) in lambs fed fish meal supplement compared with all other treatments. Protected canola seed diet increased the ratio of n-6:n-3 FA (P < 0.01) and PUFA:saturated fatty acid (P < 0.03) content from those animals fed the basal, fish meal, and unprotected rapeseed diets in Exp. 2. This was due to an increase in muscle n-6 FA content, mainly linoleic acid, of both phospholipid (P < 0.001) and triglyceride (P < 0.01) fractions and not to an increase in muscle n-3 FA content. The results indicate that by feeding fish meal supplement, the essential n-3 FA can be increased while lowering the ratio of n-6:n-3 content in lamb meat to an extent that could affect nutritional value, attractiveness, and the economic value of meat.     

Dietary (n-3) fatty acids from menhaden fish oil alter plasma fatty acids and leukotriene B synthesis in healthy horses

The study objective was to determine the effect of feeding corn oil or fish oil to horses on plasma fatty acid profiles and leukotriene B (LTB) synthesis by stimulated peripheral blood neutrophils. Two groups of horses (n = 5) were randomly assigned to diets supplemented with either 3.0% (by weight) corn oil or fish oil for a period of 14 weeks. The ratio of (n-6) to (n-3) fatty acids in oil supplements was 68.1:1 for corn oil and 0.12:1 for fish oil. Production of LTB4 and LTB, by peripheral blood neutrophils stimulated with calcium ionophore A23187 and plasma cholesterol, triacylglycerol, and alpha-tocopherol concentrations were measured. At 12 weeks, horses fed fish oil had increased plasma concentrations of eicosapentaenoic acid (27-fold; 8.5 versus 0.3 g/100 g fatty acids; P < .0001), docosahexaenoic acid (34-fold; 5.1 versus 0.1 g/100 g fatty acids; P < .0001), and arachidonic acid (8.3-fold; 4.1 versus 0.5 g/100 g fatty acids; P < .0001) compared with horses fed corn oil. Neutrophils from horses fed fish oil produced 78-fold (P = .01) more LTB5 and 9.5-fold (P = .003) more LTB4 compared with predietary levels, and 17.6-fold (P = .01) and 3.3-fold (P = .02), respectively, more than horses fed corn oil, and the ratio of LTB5 to LTB4 concentrations was 4.0-fold (P = .002) higher in horses fed fish oil. This study suggests that dietary polyunsaturated fatty acids modulate the leukotriene inflammatory response of horses. If the ratio of LTB5 to LTB4 concentrations is important in determining how inflammatory processes are mediated, then fish oil supplementation may have value in treatment of equine inflammatory diseases.     

Plasma and skin concentrations of polyunsaturated fatty acids before and after supplementation with n-3 fatty acids in dogs with atopic dermatitis

OBJECTIVE: To determine essential fatty acid concentrations in plasma and tissue before and after supplementation with n-3 fatty acids in dogs with atopic dermatitis. ANIMALS: 30 dogs with atopic dermatitis. PROCEDURE: Dogs received supplemental flaxseed oil (200 mg/kg/d), eicosapentaenoic acid (EPA; 50 mg/kg/d)-docosahexaenoic acid (DHA; 35 mg/kg/d), or mineral oil as a placebo in a double-blind, placebo-controlled, randomized trial. Clinical scores and plasma and cutaneous concentrations of linoleic acid, arachidonic acid, alpha-linolenic acid (alpha-LLA), EPA, DHA, prostaglandin E2, and leukotriene B4 were determined. RESULTS: Total plasma concentrations of alpha-LLA and EPA increased and those of arachidonic acid decreased significantly with administration of EPA-DHA, and concentrations of alpha-LLA increased with flaxseed oil supplementation; nevertheless, there was no significant change in the concentrations of these fatty acids or eicosanoids in the skin. There was no correlation between clinical scores and plasma or cutaneous concentrations for any of the measured fatty acids or eicosanoids. CONCLUSION AND CLINICAL RELEVANCE: Results indicated that at the dose used, neither the concentrations of fatty acids in skin or plasma nor a decrease in the production of inflammatory eicosanoids was a major factor involved in the mechanism of action in dogs with atopy that responded to fatty acid supplementation.     

Fatty acid patterns of dog erythrocyte membranes after feeding of a fish-oil based DHA-rich supplement with a base diet low in n-3 fatty acids versus a diet containing added n-3 fatty acids

Background

In dogs, increasing the tissue n-3 fatty acid (FA) content is associated with potential benefit in some medical conditions, e.g. atopic dermatitis, cancer or heart disease. Therefore effectively and conveniently increasing tissue n-3 FA levels in dogs is of interest. Incorporation of dietary n-3 FA into cell membranes may be studied by FA analysis of erythrocyte membranes (EM), because of the correlation of its FA composition with the FA composition of other cells. Aim of the study was to determine whether an n-3 FA additive added to a control diet is as effective in increasing EM n-3 FA content as feeding an n-3 FA enriched diet. Furthermore the time course of the incorporation of dietary n-3 FA into canine EM was investigated.

Methods

Thirty dogs were randomly divided into three dietary groups with ten dogs per group. CONT got a dry dog food diet which did not contain EPA or DHA. FO got a dry dog food diet with a high EPA and DHA content. ADD got the CONT diet combined with an n-3 FA additive rich in DHA and EPA. After a feeding period of 12 weeks the additive was discontinued in ADD and these dogs were fed CONT diet for another four weeks to observe washout effects. Erythrocyte lipids were extracted from venous blood samples and their FA composition was determined by gas chromatography. The Mann-Whitney-U-test was used to detect significant differences between the different groups and time points.

