The effects of "Gasol" grain preservative dosages on the growth of Fusarium graminearum and the quantity of the toxin zearalenone

In earlier experiments regarding the effects of preservative "Gasol" (containing various acids and additional compounds and intended for whole grain preservations) in recommended dosages, prevents the growth of Fusarium graminearum and reduces the amount of zearalenone when added to milled grain. It was proved in the tests carried out that the smaller dosages of "Gasol" were sufficient for the prevention of growth of the fungus and reduction in quantity of zearalenone. The degree to which the toxin was destroyed depended on the dosage of the preservation. A dosage twice as strong as that recommended in the instructions for practice destroyed all the toxin formed in the grain. A very small dosage of "Gasol" (1/8 of recommended dosage) prevented the growth of the fungus and only slightly reduced the amount of toxin only at the beginning of the test. Later, the growth of the fungus was more vigorous and significantly more toxin was present in the treated grain than in the grain which had never been treated with the preservatives, it has been proved that the preservative     

Rejection by pigs of mouldy grain containing deoxynivalenol

SUMMARY: Weaner pigs on a farm near Beaudesert in south eastern Queensland refused to eat feed comprised largely of wheat and barley. Older pigs consumed small amounts and some prepubertal gilts subsequently displayed enlarged and reddened vulvas. Wheat, barley and triticale were grown on the farm during 1983, which was unusually and persistently wet. The wheat and triticale were harvested and stored for about 3 weeks with moisture contents above 14% before being fed. Samples of the wheat and triticale contained pale pink grains, which can indicate infection by the fungus Fusarium graminearum Schw. On analysis 2 mycotoxins known to be produced by F. graminearum were detected, deoxynivalenol (vomitoxin) which causes feed refusal and vomiting, and zearalenone which causes oestrogenic effects. Concentrations of deoxynivalenol in the wheat, triticale and barley were 34, 10, and < 0.1 mg/kg respectively. Concentrations of zearalenone were 6.2, 2.8 and 0.1 mg/kg respectively. Subsequently, F. graminearum was isolated from grains and crop residues. Although the wet weather contributed to F. graminearum infection of the crops before harvest, most of the toxins probably developed during storage.     

Survey of vomitoxin-contaminated feed grains in midwestern United States, and associated health problems in swine

During the 1981 corn harvest season in Illinois and surrounding states, cold wet weather enhanced the growth of Fusarium graminearum, with resulting contamination by vomitoxin and, to a lesser extent, zearalenone. Of 342 feed samples analyzed, 274 contained vomitoxin at a concentration ranging from 0.1 to 41.6 ppm (mean, 3.1 ppm) and 40 samples contained zearalenone at a concentration ranging from 0.1 to 8 ppm (mean, 0.66 ppm). Animal health problems and reduced growth performance were observed mainly in swine fed vomitoxin-contaminated rations. The predominant clinical complaints, in decreasing frequency were: reproductive problems (50%), feed refusal (43%), reduced weight gain (25%), diarrhea (17%), death (14%), and emesis (11%).     

有氧条件下污染禾谷镰刀菌的玉米蛋白粉品质变化规律和呕吐毒素的积累规律研究

本试验旨在研究有氧条件下接种禾谷镰刀菌后玉米蛋白粉品质变化规律和呕吐毒素(DON)的积累规律。采用1×10^5、1×10^6、1×10^7个/g禾谷镰刀菌接种量准确接种于水分含量为22%的玉米蛋白粉中,三角瓶有氧培养,通氧量为1020 m^2/m^3,培养温度为(25±2)℃,湿度为(75±5)%,培养60 d,测定玉米蛋白粉品质相关指标和DON积累规律。结果表明:禾谷镰刀菌接种量对为禾谷镰刀菌提供氮源的粗蛋白质、氨基酸含量和提供碳源的粗脂肪、淀粉、粗纤维含量以及品质评价指标酸价、蛋白质溶解度、能量变化均无显著影响(P>0.05)。氨基酸含量随着培养时间的延长呈二次曲线变化(P<0.01),粗脂肪、淀粉、粗纤维含量及蛋白质溶解度、能量随着培养时间的延长呈线性降低(P<0.01),酸价随着培养时间的延长呈线性增加(P<0.01)。禾谷镰刀菌接种量对品质评价指标霉菌总数变化有影响,不同禾谷镰刀菌接种量组霉菌总数随着培养时间的延长呈二次曲线变化(P<0.01)。DON与15乙酰基脱氧雪腐镰孢菌烯醇(15AC⁃DON)的积累规律均为0~10 d为禾谷镰刀菌产毒前期;11~15 d为产毒中期;16~60 d为产毒后期。综上,在有氧条件下,禾谷镰刀菌接种量对营养素变化无显著影响,对霉菌总数和毒素积累有影响,培养时间越长,禾谷镰刀菌接种量越高,品质越差;DON和15AC⁃DON有积累规律。     

