Immunoenzyme detection of the mycotoxin, ochratoxin A]

Indirect, enzymoimmunological assays of the mycotoxin ochratoxin A were developed. In this technique a polyclonal (rabbit) antibody to ochratoxin A was used, along with the other, peroxidase-labelled (pig anti rabbit) antibody. The sensitivity of this method ranged around 75 pg of ochratoxin A per pit. The range of calibration curve was from 10 to 1000 pg per pit. The cross reactions with other ochratoxins made 1.4% (ochratoxin C). The ELISA test of ochratoxin A can be used as an expeditious screening method for a preliminary examination of the greater number of samples.     

Use of the radioimmunologic determination of ochratoxin A mycotoxin in the screening of foods and animal feed of plant origin--cereal type

Trials were conducted to verify a simple procedure of preparing food and feed samples of plant origin for the radioimmunological assay of ochratoxin A. All 27 food samples subjected to testing met the general hygienic regulations for foods (NPK - ochratoxin A 20 micrograms.kg-1), and so did all 23 samples of the tested feeds. The proposed method of sample preparation is not suitable for the examination of animal-origin foods because some proteins (albumin) might interfere.     

In vitro and in vivo protective effects of three mycotoxin adsorbents against ochratoxin A in broiler chickens

1. The objective of this study was to investigate in vitro and in vivo (in broiler chickens) ochratoxin A (OTA) adsorption efficiency of three different adsorbents: inorganic (modified zeolite); organic (esterified glucomannans) and mixed (inorganic and organic components plus enzymes).

2. The aim of the study was to investigate which of these adsorbents provided the best protection against the presence of residues of OTA in the pectoral muscle and liver of broilers given an OTA-contaminated diet. In addition, it was important to test and compare the results of adsorbent efficiency using two different in vitro methods.

3. The results from classical in vitro investigations carried out in the artificial intestinal fluid, showed that the inorganic adsorbent (Mz), exhibited the highest adsorption, having adsorbed 80.86 ± 1.85% of OTA, whereas average in vitro adsorption abilities of organic (30.52 ± 3.50%) and mixed (32.00 ± 2.60%) adsorbents were significantly lower.

4. In the investigation of absorption in everted sacs of broiler duodenal segments (Everted Duodenal Sacs Procedure), higher OTA adsorption in gut was exhibited by organic adsorbent, 74.26 ± 4.48%. Furthermore, the mean adsorption efficiency of mixed and inorganic adsorbent was 65.26 ± 4.76% and 45.75 ± 7.14%, respectively.

5. In the in vivo investigation, broilers were fed for 21 d on diets containing 2 mg/kg of OTA and supplemented with inorganic (Mz), organic (Ms) or mixed adsorbent (Mf) at the recommended concentration of 2 g/kg of feed. All three adsorbents significantly decreased OTA residue concentrations in the pectoral muscle and livers, but the order of effectiveness was mixed > organic > inorganic. The most efficient was the mixed adsorbent which decreased residue concentration by 72.50% in pectoral muscle and 94.47% in livers.

6. The Everted Duodenal Sac in vitro method provided results similar to those obtained in the in vivo study. However, further studies are required to investigate the efficiencies of adsorbents against various mycotoxins using this method.     

复方丹参滴丸药渣的饲料化利用研究

此研究通过对复方丹参滴丸药渣进行的毒理学试验、常规营养成分分析检测、加工试验、动物适口性试验和动物生产性能试验,验证了其饲用价值,得出了复方丹参滴丸药渣可以开发成为一种新的非常规动物饲料原料的结论。     

Preparation of the mycotoxin ochratoxin A for research and diagnostic purposes

The following fungal strains were tested for the production of the mycotoxin ochratoxin A: Aspergillus melleus (CCM F 802), Aspergillus ochraceus (CCM 8002) and Aspergillus ochraceus (CCM F 803). The strain Aspergillus melleus (CCM F 802) proved to be very suitable for the laboratory preparation of ochratoxin A. The mould was multiplied on a natural substrate for 14 days at the temperature of 28 degrees C and at 100% relative humidity. Ochratoxin A was extracted into organic solvents (chloroform + acetic acid), purified with aqueous alkaline solutions and by preparative thin-layer chromatography. The isolated mycotoxin was identified by physico-chemical methods. The amount of pure ochratoxin A isolated from 600 g of substrate was 305 mg.     

饲料中霉菌毒素的控制

世界上每年大约有25％的谷物遭受各种霉菌污染,因污染程度不同,造成不同地区损失差异较大。西方国家多对饲料中的黄曲霉毒素有规定,且丹麦不仅限制饲料中而且也检查肉品中的黄曲霉毒素。中国是霉菌毒素的重灾国。因为我们谷物生长条件不成熟,饲料原料收获及干燥过程中设备条件不够,管理不当及一些无法避免的原因如机器翻晒过程中的压碎造成霉菌污染程度的增加,以及养     

A screening method for simultaneous immunochemical detection of aflatoxins and ochratoxin A in cereals and feed]

An immunochemical method was proposed for simultaneous determination of aflatoxin and ochratoxin A with the use of mixed solutions of the following reagents: standards of both mycotoxins, antiserums against the mycotoxins, and radioligands of 125I-aflatoxin B1 and 125I-ochratoxin A. The result of the analytical procedure is the value of concentration of the aflatoxin + ochratoxin A sum in the sample. The procedure needs half the amount of reagents as separate determination of each of the two mycotoxin, and is far less laborious. The proposed simultaneous immunoanalysis is suitable for large-are inspection of grain and feed safety from the viewpoint of aflatoxin and ochratoxin A levels.     

