鱼粉或饲料中掺皮革粉的鉴别──铬测定法

直到1959年,三价铬被证实为葡萄糖耐量因子的有效成分以后,铬才被认为是人和动物所必需的微量元素之一.试验研究证明,胰岛素发挥作用必须有三价铬的参与;缺铬动物血液内胆固醇和血糖升高,易发生动脉粥样硬化;铬与蛋白质代谢和生长发育密切相关,缺铬后甘氨酸、丝氨酸、蛋氨酸等进入心肌的速率和数量减少,生长发育停滞角膜浑浊,死亡率高;铬对血红蛋白的合成和造血过程有促进作用.三价铬与六价铬在体内可以相互转换.而六价铬的毒性比三价铬毒性高1000倍.铬中毒可使粘膜组织充血、水肿和内脏器官出血,甚至死亡.     

如何鉴别掺假鱼粉

近年来,各地多次在国产鱼粉中检出蟹壳粉、尿素,在进口新西兰鱼粉中检出羽毛粉、皮革粉等掺假原料,给饲料厂带来重大损失。由于一般饲料厂没有相应的检测设备,只能用简单方法鉴别,现将识别方法介绍如下：一、按尿素的识别：部分进口及国产鱼粉掺入尿素,以提高其蛋白质含量,冒充高档鱼粉。鉴别方法有两种：①灼烧试验：将20克鱼粉放在干净的铁片上,用电炉加热至70t后,如散发出刺鼻的么味则极可能接A尿素。②尿素可与对二甲胺基苯申述反应生成有色化合物,其颜色的深浅度与样品中尿太仓量成正比,利用此性质配制尿素标准液,用分光…     

鱼粉真伪的鉴别技术

饲料加工厂及养鱼用户购买鱼粉经常遇到的一个难题,买回来的鱼粉一是鱼味不正常;二是混有各类有机杂质或黄沙类无机杂质。故此,在购买鱼粉时应注意以下营养指标:(1)水分:鱼粉含水量控制在12％以下,若水分含量过高,易使鱼粉发热自燃或腐烂变质。(2)粗蛋白质:可根据农业部颁布的鱼粉标准,按需求鱼粉的等级确定粗蛋白含量     

鱼粉真伪的鉴别技术

1感观鉴别1.1视觉 用肉眼观察鱼粉特有的肌肉纤维条纹的形状及数量、色泽、有无杂物。质量好的鱼粉外观颜色比较均匀,蛋白质含量越高,肉松越多。在放大镜下可见明显的肌肉纤维。但鱼粉色泽又与加工方法有关,一般脱脂后人工烘干的鱼粉色泽较深,而自然晒干的鱼粉色泽较浅。1.2嗅觉 优质鱼粉呈咸腥味。若有氨味、霉味、臭味或其它异味,表明鱼粉被掺假或变质。1.3触觉 优质鱼粉用手指捻后,质地松软显鱼松状。质次鱼粉或掺假鱼粉质地粗糙,通过指捻可以观察其硬度、粘稠度及异杂物。1.4味觉 新鲜鱼粉有鱼香味或干鱼片味,盐份高的鱼粉味咸…     

掺假鱼粉的鉴别与检测方法掺假鱼粉的鉴别与检测方法

鱼粉是生产配合饲料的主要原料之一,也是鱼类主要的动物蛋白源,因此,鱼粉质量的好坏,对饲养效果的影响相当大。根据多年的经验和从事饲料营养分析的经历,笔者总结出检测及鉴别掺假鱼粉的办法。一、鱼粉掺假的方式(一)优质鱼粉中掺入劣质鱼粉。把价低质劣的鱼粉掺入到优质鱼粉中以次充好,以劣充优,并以优质鱼粉价格出售。(二)鱼粉中掺入外来有机物。把低成本原料等外来有机物掺入鱼粉中,以假乱真。如将颜色与鱼粉相似的棉籽饼粉和菜籽饼粉或血粉掺入鱼粉中,使购买者难以辨认;将剧末粉及稻壳粉掺入鱼粉中,增加鱼粉的疏松度,用手摸起来与优质鱼…     

