Sequestering agents bind dietary aflatoxin B1 (AFB1) and reduce absorption from an animal's gastrointestinal tract. As a result, they protect an animal from the toxic effects of AFB1 and reduce transfer of the metabolite, aflatoxin M1 (AFM1), into milk. Three experiments, using late-lactation Holstein cows fed AFB1-contaminated feed, were conducted to evaluate several potential sequestering agents for their abilities to prevent or reduce the transmission of AFM1 into milk. Six agents previously tested in our laboratory for AFB1 binding in vitro were evaluated in these experiments. These were: SA-20, an activated carbon (AC-A); Astra-Ben-20, a sodium bentonite (AB-20); MTB-100, an esterified glucomannan (MTB-100); Red Crown, a calcium bentonite (RC); Flow Guard, a sodium bentonite (FG); and Mycrosorb, a sodium bentonite (MS). Five of the six sequestering agents significantly (P < 0.01) reduced AFM1 contamination of milk (AB-20, 61%; FG, 65%; MS, 50%; MTB-100, 59%; and RC, 31%); whereas, AC-A, activated carbon, had no effect on AFM1 transmission at 0.25% of feed. By the first milking (1 day after cows consumed contaminated feed), AFM1 appeared in milk, then reached maximum levels after three days, and was absent from milk within four days after AFB1 was removed from the feed. Sodium bentonites at 1.2% of feed showed good potential as AFB1 binders; MTB-100, a yeast cell wall product, was equally effective at 0.05% in feed. Potential AFB1 binding agents should be evaluated experimentally to demonstrate efficacy. Our data show that sequestering agents can reduce AFM1 in milk of cows fed AFB1-contaminated feed.

Fusarium ear rot and fumonisin contamination are serious problems for maize growers, particularly in the southeastern United States. The lack of maize genotypes highly resistant to infection by Fusarium verticillioides or to fumonisin contamination emphasizes the need for management strategies to prevent contamination by this mycotoxin. Information on the initial appearance of infection and fumonisin contamination of kernels and their increase over time is needed to determine if early harvest may be an appropriate control strategy. Maize ears from replicated studies at two locations in eastern North Carolina were harvested weekly, starting 2 weeks after pollination and continuing for 14 weeks. The percentage of kernels infected with F. verticillioides and the fumonisin contamination in the harvested samples were determined. Kernel infection by F. verticillioides and fumonisin contamination appeared as kernels neared physiological maturity and increased up to the average harvest date for maize in North Carolina. Beyond this date, the concentrations of fumonisin fluctuated. Under years conducive for fumonisin contamination, early harvest (greater than 25% grain moisture) may help reduce the level of contamination.

The individual and combined effects of aflatoxin and deoxynivalenol (DON) were evaluated in young broiler chickens (Hubbard X Hubbard). The experimental design was a 2 X 2 factorial with treatments of 0 and 2.5 micrograms of aflatoxin/g of feed (ppm) and 0 and 16 micrograms of DON/g of feed. The broilers were maintained on these dietary treatments from hatching to 3 weeks of age in electrically heated batteries with feed and water available ad libitum. The aflatoxin treatment significantly (P less than .05) decreased body weight; weight gain; increased the relative weight of the spleen, liver, and kidney; induced hepatic hyperlipemia; decreased activity of lactic dehydrogenase; and decreased serum levels of protein, albumin, and phosphorus. The toxicity of DON was expressed through reduced growth rate, increased feed conversion; increased relative weight of the gizzard, anemia, decreased activity of lactic dehydrogenase, and decreased serum triglycerides. The interaction between aflatoxin and DON was characterized by reduced growth rates; increased feed conversion, increased relative weight of the proventriculus, gizzard, spleen, liver, and kidney, anemia, hepatic hyperlipemia, decreased activity of alkaline phosphatase, glutamic oxalacetic transaminase, and lactic dehydrogenase, and decreased serum levels of protein, albumin, uric acid, cholesterol, triglycerides, and calcium. These data demonstrate that both aflatoxin and DON can limit broiler performance and adversely effect broiler health. The effects of the combination of aflatoxin and DON on broiler performance and health was more severe than the individual effects of these mycotoxins; however, the interaction was not severe enough to represent toxic synergy and can best be characterized as additive toxicity.

Fusaric acid is produced by several species of Fusarium, which commonly infect corn and other agricultural commodities. Since this mycotoxin may augment the effects of other Fusarium toxins, a gas chromatography/mass spectrometry method of analysis in feeds was developed. Fusaric acid was analyzed as the trimethylsilyl-ester from F. moniliforme-cultures, -contaminated corn screenings, and feeds toxic to livestock. The mycotoxin was found in all samples and ranged from 0.43 to 12.39 micrograms/g sample. Also, fusaric acid was tested for its neurochemical effects in the brain and pineal gland of rats. Animals were dosed intraperitoneally (100 mg/kg body weight) 30 min prior to the onset of the dark phase (lights out) and the effects were studied at 1.5, 3.5, and 5.5 h after treatment. Brain serotonin (5HT), 5-hydroxyindoleacetic acid (5HIAA), tyrosine (TYRO), and dopamine (DA) were increased (P < 0.05) by fusaric acid, and norepinephrine (NEpi) was decreased (P < 0.05). Analogously, DA in the pineal gland increased and NEpi decreased (P < 0.05). Pineal N-acetylserotonin (NAc5HT) was increased (P < 0.05), whereas pineal 5HT and its two major metabolites 5HIAA and 5-hydroxytryptophol (5HTOL) decreased (P < 0.05). Elevated brain TYRO and brain and pineal DA, with decreased NEpi, may be consistent with fusaric acid's partial inhibitory effect on tyrosine-hydroxylase and its inhibitory effect on dopamine-beta-hydroxylase, respectively. Elevated pineal Nac5HT is consistent with decreased pineal 5HT and the increased pineal DA, and support the dopaminergic stimulatory activity of the enzyme responsible for the conversion of 5HT to NAc5HT. This is the first report of fusaric acid's in vivo effect on pineal DA, NEpi, 5HT, and NAc5HT in rats, and a relation for the effects on TYRO, 5HT, and 5HIAA in brain tissue. The results indicate fusaric acid alters brain and pineal neurotransmitters and may contribute to the toxic effects of Fusarium-contaminated feeds.

