Ochratoxin A: Carryover from animal feed into livestock and the mitigation strategies

This review aims to highlight the effects of ochratoxin A (OTA) in the feed of meat-producing animals. The accumulation of OTA in feed and its distribution in various farm animals were compared and evaluated. Primarily, the oral administration of OTA-contaminated feed and the predisposition in an animal''s vital organ were critically examined in this work. The collated reports show that OTA directly associated with endemic nephropathy and its high concentration leads to degeneration of liver cells, and necrosis of intestinal and lymphoid tissues. At present, limited reports are available in the recent literature on the problems and consequences of OTA in feed. Therefore, this review focused on the OTA carryover from feed to farm animals and the interaction of its secondary metabolites on their biochemical parameters. Hence, this report provides greater insights into animal health related to OTA residues in meat and meat products. This article also explores mitigation strategies that can be used to prevent the carryover effects of OTA in livestock feeds and the effects in the food chain.     

Mycobiota and Ochratoxin A in laboratory mice feed: preliminary study

The occurrence of mycotoxin-producing moulds in animal feed is a hazard for animals. When these undesirable substances contaminate laboratory animal feed, convey an additional problem in experimental animal assays confidence levels. The aim of this study was to evaluate fungal contamination and to determine natural occurrence of Ochratoxin A (OTA) in 31 samples. OTA is a mycotoxin produced by fungi of two genera: Penicillium and Aspergillus. OTA has been shown to be nephrotoxic, hepatotoxic, teratogenic and immunotoxic to a number of animal species and to cause kidney and liver tumors in mice and rats. In this preliminary study, feed mould counts ranged from 3 to 4.2 log₁₀ cfu/g (colonies forming units per gram). When these species are present, there is a significant risk of contamination with mycotoxins resulting in both acute diseases called mycotoxicoses and chronic conditions, often recognized as situations involving mycotoxins. The most frequent genus isolated was Cladosporium sp. (84%), followed by Aspergillus niger and Penicillium (81%) and Mucor sp. (77%). All rat feed samples were examined for OTA, using High Performance Liquid Chromatography (HPLC). The detection limit was 2.0 μg OTA kg⁻¹ and all samples revealed to be negative for this mycotoxin. These mycotoxicological researches put in evidence the importance of the use contaminant-free experimental animal feed in order to prevent any interference on the health of experimental animals and emphasizes the need for systematic control of the feed as a key issue in animal experimentation.     

The Fusarium toxins deoxynivalenol (DON) and zearalenone (ZON) in animal feeding

The contamination of cereal grains with toxic secondary metabolites of fungi, mycotoxins, is a permanent challenge in animal nutrition as health and performance of the animals may be compromised as well as the quality of animal derived food. Therefore the present article reviews the issue of mycotoxins in animal nutrition. As the Fusarium toxins deoxynivalenol (DON) and zearalenone (ZON) are of particular importance under the production conditions in central Europe and Germany, with respect to their frequent occurrence in toxicologically relevant concentrations, special emphasis is layed on those mycotoxins. The effects of DON and ZON on susceptible animals as well as management strategies to cope with the contamination of grain with those toxins are reviewed.     

2006~2007年中国饲料及饲料原料霉菌毒素污染调查报告

作者评估了2006年和2007年上半年我国饲料原料和全价饲料中6种主要霉菌毒素的检出水平和分布特点,得出如下结论：①我国饲料原料和全价饲料中超标率和检出水平最高的霉菌毒素是玉米赤霉烯酮、烟曲霉毒素和呕吐毒素（田间型毒素）。人们一直重视的黄曲霉毒素（仓储型毒素）超标率和检出水平均比较低;②饲料原料和全价饲料中多种霉菌毒素往往同时存在,由于不同毒素间具有协同作用,将加剧毒素的毒性作用和中毒症状的严重程度;③副产品原料,特别是玉米副产品如干燥酒糟（DDGS）和玉米蛋白粉中霉菌毒素的污染非常严重;④与单一能量和蛋白质饲料原料相比,全价饲料中的多种霉菌毒素的检出水平才是相对比较准确和客观的控制指标;⑤控制霉菌毒素危害的最经济有效的措施是控制原料质量和使用有效的霉菌毒素吸附剂。     

Mycobiota and mycotoxins contamination in raw materials and finished feed intended for fattening pigs production in eastern Argentina