鱼粉掺假掺杂鉴别研究

<正>鱼粉是饲料生产中最重要的原料之一,由于渔业资源的逐年匮乏,价格一直高攀,导致市场上各种掺假掺杂现象层出不穷。对鱼粉掺假的鉴别方法进行研究,可以提升原料品控人员对鱼粉的品质判断的正确率,在对鱼粉的性价比进行分析时可得到较客观的结论。     

鱼粉掺假掺杂鉴别研究

鱼粉是饲料生产中最重要的原料之一，由于渔业资源的逐年匮乏，价格一直高攀，导致市场上各种掺假掺杂现象层出不穷。对鱼粉掺假的鉴别方法进行研究，可以提升原料品控人员对鱼粉的品质判断的正确率，在对鱼粉的性价比进行分析时可得到较客观的结论。     

感观鉴别掺假鱼粉的方法

鱼粉是高蛋白动物饲料,用于饲养畜禽,效果显著,受到用户高度重视。因为鱼粉价格较贵,有少数不法之徒贪图暴利,向鱼粉内掺杂各种异物,给用户造成损失。掺杂物种类很多,有棉籽饼、稻壳、菜籽饼、麦茨、羽毛粉、骨肉粉、血粉、尿素、氮肥、砂土、贝壳粉等。下面介绍一些感观鉴别方法:l、对棉籽饼、菜籽饼、稻壳、羽毛粉的鉴别。取50g样品放在24、40、60、100目筛中各筛1分钟,然后在光线好的地方观察。在40、60目筛上存有大量绒团,并有褐色小颗粒,证明有棉籽饼掺在鱼粉中;在60、100目筛上有胶状、半透明有光泽的黄色或棕黄色颗粒,证明掺有羽毛粉…     

甲鱼饲料用鱼粉优劣的鉴别

鱼粉是生产甲鱼饲料产品最重要的蛋白质原料,占了饲料原料比例约60%以上。鱼粉质量的好坏,对甲鱼饲料产品的质量影响很大。因此,正确鉴别和选择鱼粉不仅影响饲料产品质量,对企业的经济效益也有很大影响。以下就鱼粉种类、生产加工、检验和新鲜度指标分别介绍,以便业内人士了解影响鱼粉质量的因素,从而正确选择鱼粉。一、鱼粉种类甲鱼饲料中可以使用的鱼粉有两类,即白鱼粉和红鱼粉。1、白鱼粉目前,甲鱼饲料中使用的鱼粉主要是以冷水白肉鱼类生产,粗蛋白含量可高达68%～70%,也有的在62%左右。白鱼粉的价格昂贵,一般都比红鱼粉高出20%以上。从2…     

论鉴别鱼粉质量的简易方法

鱼粉在水产配合饲料中非常重要。是配合饲料最常用的优质动物性蛋白源．含有丰富的必需氨基酸,适口性好,消化率高。由于其用量大,价格高,所以掺假现象特别严重。饲料厂进购原料时．     

鱼粉在水产饲料中的应用研究

As a main protein source in aquafeeds, fish meal has been extensively studied. Fish sources, freshness, processing temperature, lipid quality and microbiological index are five main aspects of the evaluation of fish meal quality. This paper reviewed the researches on fish meal including the evaluation of fish meal quality, the use of fishmeal and the environmental problems. Biogenic amine is the main potential toxin in decomposed fish meal including mainly histamine, cadaverine, putrescine and tyramine and most studies showed that they could affect the fish growth performance and health. The determination of protein digestibility of fish meal includes pepsin-digestion method, animal test, capillary electrophoresis, etc. The content of phosphorus in fish meal and its utilization can introduce pollution to water bodies and the use of alternative protein and improvement of utilization of fish meal can help to reduce the pollution from fish meal.     

鱼饲料中添加鱼油的作用

鱼饲料中添加鱼油的作用夏传武（湖北省职工医学院,荆州市４３４０００）顾贫（湖北农学院,４３４１０３）油脂是饲料中的能量和维生素及必须脂肪酸的重要来源。发达国家普遍在饲料中添加油脂特别是鱼油来提高饲料效率。鱼油的价格与棕榈油、豆油、牛油近似,但使用效果...     

