太湖鹅屠宰性能研究

对70日龄太湖鹅屠宰性能进行测定,并对相关参数进行相关性分析.结果表明.太湖鹅平均屠宰率、全净膛率、半净膛率、胸肌率、腿肌率分别为87.84%、69.66%、78.31%、11.35%、18.74%,半净膛率、胸肌率公母间差异极显著(P<0.01),全净膛率公母间差异显著(P<0.05):屠宰性能各指标间存在高等或中等强度相关.     

饲粮中n-6/n-3多不饱和脂肪酸比值对肉鹅生长性能、屠宰性能、血清脂质指标、肠道组织形态和胸肌脂肪酸组成的影响

试验旨在探究饲粮中n-6/n-3多不饱和脂肪酸（PUFA）比值对肉鹅生长性能、屠宰性能、血清脂质指标、肠道组织形态和胸肌脂肪酸组成的影响。选取120只体重为（1.0±0.1） kg的32日龄肉鹅（三花鹅），随机分成3组，每组5个重复，每个重复8只。Ⅰ组、Ⅱ组和Ⅲ组饲粮中n-6/n-3 PUFA比值分别为1∶1、6∶1、12∶1。试验期60 d。结果表明：1）饲粮中n-6/n-3 PUFA比值对肉鹅的生长性能无显著影响（P>0.05）。2）Ⅱ组的腹脂率显著低于其他2组（P<0.05）。3）Ⅱ组的血清低密度脂蛋白胆固醇（LDL-C）含量显著低于其他2组（P<0.05）。4）Ⅱ组的十二指肠绒毛高度显著高于Ⅰ组（P<0.05），Ⅱ组的回肠隐窝深度显著低于其他2组（P<0.05），Ⅱ组的回肠绒毛高度/隐窝深度显著高于其他2组（P<0.05）。5）Ⅱ组的胸肌辛酸、γ-亚麻酸、α-亚麻酸、二十碳六烯酸和n-3 PUFA含量显著高于其他2组（P<0.05）。由此可见，饲粮中n-6/n-3比值为6∶1时，肉鹅的腹脂率、血清LDL-C含量和回肠隐窝深度最低，十二指...     

酸化剂在肉鹅养殖中的应用效果评价

为探究酸化剂在水禽养殖中的应用效果,试验选取同一日龄、体重接近的健康扬州鹅公鹅120只,随机分为2组(6个重复,每个重复10只),分别为对照组和试验组,对照组饲喂基础日粮,试验组饲喂添加酸化剂的日粮(每千克基础日粮添加2 g复合酸化剂)。试验期70 d,测定扬州鹅的生长性能、屠宰性能和肌肉品质等指标。结果表明:(1)酸化剂对扬州鹅生长性能的影响较小,但有提高饲料报酬的趋势;(2)酸化剂可改善扬州鹅屠宰性能的各项指标,提高屠宰率、全净膛率、半净膛率、胸肌率和腿肌率,降低腹脂率;(3)酸化剂可显著提高胸肌水分、蛋白含量,而降低脂肪含量(P0.05),显著降低腿肌的水分、蛋白、剪切力和pH24h(P0.05),显著提高胶原和脂肪含量(P0.05)。     

日粮能量水平对扬州鹅屠宰性能和生化指标的影响

选用42日龄的扬州鹅200只,随机分成4组,每组5个重复,每个重复10只,公母各半。日粮能量水平分别为:Ⅰ组10.11 MJ/kg,Ⅱ组11.19MJ/kg,Ⅲ组12.37MJ/kg,Ⅳ组13.45MJ/kg,研究不同能量水平对42～56日龄扬州鹅屠宰性能和生化指标的影响。结果表明:日粮能量水平对56日龄扬州鹅的全净膛率、半净膛率、胸肌率、腿肌率、腿脂率、皮下脂肪厚和肌间脂肪宽度的影响差异不显著(P0.05),显著影响屠宰率和腹脂率(P0.05);日粮能量水平对血清胆固醇、低密度脂蛋白、谷草转氨酶、谷丙转氨酶、总蛋白和尿酸的含量影响差异不显著(P0.05),随着能量水平的升高,血清高密度脂蛋白显著增加(P0.05),而甘油三酯、极低密度脂蛋白和白蛋白显著下降(P0.05)。综上所述,日粮能量水平对42～56日龄扬州鹅屠宰率和腹脂率有显著的影响,并对血液生化指标有一定影响。     

