大豆磷脂在水产饲料中的应用

磷脂是动物神经系统、骨髓、心、肝和脾不可缺少的组成部分,是生物膜的重要组成,添加磷脂能促进鱼类的脑、神经组织、内脏、骨髓的发育健全,还可以节约蛋氨酸的消耗,提高饲料质量。鱼类在孵化后的快速生长中,需要丰富的磷脂来构成细胞的成分,当磷脂的生物合成不能充分满足仔鱼的需求时,便需要在饲料中添加磷脂。磷脂可以提供鱼类自身无法合成的亚麻酸和亚油酸,还能促进甲壳动物对胆固醇的利用,提高甲壳动物的生长、脱壳和成活率。本文综合国内70年代至今的文献,总结了大豆磷脂饲料对鱼和甲壳类动物中的作用。     

饲料中脂肪含量对罗非鱼生长的影响

饲料中脂肪含量对罗非鱼生长的影响庞思成脂肪是动物营养主要的能源物质，在鱼类生长、发育和繁殖过程中不可缺少，其中的一部分作为脂溶性维生素的载体，在代谢中起重要作用。适宜提高饲料脂肪含量，还能节约蛋白质的消耗，提高蛋白质的利用效率。故此，脂肪在鱼类营养上...     

小球藻的营养价值及其在水产动物饲料中的应用

小球藻（Chlorella）是一种单细胞绿藻,含有较高的蛋白质、多种矿物质和微量元素。在水产动物饲料中作为植物蛋白源,营养物质丰富且分布广泛,在促进鱼类生长、提高免疫力中发挥重要作用。饲料中添加小球藻可以替代部分鱼粉,提高营养价值。近年来,随着微藻的大力推广,小球藻逐渐成为优质的饲料添加剂。文章简述了小球藻的营养组成、适宜添加水平以及对鱼类生长性能、消化能力、免疫和体色影响等。     

毛皮动物常用的动物性饲料

1鱼类饲料 鱼类饲料是毛皮动物的动物性蛋白质的主要来源,其消化率高,适口性较好。鱼类饲料在饲喂前可不进行煮熟处理,因生喂比熟喂的营养价值要高,而过度加热会破坏鱼类饲料中的赖氨酸的成分,同时使精氨酸、色氨酸、胱氨酸和蛋氨酸对蛋白质饲料脱水破坏性很敏感。但有些海鱼和淡水鱼中因含有硫胺素酶,而破坏饲料中硫胺素的吸收,所以在饲喂时应把鱼煮熟,并持续数分钟,可使硫胺素酶失活。     

饲料中的糖对水产动物的影响

糖是一种重要的能量物质,其以价格低廉和作用高效被广泛应用于各种饲料.但由于鱼类(特别是肉食性鱼类)是先天性的糖尿病患,从而局限了糖在水产饲料业中的发展.本文拟通过对糖和水产动物间相互关系的论述,阐明在一定的条件和范围内,饲料中的糖对于水产动物的生理、生化活动具有相当重要的作用.同时,通过人为的添加一些糖代谢调节因子来增加水产动物对糖的利用率,对提高水产动物的生长率及免疫力有着显著的效果.     

饲料中适宜动植物蛋白比对淡水白鲳生长的影响

蛋白质是水产动物生长的重要营养元素，也是影响饲料成本的重要因子。而作为水产动物饲料的重要蛋白源-鱼粉，由于其资源量下降，价格昂贵，致使饲料成本过高。因此，寻找新的替代鱼粉的蛋白源，引起了养殖业的关注。一些学者通过动植物蛋白比的研究，发现鱼类、虾以及蟹饲料中适宜的动植物蛋白比有利于动物的生长。相反饲料中的动物蛋白比例过高，并不能取得较好的养殖效益。     

鱼类摄食与促摄食物质的研究进展

近年来,随着植物蛋白源和其它非常规饲料原料在水产配合饲料中的使用量增加,造成配合饲料适口性普遍较差,饲料的适口性问题成为业界普遍关心和亟待解决的一个重要问题。目前,促摄食物质(Feeding stimulants)因其能够提高动物食欲和摄食量,有助于解决当前配合饲料的适口性问题,因此在鱼类和其它水产动物的配合饲料中得到广泛应用。本文就鱼类摄食行为、促摄食物质和促摄食物质调控摄食方式方面的主要研究进展以及未来的研究方向进行了综述。     

用大豆饼代替鱼粉

在发展中国家,由于动物蛋白资源短缺而使配合饲料价格偏高,引起畜、禽和鱼类饲料质量不稳定。在发展中国家中,有多种植物蛋白可以利用,但其中大多数缺乏某些必需氨基酸。在植物蛋白中,大豆中的氨基酸组成较为合理,而且价格比其他高蛋白饲料包括鱼粉便宜。单胃动物和鱼类的蛋白质需要     