中国鱼粉鱼油来源及利用

鱼粉鱼油是渔业生产的重要原料,连接着海洋捕捞业与养殖业,是现阶段渔业转型工作的一个重要部分。中国自2000年以后鱼粉鱼油使用量在每年160×104 t左右,达到一个相对稳定的水平。通过梳理近10年中国鱼粉鱼油生产原料、产量和消耗情况,分析了中国鱼粉鱼油利用现状,提出了健全渔业捕捞相关法律法规、推动鱼粉行业绿色转型、加大水产动物营养生理与饲料的科研力度等方面的建议。     

玉米蛋白粉替代鱼粉对大菱鲆摄食、生长及体组成的影响

以鱼粉和玉米蛋白粉作蛋白源,配制6种等氮等能的饲料。其中5种饲料(C0、C12、C25、C38和C50.5)分别含有0%、12%、25%、38%和50.5%的玉米蛋白粉以替代相应的鱼粉蛋白。其余1种饲料(C50.5CAA)是在饲料C50.5基础上补充1.8%晶体氨基酸混合物(L-lysine:1.2%,L-arg:0.6%)。经7周的生长试验,结果表明随着饲料中玉米蛋白粉替代水平的升高,大菱鲆(12.51±0.02)g的摄食率、特定生长率、饲料效率和蛋白质效率均显著下降。饲料中玉米蛋白粉含量为50.5%时,大菱鲆摄食率显著低于其他处理组(P<0.05)。当饲料中玉米蛋白粉含量超过25%时,大菱鲆特定生长率显著低于对照组(C0)(P<0.05)。当饲料中玉米蛋白粉含量超过38%时,饲料效率和蛋白质效率与对照组(C0)相比显著下降(P<0.05)。C50.5CAA组的摄食率、特定生长率和蛋白质效率与C50.5组相比都有升高的趋势,但差异不显著。而饲料中添加晶体氨基酸显著提高了大菱鲆的饲料效率(P<0.05)。饲料中玉米蛋白粉替代鱼粉对大菱鲆鱼体水分、粗蛋白、粗脂肪及灰分含量均无显著影响。饲料中玉米蛋白粉替代鱼粉对大菱鲆血清甘油三酯和尿素氮含量也不产生显著影响,然而,随着饲料中玉米蛋白粉含量升高,血清总胆固醇含量显著下降(P<0.05)。     

Substituting fish meal with soybean meal in diets of juvenile cobia Rachycentron canadum

An 8-week feeding trial was conducted with cobia to determine the amount of soybean meal that could replace fish meal in formulated diets without reducing growth. Juvenile cobia (initial mean weight, 32 g) were fed 48% crude protein diets in which dietary protein was supplied by brown fish meal or a mixture of hexane extracted soybean meal and the fish meal, resulting in 10%, 20%, 30%, 40%, 50% and 60% of fish meal protein being replaced by soybean protein. The fish readily accepted all seven experimental diets and no fish died during the trial. Detrimental effects on growth performance were obvious when half of the fish meal protein was replaced by soybean protein. There existed a significant difference in fish weight gain, feed conversion ratio (FCR), protein efficiency ratio (PER) and net protein utilization (NPU) when the replacement level for fish meal protein was increased from 40% to 50%, indicating that up to 40% of fish meal protein can be replaced by soybean meal protein without causing reduction in growth and protein utilization. On the other hand, quadratic regression analysis shows a growth optimum at 16.9% replacement of fish meal protein by soybean meal protein. Lipid concentrations in the cobia muscle increased significantly as dietary soybean meal increased. Muscle concentrations of free threonine and histidine decreased as use of the soybean meal increased in the diets. Since methionine concentration in the test diets decreased from 2.52 to 1.36 g 16 g⁻¹ N as the soybean meal protein replacement level was increased from 0% to 60% while all other essential amino acids remained relatively constant, dietary requirement of methionine was calculated assuming it was equally available between the two proteins. The broken-line model analysis based on fish weight gain shows a breakpoint when dietary methionine+cystine concentration was 2.66 g 16 g⁻¹ N or 1.28 g 100 g⁻¹ diet.     

