日粮中不同油脂对肉鸡小肠组织形态的影响

本试验研究了日粮中添加不同油脂对42日龄肉仔鸡小肠组织形态的影响。试验选取324只1日龄AA肉鸡,随机分成6组,饲喂基础日粮的对照组(CON组),基础日粮添加豆油(SO组),基础日粮添加猪油(LO组),添加以棕榈油为主的配比油脂(COP组)、以椰子油为主的配比油脂(COC组)、多种植物油配比的油脂(COV组)。试验期42d。结果表明:(1)油脂主要影响十二指肠和空肠的微观结构。(2)SO组的十二指肠绒毛高度高于CON组(P0.05)。(3)LO组的十二指肠与空肠的绒毛高度和隐窝深度均高于CON组(P0.01)。(4)COP组的十二指肠的绒毛高度与隐窝深度的比值高于CON组(P0.05)、LO组(P0.01)和SO组(P0.05),空肠的隐窝深度低于LO组(P0.05)。(5)COC组的空肠隐窝深度低于CON组(P0.05)和LO组(P0.01),空肠绒毛隐窝比值高于CON组(P0.05)、LO组(P0.01)和SO组(P0.05)。(6)COV组的十二指肠的隐窝深度低于LO组(P0.05),绒毛高度与隐窝深度的比值高于SO组(P0.05)和LO组(P0.01),空肠绒毛高度与隐窝深度的比值高于LO组(P0.05)。综上所述,油脂有促进十二指肠和空肠组织形态发育的作用,从提高绒毛表面积考虑,配比椰子油效果最好。     

椰子油和单月桂酸甘油酯对断奶仔猪生产性能及粪便微生物的影响

研究椰子油和单月桂酸甘油酯对断奶仔猪生长性能、血清生化指标及粪便微生物的影响.结果表明:饲料中添加椰子油和单月桂酸甘油酯对断奶仔猪生产性能影响差异不显著(P＞0.05),豆油组较椰子油组中添加单月桂酸甘油酯平均日增重效果更好(P＜0.05).与豆油组相比,椰子油组血清甘油三酯含量显著降低(P＜0.05);添加单月桂酸甘油酯血清甘油三酯含量显著降低(P＜0.05),碱性磷酸酶极显著升高(P＜0.01);与豆油加椰子油组相比,添加单月桂酸甘油酯血清中总胆固醇、甘油三酯和肌酐含量显著提高(P＜0.05),血清中碱性磷酸酶极显著提高(P＜0.01);椰子油组较豆油组中添加单月桂酸甘油酯,血清中总胆固醇、甘油三酯和肌酐含量显著提高(P＜0.05),总蛋白含量极显著提高(P＜0.01),血清中碱性磷酸酶含量极显著降低(P＜0.01).椰子油和单月桂酸甘油酯都能极显著降低粪便中总菌落数(P＜0.01).     

日粮中添加亚麻籽油提高鸡肉中n-3PUFA含量的研究

选择216只21日龄罗斯308商品代肉用母雏,随机分为3组,每组6个重复,每个重复12只鸡.第1组为对照组,在玉米-豆粕型基础日粮上添加5%混合油,处理组分别在基础日粮中添加3%亚麻籽油(2组)和5%亚麻籽油(3组),试验期3周,旨在研究在日粮中添加不同水平的亚麻籽油对鸡肉中n-3PUFA含量和肉鸡生产性能影响.试验结果表明:与对照组相比,3%、5%亚麻籽油组肌肉组织中n-3C18:3、n-3C20:5和n-3PUFA含量显著提高(P＜0.05),n-6/n-3比值显著降低(P＜0.05),n-3C22:6水平则变化不大(P＞0.05).5%亚麻籽油组n-3PUFA总量显著高于3%亚麻籽油组(P＜0.05),n-6/n-3比值低于3%亚麻籽油组(P＞0.05).n-3C18:3在胸肌和腿肌中的沉积量显著高于肝脏(P＜0.05),n-3C20:5、n-3C22:6在胸肌和腿肌中的沉积量显著低于肝脏(P＜0.05).添加3%、5%亚麻籽油对肉鸡生产性能无显著性影响(P＞0.05).以上结果表明,肉鸡饲粮中使用亚麻籽油,可生产出n-3PUFA含量较高,n-6/n-3值较低,对人类健康有益的功能性鸡肉产品.     

