Mycotoxins in fungal contaminated samples of animal feed from western Canada, 1982-1994.

Feed samples from 94 cases involving fungal contamination and suspected mycotoxicosis of farm animals in western Canada were examined during 1982-1994 to assess the incidence of mycotoxins. Samples were analyzed for aflatoxins, ochratoxin A, citrinin, sterigmatocystin, and the fungal estrogen zearalenone. Samples infected with Fusarium fungi were additionally assayed for nivalenol, deoxynivalenol, fusarenone-x, 15-acetyl-deoxynivalenol, diacetoxyscirpenol, HT-2 toxin, and T-2 toxin. Mycotoxins were found in 21 feed samples from 17 cases (18% of the reported cases), generally at levels far below those needed to induce symptoms under laboratory conditions. HT-2 toxin and other type-A trichothecenes were detected in 5 samples, deoxynivalenol and other type-B trichothecenes in 13, ochratoxin A in 5, and citrinin in 2. In 9 cases, symptoms observed in the animals were consistent with the known effects of the mycotoxin(s) found in the particular feed samples.     

Analysis of Canadian and Irish forage,oats and commercially available equine concentrate feed for pathogenic fungi and mycotoxins

Respiratory infections, recurrent airway obstruction (RAO) and exercise induced pulmonary haemorrhage (EIPH) are major causes of poor performance in horses. Fungi and mycotoxins are now recognised as a major cause of these conditions. The most notable fungi are Aspergillus and Fusarium. Fungal spores can originate from forage, bedding and feed and, in turn, these fungal spores can produce a series of mycotoxins as secondary metabolites.This study set out to ascertain the degree of fungal and mycotoxin contamination in feed and fodder used in Irish racing yards over a one-year period. Weather conditions in forage producing areas were sampled by Met Eireann and the Canadian Meteorological Service.Fifty per cent of Irish hay, 37% of haylage and 13% of Canadian hay contained pathogenic fungi. Of the mycotoxins, T2 and zearalenone were most prominent. Twenty-one per cent of Irish hay and 16% of pelleted feed contained zearalenone. Forty per cent of oats and 54% of pelleted feed contained T2 toxins.     

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。     

饲料中娄地青霉(P.roqueforti)的检测

饲料中霉菌及其毒素的污染严重影响畜牧生产和人类健康 ,娄地青霉 (P .roquefortin)是饲料中新近发现的产毒霉菌 ,特别是在青贮饲料中有较高的检出率。其所产毒素对动物有明显的毒性作用 ,值得重视。本试验检测了 1 1 1份饲料样品 ,分别来自德国和中国的猪场、牛场以及鸡场 ,包括玉米、玉米青贮、牧草青贮以及混合饲料和牧草在内的多种饲料。通过霉菌形态学检查 ,对上述样品进行了全面检测 ,确定饲料中霉菌的含量为 2 0 0～ 8 0 0CFU/g饲料 ,青贮料中的优势菌为娄地青霉     

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.

     

Mycotoxins and mycoflora in animal feedstuffs in western Canada.

Feed samples associated with 51 cases of suspected or potential mycotoxicoses of farm animals in western Canada were examined during a three year study. Ochratoxin A was detected in four cases, T-2 toxin and diacetoxyscirpenol in one, and sterigmatocystin in one. Samples examined for microflora associated with production of these mycotoxins contained Penicillium spp., Aspergillus ochraceus, Fusarium spp. and fungi of the Aspergillus glaucus group. Samples were analyzed for T-2 toxin and diacetoxyscirpenol only if Fusarium spp. were present. The first known incidence of suspected sterigmatocystin poisoning of poultry through feed ingestion has been encountered.     

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.     

Occurrence of mycotoxins in Polish animal feed in years 2006-2009

We performed a 4‐year survey (2006–2009, 1255 samples) of fungal secondary metabolites in feed material (cereal and corn grains) and feedstuffs (silages, mixed feeds). Five major mycotoxin groups were studied, including aflatoxins (AF), ochratoxin A (OTA), trichothecenes [deoxynivalenol (DON), nivalenol (NIV), T‐2 toxin, HT‐2 toxin], zearalenone (ZEA) and fumonisins (FUM). The metabolites were identified using HPLC methods with fluorescent, UV and MS/MS detection. Both immunoaffinity and SPE columns were used for sample preparation. In eleven samples, the concentration of several mycotoxins exceeded the recommended guidelines for feedstuffs. DON was detected at the highest concentration in the majority of analysed samples (cereal grains, silages and mixed feeds, maximum values ranged from 409 to 14 470 ng/g). Corn grains also contained other Fusarium toxins (FUM) at maximum levels ranging from 435 to 9409 ng/g. The highest average_positive concentration of the other trichothecenes (NIV, T‐2 and HT‐2 toxins) was <5.0–139 ng/g. ZEA was found at the highest concentration in corn grains and silages (maximum values ranging from 292 to 603 ng/g and 116 to 1150 ng/g, respectively). The highest average_positive concentration and the maximum level of OTA were detected in cereal grains (33.0 ng/g in 2009 and 760 ng/g in 2007, respectively). Less than 7% of the 557 samples were contaminated with AF at low levels (maximum of 0.61 ng/g). Our results support the need for further monitoring of mycotoxins in Polish feedstuffs and their components.     