Partial replacement of fish meal by cottonseed meal and soybean meal with iron and phytase supplementation for parrot fish Oplegnathus fasciatus

Two consecutive feeding trials were conducted to determine the optimum dietary level of the cottonseed and soybean meal (CS) for replacement of fish meal (FM) in diets for juvenile and ongrowing parrot fish with or without iron and phytase. In experiment I, juvenile parrot fish (BW: 3.17 g) were fed one of six experimental diets for 12 weeks which were formulated to replace FM protein by equal proportion (1:1, w:w) of CS at 0, 10, 20, 30, 40, or 50% (designated as CS0, CS10, CS20, CS30, CS40, or CS50, respectively). In experiment II, ongrowing parrot fish (BW: 55 g) were fed one of five experimental diets for 9 weeks. The experimental diets were formulated to replace FM protein by CS at 0, 20, or 30% (designated as CS0, CS20, or CS30, respectively) and to include ferrous sulfate (0.1 and 0.2%) and phytase into the CS20 and CS30 diets (CS20 + Fe&P and CS30 +Fe&P, respectively). Results from the two feeding trials indicated that the CS could replace up to 20% FM protein in diets for juvenile parrot fish (3–22 g) and up to 30% in ongrowing (55–120 g) parrot fish. The supplemental effect of iron and phytase was not significant on growth performance. Total or each gossypol enantiomer concentration in the liver increased as the level of dietary cottonseed meal increased. However, gossypol in the liver of fish fed diets supplemented with iron was not detected. The dietary supplementation of CS significantly reduced the levels of plasma triacyglycerols and total cholesterol. The present study indicates that plant protein sources are better utilized in larger fish, and that up to approximately 30% FM protein could be replaced by CS with iron and phytase in the presence of supplemental lysine and methionine.     

一种高蛋白鱼粉的加工试验

近十年来,我国渔业得到持续、高速的发展。1980年,我国水产品总量为450万吨,199O年为1237万吨,到1996年已达2813．29万吨,跃居世界第一。1997年,水产品总量按FAO渔业统计标准已达到3601．78万吨,占世界水产品总产值的28％,表1为1995年到1997年不同产品的产量及相应的增长率。表1我国近几年水产的捕捞量及不同产品的加工量（吨）由上表可以看出,在各类制品的加工中,增长最快的是以低值小杂鱼为原料的鱼糜制品和饲料制品。随着海洋捕捞业的发展,海洋渔业结构发生了深刻的变化,高档海产品产量大幅度降低,低值鱼的比重不断增加,…     

Evaluation of a fish meal analogue as a replacement for fish meal in practical diets for Pacific white shrimp Litopenaeus vannamei

Three six‐week growth trials and a digestibility trial were conducted to evaluate a fish meal analogue (FMA) as a replacement for fish meal (FM) in shrimp feeds. Trials 1 and 2 evaluated and confirmed the potential of FMA supplementation (0, 48.5, 97, 145.5 and 194 g/kg) as a replacement for FM up to 200 g/kg without balancing for phosphorus (P) in practical diets for juvenile Pacific white shrimp L. vannamei. At the end of trial 1, shrimp offered diets containing 48.5 g/kg FMA exhibited significantly higher weight gain (WG) than those fed with the diet containing 145.5 g/kg FMA. At the end of trial 2, dietary FMA inclusion at 48.5 and 97 g/kg significantly improved WG and protein retention (PR), while reducing FCR and protein content of shrimp body compared to the diet containing 194 g/kg FMA. To determine whether P deficiency is the cause of reduced growth, the third trial was conducted utilizing equivalent diet but balanced for P. At the end of trial 3, shrimp fed diet containing 48.5 g/kg FMA+P showed significantly higher WG and PR than those fed diet containing 145.5 g/kg FMA+P. No decreasing trend of growth was detected in the diets containing FMA compared to the FM‐based diet. Apparent digestibility coefficients of dry matter, energy, protein and amino acids of FMA were determined using chromic oxide as an inert maker and the 70:30 replacement technique. The energy, protein and individual amino acid digestibility of FMA were significantly lower than those of soybean meal and FM which were run at the same time. Results of this work indicate that FMA can replace up to 200 g/kg FM in shrimp diets with supplemental inorganic P. Given the good growth across the range of inclusion without any indication of a growth depression, the low nutrient digestibility of FMA may be due to an atypical response or the product simply does not work with the testing technique.