调控鸡蛋胆固醇含量的新营养途径

近年来，随着人们消费水平的提高，鸡蛋的胆固醇和PUFA60含量以及蛋黄颜色的深浅已成为衡量蛋品质的重要指标，直接影响着市场的需求。研究发现，通过营养代谢调控手段，能生产出胆固醇含量低、PUFA含量高的鸡蛋以满足社会的需求。近年来，国内外许多学者在这方面做了大量卓有成效的工作，下面介绍有关营养调控的新认识，供科研和生产参考。[编者按]     

营养成分对鸡蛋胆固醇含量的影响

近年来,随着人们消费水平的提高,鸡蛋中胆固醇、多不饱和脂肪酸(PUFA)的含量以及蛋黄颜色的深浅已成为衡量蛋品质的重要指标,直接影响着市场的需求。研究发现,通过营养代谢调控手段,能改善蛋品质,生产出胆固醇含量低、PUFA含量高的鸡蛋。现将影响鸡蛋胆固醇含量的因素报道如下。1能量物质大量研究表明,蛋鸡日粮中能量或脂肪的浓度过高会使鸡蛋中胆固醇的含量增加。当机体能量贮备足够时,过量摄入能量会表现为体重增加,胆固醇的生物合成提高。2脂类由于日粮中脂肪和胆固醇与家禽机体胆固醇的代谢密切相关,饲料中脂肪、脂肪酸的组成和含量…     

调控鸡蛋胆固醇含量的营养途径

禽蛋类食品营养丰富，是人们日常饮食中普遍喜欢食用的食品。蛋类蛋黄中含有大量胆固醇，胆固醇是生命活动的必需物质，适宜量的胆固醇有利于人体健康，但过量摄入可形成高脂血症，引起动脉粥样硬化，进而诱发冠心病、高血压等一系列心脑血管疾病。利用营养和分子生物学手段对蛋鸡的胆固醇代谢过程进行研究．有利于找到降低鸡蛋中胆固醇含量的措施。笔者综述了通过营养代谢调控的途径来降低鸡蛋中胆固醇含量。     

降低鸡蛋胆固醇含量的营养调控措施

鸡蛋的胆固醇和多不饱和脂肪酸（PUFA）的含量已成为衡量蛋品质的重要指标，蛋黄中胆固醇含量约占蛋黄重的4％。约为200-250mg／枚。如此高的胆固醇含量直接影响着蛋鸡养殖业的发展和蛋产品的市场容量需求。研究发现，通过营养代谢调控手段，即选用适当的方法来降低鸡蛋中胆固醇的含量，进而能生产出胆田醇含量低、多不饱和脂肪酸（PUFA）含量高的鸡蛋来满足消费者的需求。     

降低鸡蛋中胆固醇含量的营养调控技术

本文探讨了通过营养调控技术降低鸡蛋中胆固醇含量,包括调控日粮能量、纤维素以及寡聚糖、微生态制剂、异黄酮物质、中草药、植物固醇、微量元素等营养调控剂的应用。     

降低鸡蛋胆固醇含量的调控措施及其机制

鸡蛋营养价值很高,但由于含有较高浓度的胆固醇从而限制了公众对鸡蛋的消费,开发低胆固醇鸡蛋具有重要的理论价值和现实意义。通过遗传选育和在饲粮中添加脂肪（或脂肪酸）、中草药、植物甾醇、矿物质以及他汀类药物等方法能够有效地降低鸡蛋胆固醇含量。本文从遗传因素、营养因素和非营养因素 ３个方面综述了国内外学者在降低鸡蛋胆固醇领域的最新研究成果。     

降低鸡蛋胆固醇的营养调控措施

胆固醇是细胞膜的重要组分,在维持与营养细胞膜方面起着重要作用,是人类维持正常生理活动所必需的,但人体血液中胆固醇浓度过高会引起高血脂,进而引起高血压、冠心病等一系列心血管疾病.     