Feasibility of serological bulk milk testing as a method for BVD surveillance

A commercial ELISA detecting antibodies against bovine viral diarrhoea Virus (BVDV) was analysed for its applicability for bulk-milk screening. Detection limits were analysed using native and concentrated milk samples (milk treated with rennet and ammonium sulfate precipitated) from 10 cows whose sera showed different reactivity levels in the ELISA and from two cows which gave birth to persistently infected calves during the last year. Further this and a second commercial ELISA were used to screen 591 randomly selected bulk-milk samples. To clarify discrepancies thirty-nine herds were included in a follow-up study. A second bulk-milk sample and serum samples from 10 young cattle of 6 to 28 month of age per herd were analysed for antibodies against BVDV. The results of this second testing and the detection of viremic animals in 4 herds confirmed the results from initial bulk-milk testing with both tests. The analysed test is suitable for bulk-milk testing although its application is limited by vaccination.     

Morphological and molecular response of small intestine to lactulose and hydrogen-rich water in female piglets fed Fusarium mycotoxins contaminated diet

Background: Following the intake of Fusarium mycotoxin-contaminated feed, small intestines may be exposed to high levels of toxic substances that can potentially damage intestinal functions in livestock. It is well known that Fusarium mycotoxins will lead a breakdown of the normally impeccable epithelial barrier, resulting in the development of a "leaky" gut. H2 administration with different methods has been proved definitely potentials to prevent serious intestinal diseases. The goal of this study is to investigate the roles of lactulose(LAC) and hydrogenrich water(HRW) in preventing intestinal dysfunction in piglets fed Fusarium mycotoxin-contaminated feed.Methods: A total of 24 female piglets were evenly assigned to 4 groups: negative control(NC) group, mycotoxincontaminated(MC) feed group, MC feed with LAC treatment(MC + LAC), and MC feed with HRW treatment(MC +HRW), respectively. Piglets in the NC group were fed uncontaminated control diet, while remaining piglets were fed Fusarium mycotoxin-contaminated diet. For the NC and MC groups, 10 mL/kg body weight(BW) of hydrogen-free water(HFW) was orally administrated to piglets twice daily; while in the MC + LAC and MC + HRW groups, piglets were treated with the same dose of LAC solution(500 mg/kg BW) and HRW twice daily, respectively. On d 25,serum was collected and used for biochemical analysis. Intestinal tissues were sampled for morphological examination as well as relative genes and protein expression analysis.Results: Our data showed that Fusarium mycotoxins induced higher serum diamine oxidase(DAO) activities(P 0.05), D-lactic acid levels(P 0.01), and endotoxin status(P 0.01), lower villus height(P 0.01) and ratio of villus height to crypt depth(P 0.05) in small intestine, greater apoptosis index and higher mRNA expression related to tight junctions(P 0.05). In addition, the distribution and down-regulation of claudin-3(CLDN3) protein in the small intestinal was also observed. As expected, oral administrations of HRW and LAC were found to remarkably provide beneficial effects against Fusarium mycotoxin-induced apoptosis and intestinal leaking.Moreover, either HRW or LAC treatments were also revealed to prevent abnormal intestinal morphological changes,disintegrate tight junctions, and restore the expression and distribution of CLDN3 protein in the small intestinal mucosal layer in female piglets that were fed Fusarium mycotoxins contaminated diet.Conclusions: Our data suggest that orally administrations of HRW and LAC result in less Fusarium mycotoxininduced apoptosis and leak in the small intestine. Either HRW or LAC treatments could prevent the abnormal changes of intestinal morphology and molecular response of tight junctions as well as restore the distribution and expression of CLDN3 protein of small intestinal mucosa layer in female piglets that were fed Fusarium mycotoxins contaminated diet.     

