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.     

各种食用油的营养成分如何，如何吃出健康？

答：判断某种植物食用油的营养价值，最主要的方面就是看它的脂肪酸组成。首先看饱和脂肪酸和不饱和脂肪酸的含量，不饱和脂肪酸含量越多，就越容易被人体消化吸收。除此之外，还要看不饱和脂肪酸里面含单不饱和脂肪酸和多不饱和脂肪酸的比例。     

氧化时长对不同油脂过氧化指标的影响研究

<正>目前人们普遍认为,油脂过氧化后可能含有有毒的脂质过氧化产物,并且可以诱导动物产生氧化应激(Kubow,1992)。饲料中脂质过氧化反应从自由基或单线氧开始,发生一系列的自身催化自由基反应,这些自动氧化反应引起脂质断裂,形成大量的脂质过氧化产物,     

共轭亚油酸作为饲料添加剂的应用研究

共轭亚油酸（conjugated linoleicacid，CLA）是亚油酸的异构体，天然存在于许多生物体内的一类含有共轭双键的微量多不饱和脂肪酸。大量研究结果表明，作为一种新型功能性油脂，CLA具有抗癌、     

浅析多不饱和脂肪酸植物油的负面作用与品种改良

就我国植物油食和现况与相关的主要慢性流行情况作一概述，并从食用油脂肪酸组成，ｎ－３和ｎ－６脂肪酸代谢以及脂质过氧化等方面说明偏食富含多不饱和脂肪酸植物油的潜在危害。并介绍了国内外主要油料作物品种脂肪酸育种改良新动向、及对植物油的合理食用提出建议。     

富含多不饱和脂肪酸动物产品开发的研究进展

对富含多不饱和脂肪酸动物产品开发研究的进展作了综述，为开发此类产品提供参考。     

日粮中添加植物油对鸡肉中ω-6多不饱和脂肪酸含量的影响

100只52周龄蛋鸡分为5组,对照组饲喂基础日粮,试验组在基础日粮中分别添加3%的胡麻油,3%的菜籽油,3%的大豆油和3%的花生油,研究日粮中添加植物油对鸡肉中ω-6多不饱和脂肪酸的影响。结果表明:日粮中添加3%植物油可明显提高生产性能,试验组鸡肉和肝脏中亚油酸(C18:2)的含量都明显高于对照组(P<0.05)。鸡肉和肝脏中试验3组亚油酸(C18:2)的含量分别比对照组提高27.2%和41.5%。     

ω—3不饱和和脂肪酸的生物学作用

由于人们的膳食中饱和脂肪酸／多不饱和脂肪酸（S／P）及ω－6不饱和脂肪酸的比例失调，使得心血管的发病率显著增加。正因为ω－3不饱和脂肪酸的摄入量相对不足，所以人们更加重视ω－3不饱和脂肪酸在脂肪酸促进胎儿和新生儿的大脑发育，抗肿瘤和炎性反应及降低冠心病、高血压、动脉粥样硬化、二型糖尿病等发病率的特殊作用，这些作用源于ω－3的某些生物学作用。本文阐述ω－3功能活性的生物学作用基础。41     

n—3多不饱和脂肪酸营养研究进展

国外对ｎ－３多不饱和脂肪酸（ｎ－３ ＰＵＦＡ）的研究是８０年代展开的。研究发现富含长链ｎ－３脂肪酸－ＥＰＡ（甘碳五稀酸）和ＤＨＡ（甘二碳六稀酸）的鱼油有降低心血管疾病（Ｔｅｍｐｌｅ，１９９６）、增强动物机体免疫机能（Ｆｅｒｎａｎｄｅｓ，１９９５）和正常脑发育（Ｎｅｕｒｉｎｇ６ｒ ｅｔ ａｌ，１９９８）等独特作用。加拿大营养卫生与福利部（１９９０）首次提出人每天ｎ－３ ＰＵＦＡ的摄取量应为日粮能量的０．５％左右。ｎ－３　ＰＵＦＡ是一类特殊的不饱和脂肪酸，其第一个双键位于从碳链甲基端数起的第三个Ｃ原子上…