The aim of the present study was to determine the mycobiota and natural levels of mycotoxins such as zearalenone, fumonisin B₁, aflatoxin B₁ and ochratoxin A present in raw materials and finished fattening pig feed. Samples were examined for total fungi and genera distribution. Zearalenone, FB₁, AFB₁ and OTA contamination were determined using high pressure liquid chromatography and thin layer chromatography. Milled maize and finished feed samples showed fungal contamination over than 1 × 10⁴ CFU/g. All samples contained at least one of the main mycotoxigenic genera Aspergillus, Fusarium and Penicillium. A. flavus and F. verticillioides were the most prevalent species. Only some Aspergillus section Nigri strains from suckling pig to growing pig samples were able to produce OTA. A. flavus strains from milled maize, wheat bran, suckling pig to growing pig samples were able to produce AFB₁. All samples were positive for FB₁. Sucking pig, piglet, growing and boar feed samples showed ZEA natural contamination. AFB₁ and OTA contamination were not detected. There was a 100% correlation between FB₁ and ZEA contamination in sucking pig, piglet, growing and boar feed samples; 50% piglet samples and 67% suckling pig samples showed ZEA levels over the recommended limits. The present study has shown the occurrence of two mycotoxins, FB₁ and ZEA in feed intended for fattening pig consumption. In animal production, the simultaneous presence of toxicogenic fungi and low dietary levels of mycotoxins in field conditions can cause possible health impacts and lost performance in pigs from feeding spoiled feeds.     

Potential of plant polyphenols to combat oxidative stress and inflammatory processes in farm animals

Polyphenols are secondary plant metabolites which have been shown to exert antioxidative and antiinflamma tory effects in cell culture, rodent and human studies. Based on the fact that conditions of oxidative stress and inflammation are highly relevant in farm animals, polyphenols are considered as promising feed additives in the nutrition of farm animals. However, in contrast to many studies existing with model animals and humans, potential antioxidative and antiinflammatory effects of polyphenols have been less investigated in farm animals so far. This review aims to give an overview about potential antioxidative and antiinflammatory effects in farm animals. The first part of the review highlights the occurrence and the consequences of oxidative stress and inflammation on animal health and performance. The second part of the review deals with bioavailability and metabolism of polyphenols in farm animals. The third and main part of the review presents an overview of the findings from studies which investigated the effects of polyphenols of various plant sources in pigs, poultry and cattle, with particular consideration of effects on the antioxidant system and inflammation.     

The role of mycotoxins in the health and performance of dairy cows

In comparison to monogastric species, ruminant animals are generally considered to be less susceptible to the adverse effects caused by contamination of feeds with mycotoxins. This is based on the assumption that the rumen flora degrade and inactivate mycotoxins, thus protecting the animal. A number of mycotoxins, however, resist rumen degradation, causing distinct clinical signs of intoxication. Moreover, due to their complex diet, dairy cows may be exposed to a varying number of mycotoxins, originating from different feed materials such as roughage and concentrates. Exposure to these complex mixtures of mycotoxins may result in unexpected health risks. Due to a pre-existing negative energy balance, cows in the transition period are considered to be particularly sensitive to the exposure to feeds contaminated with moulds, fungal spores and mycotoxins.     

饲料中的霉菌毒素及其防制措施

霉菌毒素是由真菌或霉菌产生的次级代谢产物,在动物体中,霉菌毒素的毒性是慢性的,很少引起动物死亡。但是霉菌毒素的存在降低了饲料的营养价值,以及动物的生产性能,从而影响生产力,且霉菌毒素在畜产品(肉、奶等)中的残留会给人类健康带来严重威胁。作者主要介绍了饲料中常见的霉菌毒素(黄曲霉毒素、赭曲霉毒素、玉米赤霉烯酮、脱氧雪腐镰刀菌烯醇、T-2毒素、伏马菌素等),以及其毒性和危害,并从预防与去毒两个方面,阐述了霉菌毒素的防制措施,进而减少霉菌毒素造成的危害。     

镰刀菌毒素对动物毒性作用的研究进展

镰刀菌是污染粮食和饲料的主要真菌菌属之一,可产生多种高毒性、低分子量的代谢产物,如玉米赤霉烯酮、脱氧雪腐镰刀菌烯醇、T-2毒素等,这些毒素严重威胁动物和人类的健康。摄入镰刀菌毒素可对动物造成多种毒性作用,包括生殖毒性、免疫毒性、肠道毒性、肝肾毒性、细胞毒性及致癌性等。不同类型镰刀菌毒素引起的毒性作用不尽一致,且不同毒素间存在互作效应。为此,本文对单一或混合镰刀菌毒素毒性的研究进展进行了总结和归纳,为镰刀菌毒素的深入研究提供参考和借鉴。     

Vomitoxin and amino acid supplements in rat feed

In Finland grain has during some years contained considerable amounts of mycotoxins depending on the weather conditions, harvesting and preservation methods. The most common of these mycotoxins are Fusariumtoxins: zearalenone and trichotechenes. The trichotechene group is large, but only a few of the toxins are of practical interest in that they cause health disorders to farm animals. The most common toxin of the trichotechenes is deoksinivalenol or vomitoxin (DON), which causes, especially in pigs, vomiting and reduction in feed palatability.     