利用高效液相色谱法测定饲料中的赭曲霉毒素

霉菌遍布世界各地,种类繁多,依生活习性,分为仓储霉菌和田间霉菌。仓储霉菌是指储存的原料和饲料在适宜的温度、湿度下产生的霉菌,最适宜的生长温度为25￣30℃,相对湿度为80%￣90%。赭曲霉毒素(ochratoxin A)是温暖地区最重要的仓储毒素,广泛存在于玉米、大麦、小麦和饲料中,麸皮的污染高于整粒谷物。广东地处亚热带,温湿度十分适宜赭曲霉菌的生长,据调查发现该毒素污染在原料和配合饲料中大量存在。赭曲霉毒素危害很大,致癌性极强。据报道,每千克饲料中含有0.2￣0.3g,就可使鸡中毒,最常见的临床表现有:钙磷吸收障碍、骨骼脆弱、蛋壳钙化不…     

饲料中霉菌毒素的危害及其预防

饲料中霉菌毒素的污染及其所造成的危害目前仍是养殖者易于忽略的问题,且容易与其它疾病产生混淆。目前饲料工业和养殖业的着重点是抑霉、杀霉,饲料及其饲料原料无肉眼可见的霉变即可,然而霉菌毒素是肉眼看不见的,它的产生至今仍是全世界畜禽及谷类饲料安全无时不存在的自然威胁,它的来源、生成及其特性导致了一系列的困扰,比如,饲料配方不变,饲料品质却出现时好时差的情况;免疫程序不变,疫苗按时接种,可是畜禽抗体水平上不去;畜禽的生产性能下降、易感性提高、疾病频频发生等等一系列的问题。本文就霉菌及其霉菌毒素的产生、来源、危害和预…     

Effect of three mycotoxin adsorbents on growth performance, nutrient retention and meat quality in broilers fed on mould-contaminated feed

1. A study was conducted to investigate the effects of an esterified glucomannan (EGM), a hydrated sodium calcium aluminosilicate (HSCAS) and a compound mycotoxin adsorbent (CMA) on performance, nutrient retention and meat quality in broilers fed on mould-contaminated feed. Mould-contaminated diets were prepared by replacing half of the non-contaminated maize in the basal diets with mould-contaminated maize, which contained 450·6 μg/kg of aflatoxin B1, 68·4 μg/kg of ochratoxin A and 320·5 μg/kg of T-2 toxin. 2. The mould-contaminated diet significantly decreased body weight gain (BWG) between 10 and 21 d, feed intake (FI) between 35 and 42 d, the apparent retention of crude lipid and phosphorus, and the lightness (L*) value of breast and thigh muscle. It also significantly increased the redness (a*) and yellowness (b*) value in breast muscle and the b* value in thigh muscle. 3. The addition of 0·2% HSCAS significantly increased FI between 35 and 42 d and the apparent retention of phosphorus. Supplementation with 0·1% CMA in the contaminated diet significantly improved BWG from 10 to 21 d, and increased FI from 35 to 42 d and from 10 to 42 d. CMA also significantly increased the apparent retention of crude lipid, crude protein, ash and phosphorus. All three mycotoxin-adsorbent treatments significantly improved the L* values of breast and thigh muscle when compared with the mould-contaminated group. Supplementation with 0·1% CMA in the contaminated diet significantly decreased b* value and improved tenderness in thigh muscle. 0·05% EGM significantly decreased b* value of thigh muscle compared to mould-contaminated group. 4. The results indicated that mycotoxins in contaminated feed retard growth, nutrient retention and meat quality, whereas the addition of 0·05% EGM, 0·2% HSCAS or 0·1% CMA prevents the adverse effects of mycotoxins to varying extents, with 0·1% CMA being the most effective adsorbent treatment.     

畜牧场和饲料厂的饲料霉菌毒素污染情况检测

我国是饲料生产大国 ,配合饲料产量居世界第二位 ,每年由于饲料霉变所造成的损失十分巨大。广东地处亚热带 ,温度、湿度十分适宜霉菌生长。近年来 ,为更好地进行动物健康与安全管理系统建设和对广东省各地使用畜禽饲料受霉菌毒素污染的情况作进一步的了解 ,我们在 1 999～2 0 0     

A multi-strain probiotic administered via drinking water enhances feed conversion efficiency and meat quality traits in indigenous chickens