饲料及饲养试验烟酸铬对肉鸡生产性能、胴体品质及血液生化指标的影响

选择1日龄艾维茵商品肉鸡360羽,随机分成3组,每组3个重复,每个重复40羽,试验期为6周.研究了在日粮中分别添加0,0.2,0.4 mg/kg铬量的烟酸铬对肉鸡生产性能、胴体品质及血液生化指标的影响.结果表明:在0～6周龄的肉鸡日粮中添加不同水平的烟酸铬对肉鸡生产性能无显著影响(P＞0.05).但添加烟酸铬可明显改善胴体品质,显著提高胸肌率(P＜0.05)、降低腹脂率(P＜0.01),对肝脂率、屠宰率、净膛率却无显著影响(P＞0.05).当添加0.4 mg/kg铬量的烟酸铬时, 却能显著降低血清中葡萄糖(P＜0.05)、总胆固醇(P＜0.05)及甘油三酯的含量(P＜0.01),并显著提高血清中高密度脂蛋白-胆固醇的质量浓度(P＜0.05).     

饲料添加小麦秸秆生物质炭对肉鸡生长、屠宰性能和脂质代谢的影响

旨在研究小麦秸秆生物质炭对肉鸡生产性能、屠宰性能和脂质代谢的影响。试验选用100只22日龄、健康状况良好、体重670 g左右的罗斯308肉鸡,随机分成4组。对照组饲喂基础日粮,试验组分别饲喂添加1%、5%和10%小麦秸秆生物质炭的基础日粮,试验期33 d。结果表明:1)与对照组相比,添加5%的小麦秸秆生物质炭肉鸡的平均日增重增加10.12%(P0.05);胸肌率提高23.42%(P0.05);添加5%和10%的小麦秸秆生物质炭肉鸡的腹脂率分别降低31.44%和23.02%(P0.05);试验组肉鸡的料重比均在一定程度上低于对照组,但无显著差异(P0.05);2)与对照组相比,添加5%的小麦秸秆生物质炭显著降低肉鸡血清总胆固醇含量(P0.05);试验组显著降低肉鸡血清三酰甘油含量(P0.05),但对肉鸡血清葡萄糖、低密度脂蛋白胆固醇和高密度脂蛋白胆固醇含量没有显著影响(P0.05);3)虽然添加小麦秸秆生物质炭增加了单位饲料成本,但添加1%和5%小麦秸秆生物质炭试验组每千克肉鸡增重饲料成本分别比对照组降低8%和6%。因此,饲料添加一定量的小麦秸秆生物质炭可以减少肉鸡腹脂沉积,降低血清总胆固醇和三酰甘油含量,在一定程度上有助于改善肉鸡的屠宰性能和生产性能。     

金针菇菇脚对肉鸡血清生化指标和脂肪沉积的影响

目的：研究金针菇菇脚（Flammulina velutipes stembase,FVS）对Arbor Acres（AA）肉鸡血清生化指标、腹脂沉积、肝脏以及肌肉中脂肪含量的影响。方法：选用1 日龄AA肉鸡270 羽,随机分为5 个处理组（每个处理组3 个重复,每个重复18 只）：空白组（饲喂基础日粮）、抗生素组（基础日粮＋5 mg/kg黄霉素）、3 个水平的FVS组（基础日粮＋2%、4%、6% FVS,均为质量分数,下同）,实验期为42 d。结果：1）与空白组相比,日粮中添加2%和6%的FVS可显著降低肉鸡血清中甘油三酯（triglyceride,TG）含量（P＜0.05）;2）各剂量的FVS均可降低21 日龄肉鸡血清中总胆固醇（total cholesterol,TC）含量（P＜0.05）,显著提高21 日龄肉鸡血清中瘦素（leptin,LEP）含量（P＜0.05）,而对高密度脂蛋白胆固醇（high density lipoprotein cholesterol,HDL-C）和低密度脂蛋白胆固醇（low density lipoprotein cholesterol,LDL-C）水平无显著影响（P＞0.05）;3）与空白组相比,FVS可显著提高肉鸡体质量（P＜0.05）,各剂量的FVS可明显降低胸肌、腿肌、肝脏脂肪含量,而各组肉鸡粪便中脂肪含量无显著差异（P＞0.05）;4）与空白组相比,日粮中添加4%和6%的FVS可显著降低42 日龄肉鸡腹脂率（P＜0.05）,日粮中添加2%和6%的FVS可显著提高42 日龄肉鸡的激素敏感脂肪酶（hormone-sensitive lipase,HSL）活力（P＜0.05）。结论：在肉鸡饲粮中添加FVS能够促进肉鸡生长,同时起到一定的降血脂和减少机体脂肪沉积的作用。     