Simultaneous detection of multiple mycotoxins in broiler feeds using a liquid chromatography tandem-mass spectrometry

Mycotoxins are secondary fungal metabolites that are typically present in grain and feed ingredients used for animal feeds. An analytical method using LC-ESI-MS/MS was developed to quantify nine mycotoxins, consisting of aflatoxin B₁ (AFB₁), AFB₂, AFG₁, AFG₂, T-2 toxin, deoxynivalenol (DON), nivalenol (NIV), zearalenone (ZEA) and ochratoxin A (OTA) in broiler feeds. In total, 100 samples of broiler feeds were collected from poultry farms in Central Thailand. The survey found that AFB₁ and ZEA were the most prevalent mycotoxins in the feed samples at percentages of 93% and 63%, respectively. The limit of detections (LODs) of investigated mycotoxins was 0.20–0.78 ng/g. AFB₂, DON, AFG₁, NIV and T-2 toxin were also detectable at low contamination levels with percentages of 20%, 9%, 7%, 5% and 1%, respectively, whereas OTA and AFG₂ were not detected in any of the feed samples. These results suggest that there is a very low level of risk of the exposure to mycotoxins in feeds obtained from broiler farms in Central Thailand.     

Contaminants in feed for food-producing animals

Outbreaks of Bovine Spongiform Encephalopathy (BSE) and food borne microbial infections, dioxin contaminated animal products, the presence of veterinary drug residues, microbial resistance to antibiotics, mycotoxins, agricultural and industrial chemicals, etc. are serious concerns for the food industry in many countries. Since the direct links between feed safety and safety of foods of animal origin are obvious, feed production and manufacture should be considered as an integral part of the food production chain. Industry is responsible for the quality and safety of food and feed that is produced. This paper is a brief review of some microorganisms as source of infections for farm animals that could result in human illnesses. These include Salmonella enterica, Bacillus anthracis, Toxoplasma gondii, Trichinella spiralis, prions, Listeria monocytogenes, EHEC, Campylobacter, Clostridium botulinum, Hog Cholera virus, Foot and Mouth Disease virus, etc. as well as other contaminants associated with animal feed such as mycotoxins, veterinary drugs, dioxins and PCB and Genetically Modified Organisms.     

Risk assessment of endocrine-active compounds in feeds

As a key element of the 'farm-to-fork' approach, an assessment of the safety of feed components should consider major long-term toxicological hazards, such as endocrine disrupting chemicals (EDCs). In this review, attention is given to endocrine-modulating trace elements (such as iodine and trivalent chromium) and their potentially sensitive subgroups as nutritional feed additives from the standpoint of farm animal safety and consumer exposure. Feedstuffs can be a major vehicle for persistent EDCs, such as polychlorinated biphenyls, and potential risks include fish farming and ruminants grazing in polluted areas. Limited data still exist on the feed-to-food transfer of other EDCs, such as brominated flame retardants. EDCs of vegetable origin (e.g. zearalenone and isothiocyanates) can have a greater adverse impact on farm animals than environmental xenobiotics but the risk of carry-over to consumers appears low. Topics for further research are suggested, including the need for more refined exposure data, characterization of biomarkers for long-term effects, xenobiotic-nutrient interactions and the search for novel feed ingredients that are less vulnerable to contamination.     

The significance of mycotoxin assimilation for meat animals

Mycotoxins may influence animal health and may be responsible for alterations in carcass composition and quality. Of major interest is the formation of residues in edible tissues, which had been demonstrated for the mycotoxins aflatoxin B1 and its metabolites, for ochratoxin A, zearalenone, as well as some trichothecenes. The amount of detectable residue depends on the initial feed contamination, duration of toxin exposure and persistence of the toxin within the animal the latter varying according to the species. Thus, residues of aflatoxins and ochratoxin A could be detected with a higher frequency than residues of trichothecenes which are rapidly metabolized and therefore only rarely contribute to a contamination of edible tissues. However, sufficient data for the evaluation of approximative carry over rates are not available for all mycotoxins. The majority of mycotoxins are heat tolerant and therefore a decomposition during cooking or processing is almost unlikely.     