Results

After one week the proportions of n-3 FA, DHA and EPA were already significantly increased in ADD and FO, apparently reaching a plateau within eight weeks. In our study DHA and not EPA was preferably incorporated into the EM. After discontinuing the administration of the additive in ADD, the n-3 FA values declined slowly without reaching baseline levels within four weeks.

Conclusions

In dogs, an increase of dietary n-3 FA content leads to a rapid inclusion of n-3 FA into EM, regardless of whether the n-3 FA are offered as an enriched diet or as a normal diet supplemented with an n-3 FA additive.     

n-3多不饱和脂肪酸强化鸡蛋育鳙鱼苗效果研究

鸡蛋因营养全面均衡,可制成微粒来培育鱼苗,以弥补高密度养殖鱼苗时天然饵料的不足。近20年来,人们愈来愈重视饲料中n-3多不饱和脂肪酸(PUFA)对鱼类的作用,研究开发的n-3PUFA强化鸡蛋是用含有一定量n-3PUFA的原料如鱼油、亚麻籽、红花油等饲喂蛋鸡,经鸡蛋富集而成。目前,该技术     

Effects of dietary n-6 and n-3 fatty acids and vitamin E on the immune response of healthy geriatric dogs

OBJECTIVE: To determine the effect of dietary n-6 to n-3 fatty acid ratios and alpha-tocopheryl acetate concentration on immune functions andT cell subpopulations in healthy dogs. ANIMALS: Thirty-two 7- to 10-year old female Beagles. PROCEDURE: For 17 weeks, dogs were fed food that contained low (1.4:1) or high (40:1) ratios of n-6 to n-3 fatty acids in combination with 3 concentrations of all rac-alpha-tocopheryl acetate (low, 17 mg/kg of food; medium, 101 mg/kg; high, 447 mg/kg). Dogs were inoculated twice with a keyhole limpet hemocyanin suspension at 13 and 15 weeks. RESULTS: After 12 weeks, dogs consuming low concentrations of alpha-tocopheryl acetate had lower percentages of CD8+ T cells, compared with dogs consuming medium or high alpha-tocopheryl acetate concentrations. Also, dogs consuming low alpha-tocopheryl acetate concentrations had higher CD4+ to CD8+ T cell ratios. On day 4 of week 15, the percentage of CD8+ T cells was highest in dogs fed medium concentrations of alpha-tocopheryl acetate, compared with other dogs; however, the CD4+ to CD8+ T cell ratio was higher only in dogs fed low concentrations of alpha-tocopheryl acetate with high concentrations of n-3 fatty acids. Dogs consuming low concentrations of n-3 fatty acids with medium concentrations of alpha-tocopheryl acetate had the largest delayed-type hypersensitivity (DTH) skin test response. CONCLUSIONS AND CLINICAL RELEVANCE: An optimum amount of dietary alpha-tocopheryl acetate concentration, regardless of the dietary n-6 to n-3 fatty acid ratio, stimulates the CD8+ T cell population. Effects of an optimum amount of dietary alpha-tocopheryl acetate concentration on the DTH response are blunted by dietary n-3 fatty acids.     

Treatment of Culicoides hypersensitive horses with high-dose n-3 fatty acids: a double-blinded crossover study

In this double-blinded crossover study the clinical efficacy of high dose α-linolenic acid (linseed oil) for the treatment of Culicoides spp. hypersensitivity was evaluated. Seventeen privately owned horses from north Florida, USA completed the 18-week study. Criteria for inclusion included negative dermatophyte cultures, negative skin scrapes, failure to respond to ivermectin treatment, compatible clinical signs, positive skin test to Culicoides spp.antigen and a history of seasonal pruritus consistent with Culicoides spp. hypersensitivity. Horses were randomized and each horse's feed was supplemented with 200 mL of linseed oil (n-3 source) or 200 mL of corn oil (n-6 source) per day for a 6-week period. After a 6-week washout period, each horse was crossed over to the other supplement for an additional 6 weeks. Horses were evaluated every 3 weeks. The level of pruritus was determined by counting pruritic acts in a 30-min period. Total lesional surface area was determined by computerized evaluation of scanned photographs and documented physical examination findings. There was no significant change in level of pruritus observed between the groups ( P  = 0.89). Additionally, lesional surface area was not significantly different between the groups ( P  = 0.06). However, most owners stated that horses improved while supplemented with linseed oil.     

Platelet function in dogs treated for lymphoma and hemangiosarcoma and supplemented with dietary n-3 fatty acids

A prospective randomized, double-blind clinical trial was performed to test the hypothesis that dogs with malignancies that are supplemented with n-3 fatty acids do not have clinical or laboratory evidence of coagulation disorders or altered platelet function when compared with unsupplemented dogs with similar malignancies. Thirteen dogs with hemangiosarcoma and 66 dogs with lymphoma were evaluated. Coagulation status of the dogs with lymphoma and hemangiosarcoma was evaluated with prothrombin time, partial thromboplastin time, platelet count, and in vitro platelet aggregometry using the whole-blood method. These tests were performed at 5 time points: before beginning the diet (week 0), at weeks 3, 15, and 21, and at 1 year or when progressive disease was evident. Alterations in platelet function in dogs receiving a diet supplemented with dietary n-3 fatty acids were not identified when compared to dogs fed a control diet. Dietary n-3 fatty acid supplementation using this dosage and ratio in dogs with lymphoma or hemangiosarcoma did not induce clinically significant hemorrhage in these animals. Therefore, supplementation with n-3 fatty acids did not result in clinical or laboratory evidence relating to uncontrolled hemorrhage in these dogs.