Winston M. Hagler

Aflatoxin binders II: reduction of aflatoxin M1 in milk by sequestering agents of cows consuming aflatoxin in feed.

Sequestering agents bind dietary aflatoxin B1 (AFB1) and reduce absorption from an animals 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 forAFB1 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); RedCrown®, 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 asAFB1 binders; MTB-1OO, a yeast cell wall product, was equally effective at 0.05% in feed. PotentialAFB1 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.

Aflatoxin Binders I: In vitro binding assay for aflatoxin B1 by several potential sequestering agents

Nine potential proprietary sequestering agents consisting of 4 activated charcoals, 3 sodium bentonites, a calcium bentonite, and an esterified glucomannan were compared in a novel in vitro assay for aflatoxin B1 (AFB1) binding. Agents were evaluated in 10% methanol prepared as 1% stirred suspensions at pH 3, 7, 10 and pH-unadjusted, with or without AFB1 at 5 μg/ml. All nine agents bound more than 95% of the 5 μg of AFB1 in solution, regardless of pH. The sodium bentonites bound 98, 95, and 98% of the AFB1. The four activated charcoals bound over 99%, the calcium bentonite bound 98%, and the esterified glucomannan bound 97% of the AFB1 in solution. The results suggested that the sequestering agents tested here had sufficient potential to bind AFB1 at pH values commonly found in the gastrointestinal tracts of ruminants and other animals.

Analysis of some metabolites of t-2 toxin, diacetoxyscirpenol and deoxynivalenol by thermospray high-performance liquid chromatography—mass spectrometry

Detection and identification of mycotoxin metabolites is a very challenging task. In order to achieve adequate sensitivity and specificity an analytical technique must overcome serious matrix interferences. Gas chromatography-mass spectrometry (GC-MS) which has the sensitivity and specificity to detect and identify mycotoxin metabolites requires hydrolysis of conjugated metabolites as well as derivatization. Thermospray high-performance liquid chromatography-mass spectrometry (HPLC-MS) offers the sensitivity, specificity, and structural information to detect and identify some mycotoxin metabolites in fecal and urine samples without derivatization. The mycotoxins evaluated in this study include deoxynivalenol (DON), T-2 toxin, and diacetoxyscirpenol. The de-epoxy and hydroxy metabolites of each toxin and the glucuronide conjugate of DON were isolated, extracted, and analyzed to detect their occurrence in animals. The thermospray mass spectra of the toxins showed an [M + H]+ ion and numerous structurally significant fragment ions in the positive ion detection mode. Negative ion detection exhibited primarily [M + acetate]- cluster ions with less fragmentation than observed by positive ion detection. The operation of the interface in the filament-on mode greatly increased the sensitivity in both positive and negative ion detection mode. Detection limits of 50-500 pg injected on column are obtained for these toxins and their metabolites using multiple ion detection. The urine and fecal extracts from rats, hens, and cows did not interfere with the HPLC-MS analysis for the specific metabolites or the glucuronide conjugate.

Acute Toxicity of Cyclopiazonic Acid in Selected Avian Species

Cyclopiazonic acid (CPA), a toxic indole tetramic acid with a molecular weight of 336.1, was first isolated and identified as a metabolite of Penicillium cyclopium Westling (Holzapfel, 1968). Several species of Penicillium and Aspergillus have been shown to produce CPA, including A. flavus (Dorner, 1983; Dorner et al., 1984; Gallagher et al., 1978; Holzapfel, 1968; Le Bars, 1979; Leistner and Pitt, 1977; Luk et al., 1977; Ohmono et al., 1973). Both peanuts and corn may be naturally contaminated with CPA and aflatoxin Bi (Gallagher et al., 1978; Lansden and Davidson, 1983). P. camemberti Thom, used in the commercial production of cheeses such as Camembert and Brie, was discovered to produce CPA (0.1 to 1.5 µg/g) in the mycelial crust but not in the interior of these cheeses (Le Bars, 1979).

Mycotoxins in North Carolina 1985 Crop Soybeans. I. Zearalenone and Deoxynivalenol in Soybeans and Soybean Meal

Soybean meal is the most important source of protein in animal feeds in the United States. Soybeans (Glycine max L.) and soybean meal have been perceived to be poor substrates for fungal growth. They have enjoyed the reputation of being resistant to contamination with mycotoxins, particularly aflatoxins and zearalenone (Shotwell et al., 1969; Eugenio et al., 1970), in comparison to corn, wheat, sorghum, and other feed grains. Thus, commercial soybean products have been thought to be very low in or free from fungal metabolites.

Conversion of Aflatoxins to Bisulfite Adducts for Quantitation and Confirmation

Aflatoxins and metabolites of aflatoxins are common natural contaminants of food products such as corn, peanuts, liver, and milk (Rodricks and Stoloff, 1977; Wong and Hsieh, 1978; Stoloff, 1980; Stoloff et al., 1981). Detection of these potently toxic and carcinogenic compounds at the parts-per-billion level or even lower in a variety of complex matrices challenges the analytical chemist to continually improve and expand the repertoire of analytical techniques.

Survey of Commercial Dog Foods for Aflatoxin B1 and Zearalenone

Mycotoxin contamination of grain, peanut, and soybean crops, while a recurrent problem, varies in severity from year to year due to environmental factors which modulate susceptibility of host plants to fungal pathogens (Council for Agricultural Science and Technology, 1989). Improper storage of crops, including allowing insect outbreaks in storage facilities, also plays an important role in mycotoxin contamination of grain (Council for Agricultural Science and Technology, 1979). Because plant products are used as protein and carbohydrate sources in commercially prepared animal feeds, mycotoxin contamination of prepared pet foods may occur.

An Epidemiological Study of the Association Between Delayed Estrus in Swine and Low Levels of Aflatoxin B1, in Naturally Contaminated Feed

Mycotoxins are secondary metabolites of fungi found as contaminants of feed grains. Some mycotoxins, such as aflatoxin B1 (AFB1), zearalenone (ZE) , deoxynivalenol, ochratoxin A, and T-2 toxin, are toxic to animals when ingested, inhaled, and when topically applied. Many of the toxins affecting animal production are produced by fungal species from three genera: Fusarium, Aspergillus, and Penicillium. These fungi are ubiquitous and under suitable environmental conditions will grow and produce toxic metabolites in feedstuffs and foods.

Slaframine and Swainsonine Production by Rhizoctonia Leguminicola: Strain Comparsion

The characterization of the mycotoxicosis, “ slobbers” or salivary syndrome in cattle and horses, has led several diverse research groups into interesting and productive areas of inquiry. Slobbers has most frequently been associated with consumption of second-cutting red clover forage infected with the fungus, Rhizoctonia leguminicola. Slobber syndrome has reportedly served to limit the cultivation of red clover in some areas of the midwest (Gough and Elliott, 1956; Aust, 1974). Outbreaks of slobbers are fairly common east of the Mississippi River, and most are associated with red clover hay or forage. Some outbreaks of slobbers have been associated with forage grasses; however, no causal fungus has as yet been isolated (Personal communication, R.J. Cole, USDA/ARS, National Peanut Research Laboratory, Dawson, GA 31742).