盐津乌骨鸡屠宰性能与肉品质的相关性分析

为研究盐津乌骨鸡的肉用性能,探讨盐津乌骨鸡屠宰性能与肉品质的关系,试验测定了150日龄盐津乌骨鸡的屠宰性能、肉品质特性,并对屠宰性能与肉品质的相关性进行分析。结果:盐津乌骨鸡公鸡的活重、屠体重、半净膛、全净膛、半净膛率、全净膛率、胸肌重、腿肌重、胸肌率、腿肌率均高于母鸡,且半净膛率、全净膛率、腿肌重、腿肌率均极显著高于母鸡(P0.01),半净膛重与全净膛重显著高于母鸡(P0.05)。相同性别不同部位,公母鸡胸肌pH_(45min)、pH_(24h)、剪切力均极显著高于腿肌(P0.01);不同性别相同部位,母鸡胸肌与腿肌的A值均极显著高于公鸡(P0.01),但公鸡腿肌的失水率显著高于母鸡腿肌(P0.05)。腿肌重与剪切力间差异极显著(P0.01),且半净膛、全净膛与剪切力呈显著正相关关系(P0.05)。     

日粮能量和蛋白质水平对5～10周龄仔鹅生产性能的影响

选用4周龄扬州鹅180只,以能量和蛋白质为试验因子,采用2因素3水平设计,研究日粮能量和蛋白质水平对生长期扬州鹅生产性能的影响。研究结果表明:①10周龄体重和日增重各组间差异不显著(P>0.05),屠宰指标间无明显规律。②对体重、日增重、屠宰率和腿肌率的影响,均是互作>能量>蛋白质,其中互作和能量对腿肌率的影响极显著(P<0.01);对半净膛率和全净膛率的影响,均是能量>互作>蛋白质,且影响均不显著(P>0.05);对胸肌率的影响,是能量>蛋白质>互作,且影响不显著(P>0.05)。③第7组(低能高蛋白组)在生长性能和经济效益方面均较佳。因此,推荐5￣10周龄仔鹅日粮能量、蛋白质水平分别为10.50MJ/kg、17%。     

性别对磐石灰鹅体尺、屠宰性能及二者之间相关性的影响

为了研究性别对磐石灰鹅体尺、屠宰性能及二者间相关性的影响,试验选择健康的10周龄磐石灰鹅40只(公母各半)为研究对象,测定公母鹅的体尺指标(包括体斜长、龙骨长、胫围、颈长、半潜水长、胸深、胸宽、髋骨宽、胫长)和屠宰性能指标(包括活体重、屠体重、半净膛重、全净膛重、胸肌重、腿肌重、屠宰率、半净膛率、全净膛率、胸肌率和腿肌率),分析公母鹅在体尺和屠宰性能及二者之间相关性方面的差异。结果表明：磐石灰鹅公鹅半潜水长极显著高于母鹅(P<0.01),龙骨长显著高于母鹅(P<0.05),其他体尺指标公母鹅之间均差异不显著(P>0.05),但公鹅体斜长、胸宽、髋骨宽、胫长、颈长均高于母鹅。公母鹅屠宰率分别为92.22%和92.84%,全净膛率分别为74.95%和70.72%,公鹅的全净膛重和全净膛率均显著高于母鹅(P<0.05),公鹅胸肌率极显著低于母鹅(P<0.01),公鹅腿肌重极显著高于母鹅(P<0.01),其他屠宰性能指标公母鹅之间均差异不显著(P>0.05)。公鹅半潜水长与体斜长之间呈极显著正相关(P<0.01),体斜长与胫长、半潜水长与龙骨长和...     