不同剂型维生素E对肉鸡生长性能、血清生化和抗氧化功能的影响

研究比较维生素E(VE)和微囊化VE(MVE)对肉鸡生产性能、血清生化指标和抗氧化能力的影响。试验选用1日龄AA肉仔鸡360只,随机分成3组,每组6个重复,每个重复20只。对照组(CON组)饲喂基础日粮(不添加VE),试验组分别在基础日粮中添加20 IU/kg普通VE(VE组)和20 IU/kg微囊化VE(MVE组)。试验期为42 d,分别于肉鸡21 d和42 d时,测定生产性能,并采取血样,测定血清生化指标和抗氧化指标。结果表明:1)与CON组相比,VE和MVE组对肉鸡21 d的生产性能均无显著影响(P0.05),但MVE组肉鸡22~42 d和1~42 d的平均日增重均显著提高(P0.05)。2)与CON组相比,VE和MVE组显著降低了肉鸡21 d和42 d血清的尿素氮水平(P0.05),且血清肌酐水平在21 d时有下降趋势(P=0.09),血清碱性磷酸酶含量在42 d时有升高趋势(P=0.09)。3)21 d时,MVE组血清总蛋白和球蛋白显著高于CON组(P0.05),VE组无显著差异(P0.05);42 d时,与CON组相比,MVE组血清总蛋白和白蛋白显著提高(P0.05),VE组无显著差异(P0.05)。4)21 d时,VE和MVE组血清VE含量相对于CON组有升高趋势(P=0.08);42 d时,与CON组相比,日粮中添加MVE显著提高了血清总超氧化物歧化酶和谷胱甘肽过氧化物酶活性(P0.05),VE组无显著差异(P0.05)。日粮添加微囊化VE(MVE)能够改善肉鸡的生长性能,提高肉鸡体内的蛋白质合成代谢功能,并能够提高肉鸡的血清抗氧化能力。     

甜菜碱对肉鸡屠宰性能及胸肌肉品质的影响

选用120 只1 日龄艾拔益加（arbor acres,AA）肉鸡随机分为2 组,每组6 个重复,每重复10 只。对照组饲喂基础日粮,实验组在基础日粮中添加750 mg/kg甜菜碱。结果表明,甜菜碱显著提高了肉鸡胸肌率和胸肌中粗蛋白含量（P＜0.05）,并显著提高胸肌pH24 h值,降低48 h滴水损失（P＜0.05）,但对肉色无显著影响（P＞0.05）;甜菜碱显著提高了胸肌中总超氧化物歧化酶活力和谷胱甘肽含量,降低了丙二醛含量（P＜0.05）。结果提示,甜菜碱能有效提高胸肌率,且能提高胸肌肉中粗蛋白含量和胸肌pH值、增强胸肌系水力及胸肌的抗氧化功能。     