甘肃中部地区禾谷镰孢的变异研究

为掌握禾谷镰孢在甘肃中部地区的分布及变异情况,从根部表现有坏死和叶鞘发褐的小麦幼苗的不同部位、小麦地土壤及玉米籽粒、玉米茎秆上分离禾谷镰孢,并以形态学为基础,参照Nelson分类系统进行鉴定。结果表明,在分离到的43个镰刀菌菌株中,有14个菌株经鉴定为禾谷镰孢,均从玉米茎秆上分离到,小麦根部、小麦叶鞘、小麦地土壤、玉米籽粒中分离到的镰刀菌中未见禾谷镰孢。将禾谷镰孢在特定条件下培养后,发现14个禾谷镰孢菌株产生子囊壳的数量不同,为2～90个。在以Fg16为引物的PCR反应中,随机选取的11个禾谷镰孢菌株都产生0.41kb的PCR产物,而6个对照菌株都产生0.50kb的片段,证明引物Fg16可以区分禾谷镰孢菌株群体的遗传多态性。以Tri13为引物的PCR反应显示,11个禾谷镰孢菌株以及3个中国对照菌株都产生脱氧雪腐镰刀菌烯醇(DON)毒素,而3个澳大利亚对照菌株产生雪腐镰刀菌烯醇(NIV)毒素。     

Toxinogenic vomitoxin-producing fusaria isolated from wheat

Out of the 25 strains of the genus Fusarium isolated from wheat visibly infested by moulds, three strains of F. graminearum were found to produce vomitoxin and zearalenone; the respective amounts of these toxins per 1 kg of wheat were 70, 100 and 600 mg vomitoxin, and 600, 400 and 250 mg zearalenone. The production of vomitoxin showed a marked decrease when the cultures were re-inoculated. An analytic determination of vomitoxin in cereals was worked out by the method of high-pressure liquid chromatography with a limit sensitivity of 20 micrograms vomitoxin per kg and by the method of thin-layer chromatography with a limit sensitivity of 100 micrograms vomitoxin per kg. The embryotoxicity of vomitoxin measured in chick embryos incubated for 40 hours was in the order of 1 microgram per embryo.     

Effects of graded levels of Fusarium toxin-contaminated wheat and of a detoxifying agent in broiler diets on performance,nutrient digestibility and blood chemical parameters

1. A growth experiment was carried out with male broilers from d 1 to d 35 of age in order to evaluate the effects of the addition of a detoxifying agent (Mycofix Plus, Biomin GmbH, Herzogenburg, Austria) at different dietary proportions of wheat (0, 16.5, 33, 49.5 and 66%) contaminated with Fusarium mycotoxins (21.2 mg of deoxynivalenol and 406 microg of zearalenone, ZON, per kg of wheat) on growth performance, nutrient and zearalenone balance and clinical-chemical parameters. 2. An increase in dietary mycotoxin concentration resulted in a linearly related decrease in feed intake, a slight decrease in weight gain and an improvement in feed to gain ratio. 3. Apparent protein digestibility and net protein utilisation were higher in diets containing exclusively Fusarium toxin-contaminated wheat than control diets. 4. The proportions of beta-zearalenol, alpha-zearalenol and ZON of total ZON metabolites in excreta of broilers fed on the diets containing the Fusarium toxin-contaminated wheat were approximately 3, 21 and 76%. 5. Serum antibody titres to Newcastle disease virus decreased in a linear fashion with increasing mycotoxin concentration in the diets, whereas other clinical-chemical serum parameters (liver cell and muscle cell necrosis indicating enzymes, haemoglobin, haematocrit, magnesium, inorganic phosphate) were not influenced by increasing Fusarium toxin concentrations. 6. Supplementation of the diets with Mycofix Plus decreased performance in a manner independent of mycotoxin concentration. Moreover, some clinical-chemical serum parameters were significantly altered due to Mycofix Plus but also independently of the dietary mycotoxin concentration.     