鱼类饲料中的抗营养因子和毒素

某些植物在生长代谢过程中，可产生一些对动物生长和健康有害的物质，这些物质对动物如果主要产生抗营养作用，就称为抗营养因子，如果对动物主要产生毒性作用，则称之为毒素。抗营养因子的抗营养作用主要表现为，降低饲料营养物质的利用率、动物生长速度和动物的健康水平。毒素的毒害作用主要是危及动物健康、正常代谢和生长，严重时造成死亡。鱼类饲料中有多种抗营养因子和毒素，现将几种对鱼类生长和健康危害较大的抗营养因子和毒素作简要介绍。1鱼类饲料中抗营养因子1.1抗胰蛋白酶又称为胰蛋白酶抑制因子。主要存在于大豆、豌豆、蚕豆等…     

胆汁酸的生理功能及其对水产动物的影响研究进展

胆汁酸是胆固醇代谢的主要终产物,是胆汁的重要组成成分,对促进动物肠道中胆固醇、脂质和脂溶性维生素的吸收有重要的生理作用。胆汁酸对水产动物的生长性能、消化酶活性、抗氧化功能、免疫功能及糖脂代谢等均有一定影响。本文综述了胆汁酸的生理功能及其对水产动物的影响,进一步明确了胆汁酸的主要组成成分、作用机制和测定方法,对水产动物脂肪肝、肝胆综合症等相关疾病以及促进水产功能性饲料的可持续发展有重要意义。     

Hypolipidaemic effects of potato protein and fish protein in pigs

This study was performed to assess the effects of potato protein and fish protein on concentrations of lipids in plasma and lipoproteins and the expression of genes involved in lipid metabolism in pigs used as an animal model. Therefore, 27 young male pigs with an average body weight of 22 kg were fed diets supplemented with protein extracted from potatoes (containing 849 g protein/kg dry matter), Alaska Pollack fillet as a source of fish protein (containing 926 g crude protein/kg dry matter) or casein which was used as control, for 3 weeks. Diets were formulated to supply identical amounts of each protein to the pigs by the three protein sources, namely 116 g/day in first week and 150 g/day in the second and third week. Pigs fed potato protein had lower concentrations of cholesterol in plasma and LDL than pigs fed casein (p < 0.05); no effect was observed on concentrations of HDL cholesterol and triglycerides. Pigs fed fish protein had lower cholesterol concentrations in plasma, LDL and HDL, and lower triglyceride concentrations in triglyceride-rich lipoproteins than pigs fed casein (p < 0.05). mRNA concentrations of genes involved in bile acid synthesis and cholesterol uptake were higher in pigs fed fish protein than in pigs fed casein (p < 0.05); no effect on these genes was observed in pigs fed potato protein. Expression of genes involved in lipogenesis and fatty acid oxidation was not altered by fish protein. In conclusion, this study shows that fish protein and potato protein lower plasma cholesterol concentrations in pigs. The hypocholesterolaemic effect of fish protein might be in part caused by a stimulation of bile acid synthesis; the reason for the hypocholesterolaemic effect of potato protein requires further elucidation.     

日粮多不饱和脂肪酸对家畜繁殖性能的影响

多不饱和脂肪酸（polyunsaturated fatty acids, PUFAs）作为一种重要的营养物质,能影响家畜繁殖性能。适宜比例的日粮ω-6与ω-3 PUFA能提高家畜成活率,降低早产率,提高精液品质。近年来PUFA的种类、来源及其在家畜体内的相互转化机制引起人们的注意, 作者综述了日粮PUFA通过前列腺素合成和类固醇激素代谢影响家畜繁殖性能的研究进展。      

视黄醇在卵巢发育中的作用研究进展

卵巢发育及功能直接影响动物的繁殖性能,而视黄醇在哺乳动物繁殖过程中有着重要的调节作用。视黄醇在卵母细胞减数分裂、抗应激和类固醇激素合成过程中有着不同的调节功能。本文主要就视黄醇代谢通路及其在动物卵巢中的功能展开综述,为提高动物的繁殖性能提供理论依据。     

油脂酸败及其影响因素

油脂是鱼类生长和代谢过程中最重要的营养素之一。油脂酸败是影响油脂品质的关键因素。文章就油脂酸败机理及影响油脂酸败的因素作一简述。     

鱼类镁营养研究进展

镁在大量的细胞生化反应中扮演着重要角色,它参与生物体内所有的能量代谢,催化或激活300多种酶体系.本文综述了鱼类镁的缺乏症、镁在鱼体内的吸收和代谢以及镁对鱼类生长、体组成、脂肪代谢、免疫、渗透调节等方面的影响,并阐述了镁与其他营养素的相互关系.介绍了鱼类对镁的利用率以及镁需要量的研究概况,对镁的营养生理机制做了简单探讨...     

l-carnitine supplementation and lipid metabolism of rats fed a hyperlipidaemic diet