吐鲁番斗鸡肉用性能研究

为了研究吐鲁番斗鸡的肉用性能,给吐鲁番斗鸡的保种选育提供参考依据,对8月龄吐鲁番斗鸡的屠宰性能和肉用性能进行了测定。结果表明,吐鲁番斗鸡产肉性能优良,平均体重达2 522.01g,平均屠宰率、半净膛率、全净膛率、胸肌率、腿肌率分别为92.11%、84.69%、71.05%、18.57%、22.83%。公鸡的活重、屠体重、半净膛重、全净膛重、胸肌重、腿肌重都极显著高于母鸡,但母鸡的腹脂重极显著高于公鸡。母鸡的屠宰率、胸肌率和腹脂率极显著高于公鸡,公鸡的腿肌率极显著高于母鸡。     

文昌鸡的屠宰性能及性状间的相关性分析

为了解海南省地方品种文昌鸡的肉用性能特点,对文昌鸡、仙居鸡、海兰褐蛋鸡、岭南黄肉鸡和艾维茵肉仔鸡在各自上市日龄进行了屠宰测定.文昌鸡的活重、屠体重、半净膛重、全净膛重、腿肌重与海兰褐相当,显著低于其它3个鸡种;屠宰率、半净膛率显著高于仙居鸡和海兰褐而低于艾维茵;胸肌率显著低于海兰褐和艾维茵;腿肌率显著高于岭南黄和艾维茵.文昌鸡的皮下脂肪厚、肌间脂肪宽和腹脂率在5个鸡种中最高;胫长、胸骨长最短.文昌鸡的胸骨长与活重、屠体重、半净膛重、全净膛重、胸肌重、腿肌重、翅重的相关系数在0.58～0.76之间;胫长与活重、屠体重、半净膛重、全净膛重、胸肌重、翅重的相关系数在0.49～0.68之间.     

朝鲜鹌鹑屠宰性能研究

试验对38日龄朝鲜鹌鹑屠宰性能进行测定,并对相关指标进行相关性分析。结果表明:朝鲜鹌鹑平均屠宰率、半净膛率、全净膛率、腿肌率和胸肌率分别为89.64%、79.52%、62.65%、19.70%和31.10%;母鹑的活重、屠体重、半净膛重、全净膛重、腿肌重和胸肌重极显著高于公鹑(P0.01),半净膛率和胸肌率显著高于公鹌鹑(P0.05);屠宰性能各指标间存在着高等强度相关。     

不同n-6/n-3多不饱和脂肪酸比值对断奶仔猪生长性能和免疫反应的影响

为探讨不同n-6/n-3多不饱和脂肪酸(PUFA)比值对断奶仔猪生长性能和免疫功能的影响,试验选用96头21日龄断奶、平均体重5.5 kg的杜×长×大仔猪,按单因子试验设计随机分为4个处理,分别饲喂n-6/n-3PUFA比值为2.5、5、10和20的日粮。试验期21 d。结果表明:在试验的0~7 d,采食n-6/n-3 PUFA比值为10日粮的仔猪日增重显著高于采食n-6/n-3 PUFA比值为2.5和20日粮的仔猪(P<0.05),同时,日粮n-6/n-3PUFA比值为10可显著改善0~7 d和0~21 d饲料转化效率(P<0.05);3种炎性细胞因子IL-1βI、L-6、TNF-α随着n-6/n-3 PUFA比值的增加而呈二次曲线变化趋势(P<0.05)。综合断奶仔猪生产性能和炎性细胞因子指标可以得出,断奶仔猪日粮中最佳的n-6/n-3PUFA比值为10。     

Reproductive Performance of Broiler Breeder Hens Fed n-3 Fatty Acid-rich Fish Oil