The occurrence of Fusarium varieties and their mycotoxins in silo corn. 3. The effect of silaging on the zearalenone content of CCM corn

The influence of silaging on zearalenone already formed and on the growth of Fusarium culmorum in naturally contaminated CCM maize was studied. The zearalenone content remained approximately constant (13.35 +/- 2.94 mg/kg, n = 59) over the whole test period (12 weeks), whereas Fusarium culmorum could not longer be detected after 11 days. Thus the hypothesis that zearalenone survives the silaging process unchanged is experimentally strongly supported. The study confirms the view that zearalenone detected in maize silages is probably already formed in the field or during intermediate storing. Relations between the fermentation process and the toxin content of the silage could not be ascertained.     

两种防霉剂抑制黄曲霉菌及禾谷镰刀菌的生长和饲料防霉效果研究

研究的主要目的是评估并比较丙酸钙复合型和高效复合型防霉剂抑制黄曲霉菌及禾谷镰刀菌的生长和饲料防霉效果。研究采用体外抑菌(禾谷镰刀菌F.0705和黄曲霉菌)试验和饲料破坏性试验两种方法进行。结果表明:两种防霉剂对禾谷镰刀菌(F.0705)和黄曲霉菌均有抑制作用,而且,随着防霉剂浓度的增大,其抑菌效果增强;从饲料破坏性试验来看:在第9 d和13 d采样时,两种防霉剂处理过的饲料霉菌总数极显著低于空白对照组(P<0.01),而且添加的防霉剂浓度越大,饲料中霉菌总数越少。总体来看,高效复合型防霉剂的抑制效果优于丙酸钙复合型。     

Fusarium crookwellense-produced zearalenone in maize stubble in the field

Waste grain and vegetative material (stems and leaves) collected from a maize field several months after harvest was analysed by bi-dimensional thin layer chromatography for the presence of aflatoxins, deoxynivalenol, ochratoxin A, sterigmatocystin, T-2 toxin and zearalenone. Deoxinivalenol (0.7 mg/kg) and T-2 toxin (4.1 mg/kg) were found in the grain and zearalenone (3.0 mg/ kg) was found in the stem and leaf. No other toxins were detected. The stubble was examined for the presence of potentially toxigenic Fusarium species, and F. poae, F. moniliforme var. subglutinans and F. crookwellense were isolated and identified. When these isolates were cultured on cracked corn, only F. crookwellense was found to produce micotoxins and then only zearalenone was detected. As corn stubble is commonly grazed in Argentina and in other countries, these findings identify a further source of mycotoxins that may adversely affect animal health and productivity.     

A sensitive bioassay for detection of dietary estrogens in animal feeds

Estrogen-responsive proliferation in the MCF-7 cell line was used as a bioassay for detection of dietary estrogens. The bioassay procedure was adapted to screen for estrogenic activity in feedstuffs that have been associated with hyperestrogenism in livestock. Methanolic feed extracts were added to the cell culture medium at microliter/ml concentrations for 4 days, after which the cell proliferation response was measured as DNA content. The half-maximal response for estradiol occurred at 2 pM, or 0.54 pg/ml. For zearalenone, a weaker estrogen, the half-maximal response occurred at approximately 200 pM, or 64 pg/ml. The bioassay was calibrated against a number of known estrogens (estradiol, diethylstilbestrol, zearalenone, zearalanol [cattle implant], beta-zearalenol, zearalane), including the naturally occurring phytoestrogens (formononetin, genistein, daidzein, biochanin A, and coumestrol). The estrogenic activity of feed samples was expressed as equivalents of zearalenone (ppm zearalenone) that would have to be present to equally stimulate proliferation of the MCF-7 cells. The sensitivity of the bioassay was 0.05-0.1 ppm equivalents of zearalenone in feed, well below the threshold level associated with reproductive problems. The feed additive melengestrol acetate (MGA) showed no estrogenic activity in this assay. Estrogenic activity of feed extracts was confirmed by competitive inhibition with the antiestrogens tamoxifen or LY156758 (keoxifene) to show that stimulation of growth by feed extracts was through an estrogenic mechanism. Confirmation of known estrogens was by tandem mass spectroscopy. The assay is a sensitive and reliable screening procedure for detecting estrogenic activity in feedstuffs.     