Mycotoxins: Their implications for human and animal health

Abstract

Mycotoxins contaminate various feed and food commodities, due to the global occurrence of toxinogenic molds. They exert adverse health effects in human and animals. The nature of these toxic effects varies depending on the chemical structure of the toxin. The degree of these adverse effects is not only determined by the toxin concentration present in foods and feeds, but also by the time of exposure. Whilst in animals, next to acute intoxication, losses in productivity, reduced weight gain and immunosuppression are considered as most important feature of mycotoxicoses, genotoxic effects and the involvement of certain mycotoxins such as aflatoxin, ochratoxins and fumonisins in the etiology of human cancers have obtained particular attention. This implies that recent research activities concentrate on mechanistic aspects of mycotoxin‐ induced pathologies, rather than compiling analytical measures of mycotoxin concentrations in food and feeds.     

Mycotoxins: their implications for human and animal health

Mycotoxins contaminate various feed and food commodities, due to the global occurrence of toxinogenic molds. They exert adverse health effects in human and animals. The nature of these toxic effects varies depending on the chemical structure of the toxin. The degree of these adverse effects is not only determined by the toxin concentration present in foods and feeds, but also by the time of exposure. Whilst in animals, next to acute intoxication, losses in productivity, reduced weight gain and immunosuppression are considered as most important feature of mycotoxicoses, genotoxic effects and the involvement of certain mycotoxins such as aflatoxin, ochratoxins and fumonisins in the etiology of human cancers have obtained particular attention. This implies that recent research activities concentrate on mechanistic aspects of mycotoxin-induced pathologies, rather than compiling analytical measures of mycotoxin concentrations in food and feeds.     

Occurrence of on-farm risk factors and health effects of mycotoxins in dairy farms in Jordan

The aim of this study was to determine the occurrence of on-farm risk factors and health effects associated with contamination of dairy feeds with aflatoxins (AFs), zearalenone (ZEN), trichothecenes (T-2), deoxynivalenol (DON), and fumonisins (FB) in Jordan. A pre-tested and validated questionnaire was used to determine on-farm practices and health effects associated with high levels of mycotoxins. A total of 88 feed samples were collected from the 37 farms participating in the study and analyzed using commercially available ELISA kits. The mean total AF concentration exceeded the European Union (EU) limit in alfalfa (4%) and total mixed ration (TMR) (3%) samples. Similarly, levels exceeding EU limits were observed for T-2 in alfalfa (29%), TMR (30%), and corn silage (4%). The average concentrations of ZEN and FB were 300 ppb and 11,638 ppb, respectively, which were below the EU maximum limits in all feed samples examined. Intensive management system (OR?=?7.70), imported feed (OR?=?3.40), feed storage on the farm for more than 1-month duration (OR?=?7.90), and not using antitoxins (OR?=?2.30) were significantly (P?<?0.05) associated with high levels of mycotoxins in feed samples. A significant correlation (P?<?0.05) was evident between the presence of mycotoxins in dairy feed and feed refusal (R?=?0.70), low milk production (R?=?0.50), diarrhea problems (R?=?0.60), infertility (R?=?0.50), and repeated breeder problems (R?=?0.80). Results show that mycotoxin contamination in dairy feeds is a problem in Jordan, and appropriate measures need to be undertaken to reduce risks to human and animal health and improve production.

     