蛋氨酸对肉鸡屠宰性能、肉品质及肌肉抗氧化的影响

为了研究日粮蛋氨酸水平对肉鸡屠宰性能、肉品质及肌肉抗氧化的影响,实验选用1 日龄艾拔益加肉鸡144 只,随机分为3 组,每组6 个重复,每个重复8 只。对照组日粮蛋氨酸水平为0.50%（1～21 d）和0.44%（22～42 d）,高、低蛋氨酸组日粮蛋氨酸水平分别为对照组的130%和70%。结果表明：与对照组相比,日粮高蛋氨酸能够显著提高肉鸡胸肌率（P＜0.05）,低蛋氨酸则显著降低肉鸡全净膛率（P＜0.05）;日粮高蛋氨酸显著降低胸肌剪切力（P＜0.05）、显著提高24 h时胸肌的pH值和a*值（P＜0.05）,而低蛋氨酸显著提高胸肌的L*值（P＜0.05）;日粮高蛋氨酸显著升高胸肌总抗氧化能力（P＜0.05）,低蛋氨酸显著降低胸肌谷胱甘肽含量（P＜0.05）。因此,日粮蛋氨酸水平可能通过调节肌肉蛋白质沉积和抗氧化功能而影响肉鸡屠宰性能和肌肉品质。     

牛磺酸对肉鸡生长性能、肉品质及肌肉抗氧化功能的影响

目的:研究牛磺酸(taurine,TAU)对肉鸡生长性能、肉品质和肌肉抗氧化能力的影响。方法:选取384只1日龄‘艾拔益加’肉鸡,随机分为4组,每组12个重复,每个重复8只。对照组饲喂基础饲粮,实验组分别在基础饲粮中添加0.25%、0.5%、0.75%(以基础饲粮总质量计,下同)的TAU。实验周期42 d,分为前期(1～21 d)和后期(22～42 d)。结果:与对照组相比,TAU处理组均能显著提高肉鸡实验前期的平均日增体质量、实验后期的平均日采食量以及实验全期的平均日增体质量和平均日采食量(P0.05),其中添加0.25%和0.5%的TAU能显著提高肉鸡实验前期的平均日采食量(P0.05),显著降低实验全期的料重比(P0.05);TAU处理组能显著提高胸肌pH_(24 h)(P0.05),其中添加0.5%TAU能显著降低胸肌的滴水损失率、蒸煮损失率和黄度(P0.05);日粮添加TAU能显著提高胸肌中谷胱甘肽过氧化物酶活力(P0.05),显著降低丙二醛含量(P0.05),并显著提高胸肌中谷胱甘肽过氧化物酶4、谷胱甘肽过氧化物酶及超氧化物歧化酶mRNA的表达水平(P0.05)。结论:在日粮中添加不同水平的TAU可提高肉鸡的生长性能,改善肉鸡胸肌的肉品质和抗氧化功能,其中以0.5%的添加量效果最佳,这为TAU改善肉品质健康的研究提供了参考。     

Short communication: Linear discriminant analysis and type of oil added to dairy goat diets

Gas chromatography fatty acid (FA) analysis of 112 milk fat samples from dairy goats fed a basal diet with no added oil or the same diet with 1 of 3 vegetable oils added [high oleic sunflower oil (HOSFO), regular sunflower oil (RSFO), or linseed oil (LO)] was used to identify the type of diet consumed through linear discriminant analysis. Twenty variables (19 FA and 1 FA ratio) were selected as valid predictors out of 84 variables tested. The Mahalanobis squared distance was minimal between HOSFO and RSFO groups and maximal between control and LO groups. Cross-validation showed that only one observation from RSFO group was misclassified into the HOSFO group. We concluded that linear discriminant analysis is a useful method to classify milk fat samples from dairy goats according to the particular vegetable oil (of the 3 oils tested here) added to the basal diet.     