百香果茎基腐病病原鉴定及室内毒力测定

茎基腐病是百香果毁灭性病害之一。本研究结合症状观察、病原菌分离纯化、致病性测定和分子鉴定等手段,确定了病原种类,进而采用菌丝生长速率法和孢子萌发法对其进行室内毒力测定,以期筛选出高效防控药剂。结果表明：病原菌有典型的镰刀菌特征,其ITS序列与腐皮镰刀菌（Fusarium solani）的多条序列聚在同一分支上,相似性达100%,说明百香果茎腐病的病原为腐皮镰刀菌（Fusarium solani）。室内毒力测定的6种药剂中,250g/L升苯醚甲环唑乳油对菌丝生长的抑制效果最明显,EC50为0.3372 mg/L,其次是450g/L咪鲜胺水乳剂和70%甲基硫菌灵可湿性粉剂,EC50分别为0.4749 mg/L和0.7172mg/L;但镰刀菌孢子萌发测试表明, 450g/L咪鲜胺水乳剂浓度为9mg/L时的抑制效果最好,为74.78%,其次是70%甲基硫菌灵可湿性粉剂1400mg/L和250g/L苯醚甲环唑乳油250mg/L,分别为58.89%和33.67%,30%噁霉灵水剂效果最差,浓度为600mg/L时,抑制率接近于0。     

Bioactivation of zearalenone by porcine hepatic biotransformation

Zearalenone (ZEA) is a resorcylic acid lactone derivative produced by various Fusarium species that are widely found in food and feeds. The structure of zearalenone is flexible enough to allow a conformation able to bind to mammalian oestrogen receptors, where it acts as an agonist. Using oestrogen-dependent Human Breast Cancer (MCF-7) cells, the oestrogenic activity of zearalenone and its derivatives were compared using 17 beta-oestradiol as a positive control. The results obtained demonstrate that the oestrogenic potency of ZEA derivatives could be ranked in the following order: alpha-zearalenol > alpha-zearalanol > zearalenone > beta-zearalenol. Since pigs have been reported to be among the most sensitive animal species, biotransformation studies with pig liver subcellular fractions were conducted. These studies indicated that alpha-zearalenol is the main hepatic metabolite of zearalenone in pigs, and it is assumed that 3 alpha- and 3 beta-hydroxysteroid dehydrogeneases are involved in the hepatic biotransformation, since the formation of alpha-zearalenol and beta-zearalenol could be inhibited by prototypic substrates for either enzyme. The bioactivation of ZEA into the more active alpha-zearalenol seems to provide a possible explanation for the observed high sensitivity of pigs towards feeding-stuffs contaminated with the mycotoxin.     

Propionic acid preservation of corn following inoculation with molds and yeasts

In laboratory tests spores of 7 Fusarium species, 6 yeast species, and of the molds Paecilomyces varioti and Trichoderma viride were inoculated into propionic acid treated corn. The initial moisture content of the corn was adjusted to 19, 25, 32, and 40%, the propionic acid dosages being 0.3, 0.5, 0.7, and 1.0% respectively. By these treatments the growth of the inoculated fungi was inhibited for a storage of a least 6 months at 20 degrees C. The inhibition of growth was indicated by the decrease of viable mold count, the percentage of surface-sterilized kernels infected with fungi being 0% after 6 months. In addition, by the propionic acid treatment the production of zearalenone by two strains of Fus. culmorum and three strains of Fus. graminearum, and the production of T-2 toxin by two strains of Fus. tricinctum and one strain of Fus. sporotrichioides was inhibited. These results were obtained during an incubation period of 1-4 months using a temperature shift (20 and 10 degrees C). The propionic-acid dosage sufficient for the inhibition of the inoculated fungi was lower than that recommended in the literature for large-scale treatment of corn.     

Occurrence of Fusarium strains and their mycotoxins on corn silage. 6. Formation of zearalenone and trichothecenes (type A) by indigenous Fusarium isolates

A total of 399 indigenous Fusarium strains mainly isolated from silage maize were tested for the production of zearalenone and type A trichothecenes by thin-layer chromatography and biological assays. About 45% of the isolates examined were capable of producing different levels of zearalenone and trichothecene toxins on a cracked corn substrate. The majority of these strains (75%) produced zearalenone only and no trichothecenes type A. The results of the biological tests indicated a higher rate of toxin-positive extracts than chemical analysis. Isolates of nine out of seventeen Fusarium species examined produced one or several mycotoxins looked for. The most important toxin producers were F. culmorum and F. crookwellense (zearalenone) and F. sporotrichioides (trichothecenes type A), respectively. F. avenaceum, the species most frequently isolated from silage maize, produced neither zearalenone nor trichothecenes but avenacein Y a antibiotic compound. First results of a study of the production of type B trichothecenes have shown that indigenous F. culmorum isolates were capable of producing high levels of deoxynivalenol.     