In an experiment to determine methods of incorporating soft winter wheat into broiler diets, a significant increase in mortality was observed in broilers fed wheat in crumbled diets. This increase in mortality was associated with necrotic enteritis with Clostridium perfringens indicated as the causative pathogen and complicated by a coccidiosis outbreak. When yellow corn was used in the diet, mortality was 2.9%. Use of all wheat, ground with a hammer mill, increased mortality to 28.9%. However, roller mill-ground wheat diet resulted in a mortality of 18.1%. When the grain component was approximately 50% wheat and 50% corn, mortality was 12.6% for broilers fed hammer mill-ground wheat and 3.4% for roller mill-ground wheat. Grain and feed were tested for several mycotoxins. Low levels of deoxynivalenol were found in both corn and wheat diets, but no differences between the corn and wheat-based diets were found that would explain the incidence of enteritis.

pH close to the isoelectric point. Second step: absorption of the lipids and the formation of a complex precipitate by hydrophobicity. Third st,ep: resolubilization of the weaker hydrophobic components by the addition of 1 M NaCl and neutralization. These three steps may cause the foimation of the globulin precipitates with the hydrophobic interaction between the a and a ' subunit-rich proteins, which mainly consist of p5 and p6 and lipids. The effect of heterogeneity of P-conglycinin on the ASF2 formation was less than ASFl formatiop as judged by the subunit constitution ( Figure 5). It is believed that the isoelectric point of glycinin was pH 5.8-6.4 and P-conglycinin was pH 4. 8-5.8 (Thanh and Shibasaki, 1976), so that proteins with a slightly charged cation interacted with the C1-ion under the ASF2 conditions. These interactions perhaps weakened the hydrophobicity of the protein surface at pH 4.5. The reduced effect of hydrophobicity on the ASF2 formation may be due to these interactions. In the mixture of P-conglycinin and glycinin, glycinin which has weaker hydrophobicity (Table 11), showed less precipitates. Moreover, the isoelectric point of glycinin is further from pH 4.5 than that of P-conglycinin; therefore glycinin gave nearly no precipitate with the ASF2 condition. y-Conglycinin, present in 0-conglycinin, was selectively precipitated. The average hydrophobicity or y-conglycinin was stronger than @-conglycinin (Table 11).Reverse-phase thin-layer chromatographic analysis of rice culture extrads of seven zearalenone producing isolates of Fusarium revealed several more polar compounds similar to zearalenone in fluorescence characteristics and/or reaction to 4-methoxybenzenediazonium fluoborate and Fast Violet B salt spray reagents. Capillary gas chromatography/mass spectrometric analysis of these extracts revealed six estrogenic compounds not previously reported as naturally produced, namely cis-zearalenone, cis-azearalenol, cis-and trans-p-zearalenol, and a-and 8-zearalanol.

Fumonisin B1 (FB1) is a maize mycotoxin. In tortilla preparation, maize is treated with lime (nixtamalization), producing hydrolyzed FB1 (HFB1) due to loss of the tricarballylic acid side chains. This study determined the following: 1) whether nixtamalization by Mayan communities reduces total fumonisins, and 2) the steps in the process at which reduction occurs. Tortillas prepared by the traditional process contained FB1, FB2 and FB3 and their hydrolyzed counterparts. There were equimolar amounts of FB1 and HFB1 in the tortillas, but the total fumonisins were reduced 50%. The total FB1 plus HFB1 in the residual lime water and water washes of the nixtamal accounted for 50% of the total FB1 in the uncooked maize. HFB1 and FB1 were present in a 1:1 mol/L ratio in the water washes of the nixtamal, the masa dough and the cooked tortillas, whereas the ratio of HFB1:FB1 in lime water after steeping was 21. Water washes contained 11% of the FB1 that was in the uncooked maize. The results show that the traditional method reduced the total fumonisins in tortillas and reduced the sphinganine elevation (a biomarker closely correlated with fumonisin toxicity) in cells treated with extracts of tortillas compared with cells treated with extracts of contaminated maize.

One diastereomer of trans-zearalenol [2,4-dihydroxy-6-(6,10-dihydroxy-trans-1-undecenyl)-benzoic acid-y-lactone] was isolated from cultures of Fusarium roseum 'Gibbosum.' This strongly estrogenic metabolite was identified by analysis of its mass spectrum and its behavior in thin-layer, high-pressure liquid and gasliquid chromatographic systems. The concentration of zearalenol in cultures was 563 ,ug/g, or 7% of the 8,000-,ug/g zearalenone content, while the two diastereomers