Until now, there has been no clear knowledge about the effect of dietary carnitine supplementation on lipid metabolism. Therefore, this study was conducted to investigate the effect of a dietary l -carnitine supplementation (500 mg/kg) onx the lipid metabolism of adult rats. Rats fed a hyperlipidaemic basal diet containing 15% lard and 1% cholesterol were used as an animal model. The feeding period was 6 weeks. As parameters of lipid metabolism, the concentrations of individual lipids in plasma, lipoproteins and liver and the fatty acid composition of liver and erythrocyte total lipids were determined. There were no significant differences between the control group and the group receiving the diet supplemented with carnitine on parameters of animal performance (daily body weight gains and feed conversion ratio). As expected, plasma, very low-density lipoproteins (VLDL) and liver exhibited high concentrations of cholesterol. Concentrations of triglycerides and phospholipids in plasma and individual lipoproteins as well as the concentrations of triglycerides, cholesterol and phospholipids in the liver were not significantly altered by dietary carnitine supplementation. The concentration of cholesterol in plasma and liver was increased by dietary carnitine. The fatty acid composition of liver and erythrocyte total lipids was not influenced by dietary carnitine supplementation. In conclusion, this study does not indicate a lipid-lowering effect of dietary carnitine supplementation in hyperlipidaemic rats. Probably, the essential functions of carnitine in metabolism were realized by carnitine which was synthesized endogenously.     

A review of lipoprotein cholesterol metabolism: importance to ovarian function

Cholesterol utilized for steroid synthesis by ovarian tissue may be derived from de novo synthesis or cellular uptake of lipoprotein cholesterol. The majority of blood cholesterol is transported by either low (LDL) or high (HDL) density lipoproteins, depending on the animal species. Prior to vascularization, only HDL are in follicular fluid and contribute sterol to granulosa cells because other lipoproteins are unable to transverse the basement membrane due to their molecular masses. Following vascularization, both LDL and HDL bathe luteal cells. Most species preferentially use LDL cholesterol as a precursor for ovarian steroid synthesis. The LDL uptake by ovarian tissue occurs by receptor-mediated endocytosis. The receptor recognizes apolipoprotein B of LDL and apolipoprotein E found on some, but not all, HDL. Within a species, a positive relationship may exist between HDL apolipoprotein E content and importance of HDL cholesterol as a precursor for steroidogenesis. A "HDL pathway" exists for uptake of sterol from HDL void of apolipoprotein E. The HDL receptor exhibits broad binding specificity. Unlike LDL, the HDL particle is not internalized, and cholesterol preferentially is taken up relative to other HDL constituents. In most species, lipoproteins, rather than de novo synthesis from acetate, contribute the majority of cholesterol used for steroid production. Trophic hormones increase lipoprotein binding, internalization, degradation and conversion of lipoprotein-derived sterol to steroids, effects that are mediate through cyclic adenosine monophosphate. Knowledge recently acquired regarding lipoprotein sterol utilization by the ovary may be useful in developing nutritional, pharmacological or endocrine manipulations that may positively affect cholesterol clearance by the ovary, steroidogenesis and reproductive performance.     

Plasma lipoprotein concentrations in the dog: the effects of gender,age, breed and diet

Earlier studies of canine lipoprotein metabolism have frequently not taken into account such variables as age, gender, lifestyle or feeding status. In the last years, many changes to lifestyle and feeding of dogs have occurred. In this study, C-tot, C-HDL, C-LDL, triglycerides and lipoprotein fractions were determined in 251 healthy dogs by means of enzymatic methods and through the electrophoretic technique. All data were analysed by multifactor anova test to determine which factors (age, gender, breed and diet) have a statistically significant effect (p < 0.05) on the determined parameter and subsequently Bonferroni’s test was applied where necessary. Gender, age, breed and diet can significantly affect lipid metabolism, in particular lipoproteins involved in cholesterol plasma transport; on the contrary, triglycerides are not influenced by the same factors. The most important observation about age is the high level of C-LDL in puppies under 1 year of age. The highest cholesterol concentrations are found in Rottweiler but high values of plasma cholesterol are found also in Pyrenees Mountain dog and a great level of C-LDL in Labrador. Diet has shown a great influence on lipidic metabolism: dogs fed with different high-quality dry foods had significant differences in plasma cholesterol values (C-tot, C-HDL, C-LDL,), in particular, dogs fed with a diet rich in fish and fish-by-products have shown the lowest levels of C-tot, C-HDL and C-LDL.     

鱼油在饲料中的应用研究

鱼油富含（ω-3多不饱和脂肪酸——二十碳五烯酸（EPA）和二十二碳六烯酸（DHA）,具有重要的营养生理功能,在饲料中已广泛应用。本文就鱼油的营养生理功能、在饲料中的应用、氧化及抗氧化等方面作一简要综述。     

L-肉碱的代谢及其在鱼类养殖应用中的研究进展

L-肉碱是一种广泛存在于动植物体及微生物体内的条件性必需营养素,其主要功能是作为转运脂肪酸的载体促进能量产生。近年来,L-肉碱作为饲料添加剂已逐步地应用于鱼类养殖生产中,在鱼类的生长、繁殖、免疫等方面发挥重要作用。本文在L-肉碱来源、转运、分布和代谢等基本信息的基础上,对L-肉碱的促生长、脂代谢调节及抗氧化等方面进行综述。