中国青贮玉米中霉菌毒素的污染情况分析与动物健康风险评估

为了探明中国青贮玉米霉菌毒素的污染状况,评价霉菌毒素对动物健康的风险隐患,分别在东北地区(黑龙江)、西北地区(内蒙古、山西)、黄淮海地区(河南、河北)、华中地区(江苏)、西南地区(贵州、四川)和西藏地区9省(自治区)28县主要生产基地采集全株玉米(90份)和青贮玉米样品(161份),共计251份,基于固相分散萃取-液相色谱串联质谱法,测定样品中黄曲霉毒素(AFs)、呕吐毒素(DON)、伏马毒素(FB)、玉米赤霉烯酮(ZEN)等12种霉菌毒素含量,并利用暴露评估进行动物健康风险评估。结果表明:①参照中国饲料卫生标准,测定样品ZEN超标率为1.19%。当青贮玉米作为泌乳期奶牛饲粮的主要粗饲料时,参照美国食品药品监督管理局(FDA)和欧洲食品安全局(EC)饲料安全标准,FB(FDA)和AFs(EC)的超标率分别为23.90%和13.94%。②全株玉米在青贮前和青贮后,霉菌毒素含量变化差异不显著(P>0.05)。③在黄淮海、华中和西南地区,青贮玉米霉菌毒素检出种类和含量相对较高,而在西藏地区含量相对较低。④当动物食用被霉菌毒素污染的青贮玉米时,动物的健康风险排序为:羔羊>犊牛>奶牛;在羔羊中,霉菌毒素的风险排序为:AFs>ZEN>DON>FB。综上所述,中国青贮玉米中霉菌毒素的超标率较低,污染情况相对严重的地区是黄淮海、华中和西南地区。在这些地区,如果青贮玉米作为泌乳期奶牛饲粮中主要粗饲料时,AFs和FB的超标风险较高;如果青贮玉米作为羔羊和犊牛饲粮中主要粗饲料时,AFs污染可能引起动物健康风险。     

Ochratoxin a contamination of cereal grains and coffee in Hungary in the year 2001

Ochratoxin A (OTA) is a nephrotoxic and carcinogenic mycotoxin, a secondary metabolite produced by mould fungi belonging to several Aspergillus and Penicillium species. It is formed during the storage of cereal grains and other plant-derived products. OTA ingested by humans and animals with the food or feed may exert deleterious effects on health. The purpose of this study was to investigate the ochratoxin contamination of the most important potential sources of OTA. The OTA content of cereal samples for human consumption (36 baking wheat, 16 wheat flour and 6 maize coarse meal samples) and feed grain samples (30 feeding wheat, 32 feeding maize and 20 feeding barley samples) collected in the mid-phase or at the end of the storage period and of 50 commercial coffee samples was determined. The analyses were performed by immunoaffinity column--high-performance liquid chromatography (IAC-HPLC). The limit of detection of the method was 0.1 ng/g. Of the wheat samples intended for human consumption, 8.3% contained OTA at 0.29 ng/g on the average (OTA ranges: 0.12-0.5 ng/g; Table 2). The OTA contamination of wheat flour and maize meal samples for human consumption was similar to that of the baking wheat samples. OTA contamination was found in 26.7% of the feeding wheat, 15.6% of the feeding maize and 35% of the feeding barley samples. The average values and the ranges of OTA levels found in the above samples were 12.2 and 0.3-62.8 ng/g, 4.9 and 1.9-8.3 ng/g, and 72 and 0.14-212 ng/g, respectively (Table 3). Sixty-six percent of the coffee samples were contaminated with OA (average level: 0.57 ng/g, ranges: 0.17-1.3 ng/g; Table 4). OTA contamination of baking wheat samples was found to be relatively low, presumably as a result of the favourable weather at harvest and the optimal storage conditions. Calculations made on the basis of the obtained results show that the daily OTA intake of an adult human from edible cereals is only 6.7 ng, while the amount taken up with coffee is 4.1 ng daily. The high prevalence and high levels of OTA contamination in feed grains can be explained by the unfavourable storage conditions, and this finding suggests that OA-related health problems may arise in animals, and that foods of animal origin may be contaminated with this mycotoxin.     

霉菌毒素对畜禽的危害及削减方法研究进展

霉菌毒素是由不同种属真菌产生的次级代谢物,其对多种动物（包括人在内）具有显著毒性效果,如降低畜禽生产性能、损害脏器功能、影响机体免疫功能、造成细胞和DNA氧化损伤,甚至导致动物死亡等。饲料及其原料霉菌毒素污染是一个广泛的、全球性的问题,既可在作物田间生长时产生,也可在仓储期间产生,给畜禽养殖业造成了巨大的经济损失,防控霉菌生长及去除饲料中霉菌毒素已成为国内外研究的热点。实际上,不同霉菌毒素对不同动物的损害具有差异性,而在畜禽养殖过程中添加适当物质（如蒙脱石和酶制剂等）可有效抑制霉菌毒素活性,缓解霉菌毒素的毒性。作者详细论述了玉米赤霉烯酮、烟曲霉毒素、呕吐毒素、T-2毒素、黄曲霉毒素和烟曲霉毒素对畜禽的危害,并从物理、化学、生物角度介绍了削减饲料及其原料中霉菌毒素的方法,旨在为合理有效防控霉菌毒素毒害及保障畜禽健康养殖提供参考。