Zearalenone and deoxynivalenol mycotoxicosis in dairy cattle herds

Mycotoxin contaminations pose a growing problem in animal production from the economic and toxicological point of view. Clinical symptoms of mycotoxicosis are relatively unspecific, making the disease difficult to diagnose. This study presents a clinical case of dairy cattle infected with natural mycotoxins produced by fungi of the genus Fusarium (zearalenone [ZEA] and deoxynivalenol [DON]) in eastern Poland. In dead and infected cows, the presence of ZEA and DON was determined in the blood serum, significant changes were observed in blood morphological and biochemical profiles, extravasations and bowel inflammations were also observed. The results reported testify to an acute autoimmune process in the intestines as well as immunosuppression.     

Comparison of competitive ELISA, indirect ELISA and standard AGID tests for detecting blue-tongue virus antibodies in cattle and sheep

The performances of a competitive enzyme-linked immunosorbent assay (ELISA) using a group specific monoclonal antibody against bluetongue virus, an indirect ELISA and the standard agar gel immunodiffusion (AGID) test were compared in the detection of serum antibody against bluetongue virus. Test sera consisted of 1300 bovine, 530 ovine and 160 carpine samples from bluetongue-free areas of Canada, 605 bovine and ovine field samples from the USA and Barbados and 464 samples from 79 cattle and sheep experimentally infected with 19 South African and five USA serotypes of bluetongue virus. The diagnostic specificity of the competitive ELISA, as determined for the bluetongue virus-free cattle sera was superior (99.92 per cent) to that of the indirect ELISA (99.85 per cent) and the AGID (99.0 per cent). The specificities of the competitive ELISA for sheep (99.63 per cent) and goats (100.0 per cent) sera were also higher than those of the AGID test. The performance of the ELISA tests was similar whether a gamma-ray-irradiated (2.0 Mrad) or a non-irradiated bluetongue virus antigen preparation was used. The competitive ELISA results for bovine field sera from endemic areas demonstrated a relatively low level of agreement (92.04 per cent) with AGID test results, with 9.7 per cent false negatives. The possible presence in these sera of antibody to cross-reacting antigens or to other orbiviruses, eg, epizootic haemorrhagic disease virus, which react in the AGID but not in the competitive ELISA may account for this lack of agreement.(ABSTRACT TRUNCATED AT 250 WORDS)     

The use of near infrared transmittance kernel sorting technology to salvage high quality grain from grain downgraded due to Fusarium damage

The mycotoxins associated with specific Fusarium fungal infections of grains are a threat to global food and feed security. These fungal infestations are referred to as Fusarium Head Blight(FHB) and lead to Fusarium Damaged Kernels(FDK). Incidence of FDK 0.25% will lower the grade, with a tolerance of 5%FDK for export feed grain. During infestation, the fungi can produce a variety of mycotoxins, the most common being deoxynivalenol(DON). Fusarium Damaged Kernels have been associated with reduced crude protein(CP), lowering nutritional, functional and grade value. New technology has been developed using Near Infrared Transmittance(NIT) spectra that estimate CP of individual kernels of wheat, barley and durum. Our objective is to evaluate the technology's capability to reduce FDK and DON of downgraded wheat and ability to salvage high quality safe kernels. In five FDK downgraded sources of wheat,the lowest 20% CP kernels had significantly increased FDK and DON with the high CP fractions having decreased FDK and DON, thousand kernel weights(TKW) and bushel weight(Bu). Strong positive correlations were observed between FDK and DON(r = 0.90); FDK and grade(r = 0.62) and DON and grade(r = 0.62). Negative correlations were observed between FDK and DON with CP(r =-0.27 and-0.32);TKW(r =-0.45 and-0.54) and Bu(r =-0.79 and-0.74). Results show improved quality and value of Fusarium downgraded grain using this technology.     

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.     

Validation of a human progesterone enzyme immunoassay (EIA) kit for use on serum of cattle in Cameroon

A study aimed at validating a human progesterone enzyme immunoassay kit was carried out on cattle at Bambui, Cameroon. Progesterone ELISA Kits (EH-511) were obtained from Clinpro International. Forty-one cows were selected, of which 19 were pregnant and 22 within 14 days post partum. Blood samples were analysed and progesterone levels were deduced from a curve obtained from standard absorbance values (A ₄₅₀). Results show that 95.5% of postpartum cows had progesterone levels below 1 ng/ml, with the highest level being 0.75 ng/ml. The mean level was 0.5 ± 0.26 ng/ml. The cows in the ‘pregnant group’ had progesterone levels ranging from 3.5 to 17.5 ng/ml. This kit can be used for measuring progesterone levels in cattle. Levels of 1 ng/ml for two consecutive samples or one sample at or above 3 ng/ml are an indication of the presence of corpus luteum, while cows below 1 ng/ml will be in anoestrus.     