不同种类高膳食油脂对小鼠血脂、肝脂及尿酸的影响

为了探讨猪油、植物油及其调和油对血脂、肝脂及血尿酸的影响,评估其对特殊人群的健康潜在风险,本文研究以小鼠为模型,模拟居民用油习惯,将50只8周龄雄性C57BL/6J小鼠随机均分为葵花籽油组(SSO)、豆油组(SO)、猪油组(LO)、葵花籽油与猪油调和油组(SSO-L)、豆油与猪油调和油组(SO-L)5组,模拟我国部分人群(5%~10%)日均烹调油脂高摄入水平(95g/d),每组日粮中分别添加10.5%的不同油脂,饲喂8周后采集血液和肝脏组织,检测血清和肝脏指标。结果显示,相比于其他各组,LO组在体脂和血脂方面都有显著或极显著升高(p0.05,p0.01)。而SSO-L组和SO-L组在肝脂方面显著高于对应的SSO组和SO组(p0.05)。同时,SSO-L组和SO-L组的SUA和肝脏XOD水平都显著高于LO组(p0.05)。表明在95 g/d的膳食油脂摄入水平下,猪油会极大增加肥胖和患脂肪肝病的风险。葵花籽油与猪油调和油和豆油与猪油调和油也会通过升高尿酸水平来增大痛风和脂肪肝的患病风险。此外,长期以该水平摄入这两种调和油对肝脏功能也有明显损伤。在该摄入水平下,豆油为较优选择。     

Identification of odour‐active compounds in muscle of brown trout (Salmo trutta) as affected by dietary lipid sources

The effect of fatty acid composition on odour‐active compounds in brown trout (Salmo trutta) muscle was evaluated. The fillets were obtained from three groups of fish fed experimental diets containing either fish oil (FO), soybean oil (SO) or linseed oil (LO). Muscle fatty acid composition was shown to be influenced by diet. Thirty‐one odorous compounds were detected by gas chromatography/olfactometry (frequency‐of‐detection method). Most of these compounds were formed by the oxidation of unsaturated fatty acids. Independently of diet, (E)‐2‐pentenal, (E)‐2‐pentenol and (E)‐2‐hexenol contribute strongly to the odour of brown trout. (E,Z)‐2,4‐Heptadienal was detected with high frequency in fish fed diets containing high levels of n‐3 PUFAs (FO and LO groups). Hexanal, (E)‐2‐hexenal and 2‐nonanol seem to contribute most to the odour of fish fed diets containing vegetable oils. Many odorous compounds were derived from the oxidation of mono‐ and di‐unsaturated fatty acids, which could be promoted by high levels of PUFAs. © 2002 Society of Chemical Industry     

Vegetable oil blends with α-linolenic acid rich Garden cress oil modulate lipid metabolism in experimental rats

Vegetable oil blends with modified fatty acid profile are being developed to improve n-6/n-3 polyunsaturated fatty acid (PUFAs) ratio in edible oils. The objective of this study is to develop vegetable oil blends with α-linolenic acid (ALA) rich Garden cress oil (GCO) and assess their modulatory effect on lipid metabolism. Sunflower oil (SFO), Rice bran oil (RBO), Sesame oil (SESO) were blended with GCO at different ratios to obtain n-6/n-3 PUFA ratio of 2.3–2.6. Native and GCO blended oils were fed to Wistar rats at 10% level in the diet for 60 days. Serum and liver lipids showed significant decrease in Total cholesterol (TC), Triglyceride (TG), LDL-C levels in GCO and GCO blended oil fed rats compared to native oil fed rats. ALA, EPA, DHA contents were significantly increased while linoleic acid (LA), arachidonic acid (AA) levels decreased in different tissues of GCO and GCO blended oils fed rats. In conclusion, blending of vegetable oils with GCO increases ALA, decreases n-6 to n-3 PUFA ratio and beneficially modulates lipid profile.     

Effect of dietary linseed oil and α-tocopherol on pork tenderloin (Psoas major) muscle

The effect of linseed oil and α-tocopheryl acetate on the fatty acid composition and the susceptibility to oxidation of lipid fraction from pork tenderloin (Psoas major) muscle has been studied. Muscles were obtained from animals fed on diets with the same ingredients excepting the oil source [sunflower (C), linseed (L) and linseed and olive (1/1, w/w) (LO)] and α-tocopherol [20 (C, L and LO) or 200 (LOE and LE) mg/kg diet]. The n-6/n-3 ratio in pork tenderloin was markedly modified by dietary linseed oil administration, which was due to the increase in the C18:3n-3 (and total n-3 fatty acids) and the decrease in the C18:2n-6 (and total n-6 fatty acids) contents (P<0.05). The α-tocopherol content of tenderloin from batches LE and LOE was about 2.8 mg/kg of muscle, significantly greater (P<0.05) than about 0.7 mg/kg muscle found in tenderloin from pigs receiving C, L and LO. Dietary supplementation with α-tocopheryl acetate markedly reduced tenderloin lipid oxidation from animals fed diets enriched in n-3 fatty acids (L or LO vs LE or LOE).     