鸡蛋品质的营养调控

通过营养调控鸡蛋品质是近年来鸡营养研究的热点之一 ,本文综述了影响鸡蛋品质指标 (蛋重、蛋壳质量、蛋黄颜色、营养价值、孵化率 )的营养因素。     

鸡蛋中胆固醇含量的营养调控措施

随着人们生活水平的不断提高,其膳食结构也在不断变化,除了要求食品营养好外,开始逐渐强调绿色保健化。鸡蛋作为人们餐桌上的常见食品,胆固醇的含量日趋成为消费者和研究者关心的问题。笔者认为,通过鸡日粮营养的调控,可以一定程度的降低鸡蛋的胆固醇含量,适应社会的需求。本文     

几种功能性鸡蛋的调控途径

功能性鸡蛋是指除营养丰富味美之外．还有调节人体生理活动功能的鸡蛋。近年来，国内外利用产蛋鸡高产的特性，开发了许多新型营养保健蛋．对治疗很多疾病起到了积极的作用。本文就几种功能性鸡蛋的作用及生产方法作一综述。     

调控鸡蛋中胆固醇含量的微量营养素

调控鸡蛋中胆固醇含量的微量营养素$山东农业大学动物科技学院@赵晓芳 $中国农业科学院畜牧研究所@张宏福     

我国禽蛋贮存保鲜技术存在的问题及其解决途径

禽蛋在自然温湿条件下,蛋内各种酶的生物学活性较高,蛋外微生物活跃.因此,禽蛋产后,若不进行贮存保鲜处理,虽然在短时期内不会出现散黄、腐败变质现象,但由于微生物通过蛋孔侵入蛋内和蛋内各种分解酶的作用,使蛋内部分营养物质被分解破坏,禽蛋的鲜度、卫生状况、营养价值下降.     

Factors regulating tapeworm populations: dispersion patterns of Taenia hydatigena eggs on pasture

Two grazing trials using 'sentinel' lambs were undertaken to measure changes in the availability of eggs within 30 metres of deposition by dogs infected with Taenia hydatigena. In the first trial the experimental pasture was divided into nine equal plots; in the second trial, each of the nine plots was divided into sub-plots. In each trial, infected dogs were placed on the pasture for 10 days. Lambs were then grazed for 10 days immediately, 36 days and 56 days after the dogs had been removed. Changes in the dispersion pattern of the eggs over time and space were assessed by examination of the lambs for cysts at autopsy. In both trials, eggs spread radially within the grazing zone within 10 days, but 36 days after the removal of the dogs, their availability to the lambs was markedly reduced. In the first trial at five weeks, the height of grass (between 3 cm and 15 cm) did not modify egg availability. In both trials, despite differences in rainfall affecting the growth of grass and associated factors similar egg losses occurred.     

Effects of feeding fermented fish on egg cholesterol content in hens

This study was conducted to investigate the effects of feeding fermented fish (FF) to layers on laying performance, and polyunsaturated fatty acid and cholesterol levels in eggs and plasma. A total of 96, 13-week-old Babcock B380 pullets were used in this study. They were randomly assigned to four numerically equal groups with eight replicates per treatment, three birds per replicate. All the birds were housed in individual cages. The dietary treatments were: Control diet, without FF; FF3 diet containing 3% (w/w) FF, FF6 diet containing 6% (w/w) FF and FF9 diet containing 9% (w/w) FF. The study was carried out for 16 weeks inclusive of two weeks of adjustment. Weekly feed intake and egg production were recorded. Blood plasma cholesterol and fatty acid profiles were assayed at the end of the experiment. FF did not enhance ( P  > 0.05) egg mass but ( P  < 0.05) decreased egg weight slightly. However, egg yolk cholesterol and plasma cholesterol concentrations were reduced ( P  < 0.05) by FF. The n-6:n-3 fatty acids ratio in the egg yolk (Control = 7.9, FF9 = 6.2) and plasma (Control = 10.6, FF9 = 6.2) were decreased by feeding FF. Moreover, FF was able to increase ( P  < 0.05) the docosahexaenoic acid (DHA) concentrations in egg yolk and plasma. In conclusion, this study demonstrated that FF increased DHA and reduced egg yolk cholesterol in poultry eggs.