Abstract

The objective of the study was to investigate the effects of oil sources in the diet on milk yield, milk composition, and fatty acid (FA) profiles in mid-lactating dairy cows. Forty-eight Chinese Holstein dairy cows averaging 150 days in milk (DIM) at the start of the experiment (body weight = 596±19 kg; milk yield = 29.7±3.00 kg/d) were used in a completely randomized block design. The animals were assigned into four dietary treatments according to DIM and milk yield, and supplemented with no oil (control), 2% flaxseed oil (FSO), 2% soybean oil (SBO), and 2% oil from extruded soybeans (ESB). The experiment lasted nine weeks including the first week for adaptation. Milk yields, milk compositions (fat, protein, and lactose), and milk FA profiles were measured. Daily milk yield from cows fed with FSO, SBO, and ESB were higher than milk yield of the control cows (27.0, 27.0, and 26.5 vs. 25.4 kg/d). Milk fat percentage of the control cows was greater than those cows fed with oil-supplemented diets. However, increasing dietary fat content resulted with no change in fat-corrected milk yield. The FA profile of milk was changed by fat supplementation. Feeding oil reduced the proportion of both short-chain (C_8:0 to C_12:0) and medium-chain (C_14:0 to C_16:1) FAs, and increased the proportion of long-chain (≥C_18:0) FAs in milk fat. Cis-9, trans-11 conjugated linoleic acid (CLA) in milk fat was increased from 0.38% for the control to 0.79, 1.51, and 1.56% of fat for the cows supplemented with FSO, SBO, and ESB, respectively. Feeding oils rich in linoleic acid (SBO and ESB) was more effective in enhancing cis-9, trans-11 CLA in milk fat than oils containing linolenic acid (FSO). There was a linear relationship between transvaccenic acid and cis-9, trans-11 CLA content in milk. Overall, feeding the FSO, SBO, and ESB diets increased monounsaturated and polyunsaturated fatty acids and decreased the saturated fatty acid in milk fat.     

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.     

饲粮n-6/n-3多不饱和脂肪酸比值对冬毛期北极狐生长性能及肝脏脂肪酸代谢相关蛋白基因表达的影响

本试验旨在研究饲粮n-6/n-3多不饱和脂肪酸(PUFA)比值对冬毛期北极狐生长性能、肝脏脂肪酸组成及肝脏型脂肪酸结合蛋白(L-FABP)和脂肪酸转运蛋白(FATP)基因表达的影响。试验选取48只157日龄、平均体重为(5 658±47)g的健康雄性北极狐,随机分成4组,每组12个重复,每个重复1只。Ⅰ组饲粮中添加12.00%鱼油和2.00%豆油,n-6/n-3 PUFA比值为3.00;Ⅱ组饲粮中添加9.38%玉米油和4.62%豆油,n-6/n-3 PUFA比值为18.03;Ⅲ组饲粮中添加12.00%玉米油和2.00%豆油,n-6/n-3 PUFA比值为40.83;Ⅳ组饲粮中添加1.50%鱼油和12.50%玉米油,n-6/n-3 PUFA比值为136.36。各组饲粮除油脂组成和配比不同外,其他原料一致。预试期7 d,正试期40 d。结果表明:1)饲粮n-6/n-3 PUFA比值对冬毛期北极狐的平均日增重(ADG)、平均日采食量(ADFI)和料重比(F/G)有极显著影响(P0.01)。Ⅰ和Ⅳ组的ADG极显著高于Ⅱ和Ⅲ组(P0.01),Ⅰ、Ⅱ和Ⅳ组的ADFI极显著高于Ⅲ组(P0.01),Ⅳ组的F/G极显著低于Ⅱ和Ⅲ组(P0.01)。2)饲粮n-6/n-3 PUFA比值对冬毛期北极狐肝脏单不饱和脂肪酸(MUFA)、PUFA、n-3 PUFA和n-6 PUFA的含量有显著或极显著影响(P0.05或P0.01),对肝脏饱和脂肪酸(SFA)含量无显著影响(P0.05)。Ⅰ和Ⅳ组肝脏n-3 PUFA含量极显著高于Ⅱ和Ⅲ组(P0.01),Ⅱ和Ⅲ组肝脏n-6 PUFA含量极显著高于Ⅰ和Ⅳ组(P0.01)。3)饲粮n-6/n-3 PUFA比值对冬毛期北极狐肝脏L-FABP mRNA相对表达量无显著影响(P0.05),但极显著影响肝脏FATP mRNA相对表达量(P0.01)。Ⅰ和Ⅳ组肝脏FATP mRNA相对表达量极显著高于Ⅱ和Ⅲ组(P0.01)。由此可见,饲粮添加1.50%鱼油与12.50%玉米油的混合油脂,即饲粮n-6/n-3 PUFA比值为136.36时,上调了肝脏中FATP基因的表达,增加了肝脏长链脂肪酸的转运及利用效率,促进了冬毛期北极狐的生长。     