赤霉菌含毒素代谢物对小黑麦愈伤组织和胚芽生长的影响

选用对赤霉病抗性水平不同的品种（系）和6个赤霉病菌株，采用双层培养技术，研究了赤霉菌含毒素代谢物对小黑麦愈伤组织和幼苗胚芽长度的影响。结果表明，和无毒素处理的对照相比，赤霉菌含毒素代谢物对愈伤组织生长有极显著或显著的抑制作用，而对幼苗胚芽生长有极显著或显著的刺激作用，田间对赤霉病（FHB）抗性差的品种分别受抑制程度最重和对刺激反应最迟纯。品种间、菌株间存在着极显著或显著差异，在幼苗胚芽长度上，发现品种和菌株间存在极显著的互作效应。分析后认为，在多菌株接种下，品种平均相对生长量（和对照相比）是一个更加可靠的抗性鉴定指标。     

玉米赤霉烯酮的污染和残留及其作用机制

玉米赤霉烯酮(ZEA)是由镰孢真菌产生的类雌激素毒素.本文综述了ZEA的污染现状及其在动物组织中的残留现状,并且总结了ZEA的可能作用机制.     

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.     

The occurrence of Fusarium varieties and their mycotoxins in silo corn. 2. The formation of zearalenone in the field by artificial infection of silo corn with Fusarium culmorum (W. G. Smith) Sacc

The formation of zearalenone in a maize plot artificially infected with Fusarium culmorum was studied. The zearalenone concentration steeply increased only in the 8th week after inoculation and reached a maximum value of ca. 7 ppm, whereas zearalenone could not be detected in the control variants. The crude nutrient and dry matter content was not significantly influenced by the fungal infection. The infected crop showed average ear dry weights distinctly lower than that of the control variants (P less than or equal to 0.001). Apart from zearalenone, the mycotoxin deoxynivalenol was qualitatively detected in the infected maize. The toxicological relevance of the ascertained zearalenone content with regard to the health of dairy cattle and pigs was discussed.     

Modified halloysite nanotubes reduce the toxic effects of zearalenone in gestating sows on growth and muscle development of their offsprings

Background: Zearalenone(ZEN) is an estrogenic mycotoxin that is primarily produced by Fusarium fungi and has been proven to affect the reproductive capacity of many species to varying degrees. The present experiment was designed to study the maternal persistent effects of zearalenone toxicity in gestating sows on growth and muscle development of their offsprings, and the alleviation of zearalenone toxicity by modified halloysite nanotubes(MHNTs).Methods: Eighteen sows were fed with one of three dietary treatments that included the following:(1) a control diet,(2) a contaminated grain diet(with 50 % moldy corn, 2.77 mg/kg ZEN), and(3) a contaminated grain diet(with 50 %moldy corn, 2.76 mg/kg ZEN) + 1 % MHNTs. Each sow was exclusively fed its experimental diets from 35 to 70 d of gestation at a total of 2 kg daily. Muscle samples were collected from six piglets per treatment at birth, weaning and finishing.Results: The results showed that feeding the sows with the ZEN-contaminated diets from 35 to 70 d of gestation decreased the ADG, ADFI and G:F of their offsprings(P 0.05). The muscle fiber numbers in the newborn, weaning and growing-finishing pigs and the muscle fiber diameters at birth and weaning were also decreased by maternal ZEN exposure(P 0.05). The expressions of IGF-I, IGF-II, Myf-5 and Mstn at birth and IGF-II, Pax7, Myf-5 and Myo D1 at weaning were altered by feeding gestating sows with ZEN-contaminated diets(P 0.05). The MHNTs reduced most of the ZEN-induced toxic effects: the ADG and ADFI on growth performance, the muscle fiber numbers at weaning and finishing and the muscle fiber diameters at weaning(P 0.05). The expression levels of IGF-II and Mstn in newborn piglets and IGF-II and Myf-5 in weaning piglets were also prevented by adding 1 % MHNTs(P 0.05).Conclusions: The present study demonstrated that the offsprings of sows fed with ZEN-contaminated diets from 35 to 70 day of gestation exhibited weakening on growth performance, physiological changes in their muscle fibers and alterations of m RNA expression in their muscle tissues, and also indicated that MHNTs prevented most of the ZENinduced weakening in the muscle tissues.