Influence of bioflavonoids from the radix extract of Scutellaria baicalensis on the level of serum lipids, and the development of laboratory rats fed with fresh and oxidized fats

The aim of this study was to assess the influence of bioflavonoids from the radix of Scurellaria baicalensis on the level of lipids, via the determination of the concentrations of triglycerides, total cholesterol and high-density lipoprotein (HDL) cholesterol in the plasma of laboratory rats fed high-fat and high-cholesterol diets, and via the calculation of their atherogenic index. We also studied the influence of bioflavonoids on their physical development by measuring the increase in their body mass and liver mass. The rats were fed a diet with a 15% content of fresh or oxidized lard or sunflower oil, along with 0.5% added cholesterol. 0.05% S. baicalensis radix extract was added to the diet of half of the rats as the source of bioflavonoids. In the group of rats fed a diet containing oxidized oil we observed a significantly lower increase in body mass (15.5 +/- 7.6 g/4 weeks/rat) than that observed for the control rats (77.0 +/- 15.7 g/4 weeks/rat). The addition of S. baicalensis radix extract to the diet raised the increase in body mass in the groups receiving oil as the source of fat; those receiving fresh oil had a 40% increase, and those receiving oxidized oil showed a 300% increase relative to the appropriate controls. In all the groups of rats fed a diet with bioflavonoids added, a beneficial decrease in the plasma triglyceride content was observed relative to the appropriate controls. In the plasma of rats on a diet containing the extract and fresh or oxidized oil or fresh lard, we observed a beneficial reduction in the total cholesterol level relative to the appropriate controls. The atherogenic index was higher for the group of animals fed with fresh lard than for those fed with fresh oil, and higher for those fed with oxidized oil than for those fed with oxidized lard. The addition of bioflavonoids to the diet beneficially reduced the atherogenic index value in the group fed with fresh oil, and increased its value in the group fed with oxidized lard.     

日粮中添加不同油脂对鸡蛋工艺特性及质构指标的影响

摘 要：目的 本试验旨在探究蛋鸡饲粮添加不同油脂后对鸡蛋起泡性、乳化性、凝胶特性及蛋黄TPA、剪切力及蛋黄膜强度的影响。方法 在玉米-豆粕型基础日粮的基础上,分别添加1.5％豆油、1.5％猪油、1.5％混合油脂。结果 试验结果表明：与对照组相比,添加1.5％的猪油和混合油脂会不同程度的降低鸡蛋的工艺特性,显著增加蛋黄的硬度、咀嚼性;而1.5％豆油对鸡蛋的工艺特性及质构指标不会造成不良影响。结论 因此,为了满足蛋鸡生长能量需求及蛋品功能特性,建议在日粮中添加1.5％豆油。     

n-3多不饱和脂肪酸饮食对小鼠肥胖及相关细胞因子的影响

目的：研究n-3 多不饱和脂肪酸(polyunsaturated fat acids,PUFAs)饮食对小鼠肥胖程度及相关细胞因子血清水平的影响,探讨其作用机理。 方法：将健康小鼠分为高饱和脂肪酸饮食组、n-3 多不饱和脂肪酸饮食组和对照组,记录每周小鼠进食量和体质量,实验结束时用ELISA 法检测小鼠血清增食因子A(orexin-A)、抵抗素(resistin)、脂联素(adiponectin)水平。 结果：n-3 多不饱和脂肪酸饮食组小鼠与高饱和脂肪酸饮食组小鼠相比,肥胖程度明显降低 (P ＜ 0.05),血清的增食因子A 水平明显降低(P ＜ 0.05),血清的抵抗素水平明显升高(P ＜ 0.05),血清的脂联素水平升高但无统计学差异;n-3 多不饱和脂肪酸饮食组小鼠的各项指标和对照组相比均无统计学差异。结论：n-3 多不饱和脂肪酸饮食与饱和脂肪酸饮食相比,可抑制肥胖的发生和发展。     