膨化亚麻籽对北京油鸡生长性能、屠宰性能、血浆生化指标、抗氧化能力和肌肉n-3多不饱和脂肪酸沉积量的影响

本试验旨在研究饲粮添加膨化亚麻籽对北京油鸡的生长性能、屠宰性能、血浆生化指标及肌肉n-3多不饱和脂肪酸(PUFA)沉积量的影响。试验选取10周龄北京油鸡(雌鸡)450只,随机分为5组,每组6个重复,每个重复15只鸡,试验期8周。在基础饲粮中分别添加0(阴性对照)、9%的亚麻籽(阳性对照)及9%、12%、15%的膨化亚麻籽,制成5种试验饲粮,分别命名为E0、F9、E9、E12、E15。结果表明:1)E9组生长性能和屠宰性能与F9组相比无显著差异(P>0.05)。与E0组相比,添加膨化亚麻籽对北京油鸡生长性能和屠宰性能均无显著影响(P>0.05)。2)与F9组相比,E9组血浆超氧化物歧化酶(SOD)的活性和丙二醛(MDA)的含量差异不显著(P>0.05)。相比于E0组,添加膨化亚麻籽显著降低北京油鸡肌肉中SOD的活性(P<0.05),同时显著提高血浆MDA的含量(P<0.05)。3)E12组肌肉中n-3PUFA沉积量最高,为(2.16±0.97)g/kg,是E0组5.68倍,且显著高于E0组(P<0.05),但与F9组无显著差异(P>0.05)。由此可见,亚麻籽膨化后可以显著提高n-3PUFA的沉积量,但相同添加量的亚麻籽和膨化亚麻籽对n-3PUFA的沉积量的影响没有显著差异;综合生产工序及成本,不建议使用膨化亚麻籽作为生产富含n-3PUFA鸡肉的油鸡饲料原料。     

不同n-6/n-3多不饱和脂肪酸比值对LPS诱导的断奶仔猪肠道形态的影响

为探讨n-6/n-3多不饱和脂肪酸(PUFA)比值为10或20对断奶仔猪生长性能及LPS诱导的肠道形态的影响,试验选用24头28 d断奶、平均体重(6.8±0.55)kg的荣昌小公猪,采用2×2因子试验设计,日粮类型(n-6/n-3PUFA比值为10和20)和免疫应激(注射LPS和生理盐水),试验期21 d。第21天,每日粮处理组一半的仔猪腹膜注射大肠杆菌脂多糖(LPS)或生理盐水,3 h后屠宰仔猪采集肠道样品。结果表明:在试验的0~7 d和0~21 d,采食n-6/n-3 PUFA比值为10日粮的仔猪饲料转化效率显著高于采食n-6/n-3 PUFA比值为20日粮的仔猪(P<0.05);注射LPS显著降低了断奶仔猪空肠绒毛高度与隐窝深度的比率(P=0.01),但两种n-6/n-3 PUFA比值的日粮对LPS诱导的仔猪肠道形态损害没有缓解作用。     