Whereas the use of probiotics is commonplace in commercial production of improved chicken strains, little is known about the impact of these live microbial feed additives in indigenous chickens in South Africa. This study investigated the effect of a multi-strain probiotic (containing Bacillus safensis, Bacillus subtilis, Bacillus megaterium and Cupriavidus metallidurans, total bacteria number was 1.4 × 10⁸ cfu/mL), administered via drinking water, on growth performance, blood parameters, and carcass and meat quality characteristics of Potchefstroom koekoek cockerels for a period of 12 weeks. A total of 140 five-week-old cockerels were randomly allocated to 4 experimental diets formulated to have similar energy and protein levels as follows: 1) negative control diet (CON; commercial chicken grower diet without both antibiotics and probiotics), 2) positive control diet (ANTIB; commercial chicken grower diet with antibiotics [0.05% Coxistac and 0.04% olaquindox] but no probiotics), 3) negative control diet plus 2.5 mL of probiotics per litre of water (PROB25) and 4) negative control with 5.0 mL of probiotics per litre of water (PROB50). There was a significant (P < 0.05) week and diet interaction effect on average weekly feed conversion efficiency. At 9 weeks of age, cockerels in PROB50 group had higher (P < 0.05) feed conversion efficiency than those in CON and ANTIB groups. However, 14-week-old cockerels in PROB50 group had lower (P < 0.05) feed conversion efficiency than those in ANTIB group. Treatments had no significant (P > 0.05) effect on overall feed intake, overall weight gain and haemato–biochemical parameters of cockerels. Gizzard and spleen weights were similar (P > 0.05) in PROB50, CON and PROB25 groups. Cockerels in PROB50 group had shorter (P < 0.05) small intestine than those in CON and PROB25 groups. Cockerels in PROB50 group had larger (P < 0.05) breast weight than those in PROB25 group. Cockerels in ANTIB and PROB50 groups had greater (P < 0.05) wing and thigh weights than those in CON and PROB25 groups. Shank weight was similar (P > 0.05) in PROB50, CON and ANTIB groups. Meat pH measured after 24 h of slaughter was the highest (P < 0.05) in CON and ANTIB groups followed by PROBO25 and PROB50 groups. Cockerels in CON group had lower (P < 0.05) cooking losses than those in ANTIB, PROB25 and PROB50 groups. It was concluded that probiotics can be used in place of prophylactic antibiotics in Potchefstroom koekoek cockerels.     

饲料中霉菌霉素的检测与控制

霉菌毒素是真菌的次级代谢产物，真菌代谢产物中的有毒物质统称为霉菌毒素。1960年英国“火鸡X病”爆发，世界开始注重对霉菌毒素中毒的彻底调查，现已知有300多种真菌可产生毒素。火鸡X-病的重要特征是，感染的动物不仅仅会受到黄曲毒素中毒的伤害，更常会继发其他多种病原感染，如沙门氏菌和大肠杆菌，这些继发感染常使症状显得更加复杂，从而导致诊断上的     

加强饲料安全管理提高畜产品质量

随着人民生活水平的不断提高,无污染、无残留和无公害的安全绿色食品已初步成为人们一种新的消费时尚,这对畜产品的生产同样提出了更高的要求。如何生产出让人们放心的安全的畜产品呢?首先必须从源头抓起,严把饲料生产关。畜禽的生产潜力是建立在“健康”基础上的,     

饲料中霉菌毒素的检测与控制

1霉菌毒素的特点及检测方法 霉菌毒素是真菌的次级代谢产物,真菌代谢产物中的有毒物质统称为霉菌毒素.1960年英国"火鸡X病"爆发,世界开始注重对霉菌毒素中毒的彻底调查,现已知有300多种真菌可产生毒素.火鸡X-病的重要特征是,感染的动物不仅仅会受到黄曲毒素中毒的伤害,更常会继发其他多种病原感染,如沙门氏菌和大肠杆菌,这些继发感染常使症状显得更加复杂,从而导致诊断上的失误或延误.现在已取得的共识是,由不同的霉菌毒素造成的中毒会导致动物免疫功能受到抑制,从而使动物对传染病病原的易感性增加,甚至一些对健康动物不具感染力的病原也会因霉菌毒素中毒而使动物发病.另外,轻度霉菌毒素污染的饲料其营养价值也会遭到破坏,饲料适口性明显下降,对动物的健康产生潜在的威胁.     

饲料中赭曲霉毒素的危害和监控

赭曲霉毒素A(OchratoxinA ,OA)是由曲霉菌属和青霉菌属几种菌产生的次生代谢产物,动物试验表明对肾脏、肝脏等具有较强的毒性。赭曲霉毒素广泛分布于饲料及饲料原料中,被摄食后累积在畜、禽体内,通过食物链对人类健康构成威胁。许多国家对其制定了最高允许量,并建立了监控检测体系。随着我国加入WTO ,建立自己的质量标准以监控饲料中赭曲霉毒素A是必要的。1　危害1 1　赭曲霉毒素A的毒性　赭曲霉毒素包含了7种结构类似的化合物,其中以赭曲霉毒素A的毒性最强。赭曲霉毒素A具有烈性的肾脏毒和肝脏毒,在自然界中低浓度存在时主要侵袭肾脏…