Animal performance and milk fatty acid profile of dairy goats fed diets with different unsaturated plant oils

The effect of supplementing a basal diet with 1 of 3 plant oils on productive efficiency and milk fatty acid composition was studied in dairy goats. Sixteen Malagueña goats were used in a 4 × 4 Latin square experiment with 21-d periods and 4 goats per treatment. The basal diet comprised 30% alfalfa hay and 70% pelleted concentrate. Experimental treatments were control (basal diet without added oil) and the basal diet supplemented with 48 g/d of high oleic sunflower oil (HOSFO), regular sunflower oil (RSFO), or linseed oil (LO). Dry matter intake and body weight were not affected by treatments. Milk production was higher in HOSFO treatment and milk fat content was higher in RSFO and LO treatments, although no differences in milk energy production or milk renneting properties were found. The RSFO and LO treatments increased the proportion of vaccenic acid in milk fat more so than the HOSFO diet, and rumenic acid followed the same pattern. The content of trans10-18:1 remained low in all experimental diets (<0.7% of total fatty acid methyl esters) although HOSFO and RSFO diets increased it. The variations in the fatty acid profiles observed with the 4 diets, mainly the unsaturated fatty acid isomer contents, are extensively discussed. Compared with that in the control diet, the n-6:n-3 fatty acid ratio in milk fat substantially decreased with the LO, increased with RSFO, and did not change with HOSFO. The addition of moderate amounts of LO to the diets of dairy goats has favorable effects on milk fatty acid composition from the point of view of the human consumer, without negative effects on animal performance.     

Atlantic salmon (Salmo salar) muscle structure integrity and lysosomal cathepsins B and L influenced by dietary n-6 and n-3 fatty acids

This study had two main objectives: first, to evaluate the impact of different types and levels of dietary n-6 and n-3 fatty acids (FAs) on Atlantic salmon muscle structure integrity; second, to highlight a possible role of lysosomes and lysosomal degrading enzymes, cathepsins, in fish muscle structure integrity, in relation to dietary fatty acids. Four groups of Atlantic salmon (90 g starting weight) in fresh water tanks were fed one of four diets containing 23% crude lipids, with 100% of the added oils as either fish oil (FO), rapeseed oil (RO), eicosapentaenoic acid (EPA) enriched-oil or docosahexaenoic acid (DHA) enriched-oil. The RO diet was characterised by low levels of EPA + DHA (10% of total FAs), whereas the EPA and DHA diets were characterised by very high levels of EPA + DHA (>50% of total FAs). Fatty acid composition of the muscle crude lysosomal fraction (CLF) generally reflected the diets. Salmon fed the RO diet presented a muscle CLF FA composition close to the one of the FO group, showing moderate PUFA levels, and comparable cathepsin B and cathepsin L activities, relative gene expression of cathepsin B and cathepsin L in the muscle and rate of myofibre–myofibre detachments post-mortem. Salmon fed the EPA and DHA-enriched-oil diets presented a fairly similar muscle CLF FA composition, but different from the FO and RO groups. In the EPA and DHA groups, the percentage of PUFAs in the muscle CLF, the rate of myofibre–myofibre detachments and the relative gene expression of cathepsin B were higher than in the FO and RO groups. Cathepsin B and cathepsin L total activities in the muscle were however lower in the EPA and DHA groups 0 h post-mortem. Dietary lipids influenced the level of lysosomal degrading enzyme activity cathepsin B and cathepsin L as well as the relative gene expression of cathepsin B. Feeding Atlantic salmon with rapeseed oil and extreme levels of EPA + DHA highlighted the impact of fatty acid composition of the diet on salmon muscle integrity and the complexity of the process involving muscle lysosomes and cathepsins in relation to these dietary fatty acids.