Occurrence of the fusariotoxins deoxynivalenol and zearalenone in Austrian feedstuff in the period from 1995 to 1999

3970 feed samples were analysed for the fusariumtoxins deoxynivalenol and zearalenone. 979 (24.6%) of the submitted feed samples from farms with case history (swine herds: decreased feed intake and daily weight gain, vomiting, cannibalism, impaired fertility, small litter size, weakness of newborn piglets, prolonged oestrus of sows; cattle: persistence of follicular ovarian cysts, enteritis, decreased slaughter weight, feed refusal). 74% of the samples contained cereal and corn ingredients respectively or were complete diet samples from swine herds. Based on economic losses the fusariumtoxin deoxynivalenol is most important in Austrian husbandry and particularly found in maize, cornsilage, wheat and oat.     

Determination of the median toxic dose of type C botulinum toxin in lactating dairy cows.

Because of the difficulty in identifying botulinum toxin in cattle, it is hypothesized that cattle are sensitive to levels of toxin below the detection limits of current diagnostic techniques (the mouse protection bioassay and the immunostick enzyme-linked immunosorbent assay [ELISA] for type C botulinum toxin). Using an up-down method for toxicologic testing, the median toxic dose (MTD50) for cattle was determined. Four lactating Holstein cows were dosed at 0.125 or 0.25 ng/kg with Clostridium botulinum type C toxin and failed to develop clinical signs of botulism during the 7-day observation period. Three cows given 0.50 ng/kg of toxin developed clinical signs of botulism. From these results, the MTD50 was calculated at 0.388 ng/kg (3.88 mouse lethal doses/kg) using the trim-logit method. These results suggest that cattle are 12.88 times more sensitive to type C botulinum toxin than a mouse on a per kilogram weight basis. The mouse protection bioassay and the immunostick ELISA for type C botulinum toxin failed to identify the presence of the toxin in the serum, blood, and milk samples taken from all 7 animals.     

Persistence of Neospora caninum-specific immunoglobulin G antibodies in bovine blood and lung tissue stored at room temperature.

Blood and tissue samples obtained at necropsy from carcasses showing varying degrees of postmortem decomposition are sometimes used as sources of antibodies for serological tests, primarily in studies involving wild animals or in examination of aborted fetuses. To test the persistence of antibodies in blood and lung tissue kept at room temperature (approximately 20degreesC) for up to 48 and 118 days, respectively, serum and lung fluid from Neospora caninum-infected and uninfected cattle were tested using an indirect N. caninum immunostimulating complex enzyme-linked immunosorbent assay (ELISA). Testing of selected samples was also performed using a commercial Neospora competitive ELISA. Despite severe changes in the gross appearance of the samples, the blood collected through venipuncture from live animals remained essentially sterile, whereas the pieces of lung tissue showed a variety of bacterial and fungal growth. Nevertheless, there was no obvious reduction in antibody levels in either the blood or the tissue samples during the 2 observation periods. This study indicates that specific immunoglobulin G antibodies may be remarkably stable in sterile blood and decomposed lung tissue.     

牛奶中霉菌毒素共污染及联合毒理效应

霉菌毒素是由镰刀菌、曲霉和青霉等丝状真菌产生的低分子质量次级代谢产物。食品和饲料中霉菌毒素的共污染现象广泛存在,深受各国相关从业者和研究人员的重视,但直到今天,有关霉菌毒素的联合毒理效应研究仍然有所欠缺,如低毒性长期暴露的体内试验如今仍然很少。目前,世界范围内相关标准和法规的建立普遍只关注于单独霉菌毒素的毒理效应。牛奶作为居民日常消费的主要产品,同时更是婴幼儿前期成长过程中重要的食物来源,其安全性尤为重要。本文综述了牛奶中霉菌毒素共污染及联合毒理效应的研究进展,可以为牛奶和奶制品中霉菌毒素共污染风险评估及相关标准的建立和完善提供参考。     

Occurrence of Coxiella burnetii in Polish dairy cattle herds based on serological and PCR tests

The aim of the research was to assess the prevalence of antibodies to Coxiella burnetii in dairy cattle herds in Poland and to compare the results of real-time PCR and ELISA tests performed on bulk tank milk (BTM) samples. In total, 2635 serum samples collected from 969 dairy cattle herds from all provinces were tested using ELISA. Additionally, BTM specimens from 101 herds were analysed by ELISA and real-time PCR targeting IS1111 element. Presence of anti-C. burnetii antibodies was confirmed in 25.39% of serum samples in 237 herds (24.46%) and the herd-level seroprevalence in Voivodeships varied from 2.5% to 61.4%. Moreover, 46 (45.5%) of analysed bulk tank milk samples gave postive result in ELISA and microbial DNA was detected in 40 (39.6%) of tested herds. The comparative analysis of ELISA and real-time PCR results obtained for BTM samples using the chi-square test showed statistically significant relationship between results of both methods.