饲粮 ｎ-６／ｎ-３多不饱和脂肪酸比例对鹅肌肉脂肪酸组成的影响

本文旨在探讨饲粮 ｎ-６／ｎ-３多不饱和脂肪酸（ＰＵＦＡ）比例对扬州鹅肌肉脂肪酸组成的影响。试验选取 １６０只健康、体重接近的 ２１日龄扬州鹅,随机分成 ４组,分别饲喂 ｎ-６／ｎ-３ＰＵＦＡ比例为 １２∶１、９∶１、６∶１及 ３∶１的饲粮,于 ７０日龄时取胸肌和腿肌,进行脂肪酸组成的测定。结果表明：１）在胸肌中,亚油酸的含量 ９∶１组显著高于 ３∶１组（Ｐ＜０．０５）,而与其他各组之间无显著差异（Ｐ＞０．０５）;α－亚麻酸的含量 ３∶１组显著高于 ６∶１和 ９∶１组（Ｐ＜０．０５）,极显著高于１２∶１组（Ｐ＜０．０１）。２）在腿肌中,亚油酸的含量 １２∶１和 ６∶１组均显著高于 ３∶１组（Ｐ＜０．０５）,而与９∶１组无显著差异（Ｐ＞０．０５）;α－亚麻酸的含量 ３∶１组显著高于 ６∶１组（Ｐ＜０．０５）,极显著高于１２∶１和 ９∶１组（Ｐ＜０．０１）。综上所述,鹅肌肉中 ｎ-６／ｎ-３ＰＵＦＡ比例随饲粮中该比例的下降而下降,并以 ３∶１组最低,但除 １２∶１组的腿肌 ｎ-６／ｎ-３ＰＵＦＡ比例较高外,其他各组比例均在世界卫生组织推荐的适于人体健康的（６∶１）～（１０∶１）的比例范围内。     

Effects of the Ratio of n-6:n-3 Polyunsaturated Fatty Acids in the Maternal Diet on Immunoglobulins, Fatty Acid Composition, and Performance of Lactating Sows and Suckling Piglets under Conditions of Low Maternal Energy Intake

This experiment was conducted to investigate the effects of different ratios of n-6:n-3 polyunsaturated fatty acids (PUFA) in sow diets on the performance of lactating sows and their piglets at low digestible energy intakes.Twenty-one pregnant Landrace sows were assigned to one of three diets from day 108 of gestation until weaning (26 to 29 d),containing n-6∶n-3 PUFA ratios of 3∶1,8∶1 and 11∶1.The effects on sow and litter production traits and on sow body condition were examined.There were no differences among treatments in daily feed intakes or in changes in sow weight and back-fat levels during lactation.Litter size,litter weight at birth and weaning and litter average daily weight gain were also unaffected by treatment.As expected,large differences were observed in n-6 and n-3 fatty acids in the colostrum and plasma of sows and piglets (P ＜ 0.01 ).The ratio of n-6∶n-3 PUFA the diet was positively correlated with those in colostrum,sow plasma and piglet plasma ( R2 =0.55,0.80 and 0.80,respectively).Sow plasma insulin and IGF-I levels at weaning were unaffected by the treatments.Plasma leptin ( P ＜ 0.05) concentrations were increased in sows fed the diet with a n-6∶ n-3 ratio of 8∶1.Immunoglobulin concentrations in colostrum were not altered by dietary treatment.Plasma IgG concentrations at d 14 were highest in piglets from sows fed the 8∶1 ratio of n-6∶n-3.Furthermore,this group had the highest IgA concentrations at day 21 of lactation compared with the other two groups ( P ＜ 0.05 ).In summary,our study demonstrated that at low digestible energy levels,altering the ratio of n-6∶n-3 PUFA in the diets for lactating sows affected immune components and the fatty acid composition of lactating sows and their piglets.Further studies are needed to examine whether higher levels of fat supplementation than those used in the present study ( 1.5％ ) can successfully enhance performance.     

饲粮n-6/n-3多不饱和脂肪酸比例对畜禽健康和产品品质的影响

现今人类膳食中n-6多不饱和脂肪酸(PUFA)大多都是过量的,但n-3 PUFA却严重不足.研究表明,n-6/n-3 PUFA比例平衡对畜禽健康和产品品质有着重要意义,n-6/n-3 PUFA比例平衡成为当下最受关注的问题.本文综述了n-6/n-3 PUFA比例平衡的营养生理作用以及对畜禽产品品质的影响及如何改善畜禽产品中的n-6/n-3 PUFA比例.     

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.