Trichothecenes: Natural occurrence and potential hazard

Comparison of the inhibitory effect of T-2 toxin on bovine platelet function with that of other known platelet inhibitors

The inhibitory effects of T-2 toxin on bovine platelet function and thromboxane A(2) production were compared with those of the known inhibitors of human platelet function, acetylsalicylic acid, dipyridamole and verapamil. T-2 toxin (1 × 10(-3)M) effectively inhibited bovine platelet aggregation (33.2-64.3%), whereas neither acetylsalicylic acid nor dipyridamole did so. T-2 toxin appeared to be a less effective inhibitor of platelet aggregation than the calcium channel blocker, verapamil. T-2 toxin (1 × 10(-3)M) added to platelet suspensions together with verapamil, produced an additive inhibitory response. T-2 toxin (2.5 × 10(-4)M) effectively inhibited the release of thromboxane A(2) from ADP-stimulated bovine platelets as did acetylsalicylic acid and verapamil but not dipyridamole. T-2 toxin appears to inhibit bovine platelets by a biochemical mechanism distinct from that of the other inhibitors.

Individual and combined effects of fumonisin B1 present in Fusarium moniliforme culture material and T-2 toxin or deoxynivalenol in broiler chicks

The individual and combined effects of feeding diets containing 300 mg fumonisin B1 (FB1), and 5 mg T-2 toxin (T-2)/kg of diet, or 15 mg/kg deoxynivalenol (DON, vomitoxin) from naturally contaminated wheat were evaluated in two studies in male broiler chicks from day of hatch to 19 or 21 d of age in Experiments 1 and 2, respectively. When compared with controls, body weight gains were reduced 18 to 20% by FB1, 18% by T-2, 2% by DON, 32% by the FB1 and T-2 combination, and 19% by the FB1 and DON combination. The efficiency of feed utilization was adversely affected by FB1 with or without T-2 or DON. Mortality ranged from none for the controls to 15% for the FB1 and T-2 combination. Relative weights of the liver and kidney were significantly increased by FB1 with or without T-2 or DON. Serum concentrations of cholesterol were increased in chicks fed FB1 with or without T-2 or DON. Activities of aspartate aminotransferase, lactate dehydrogenase, and gamma glutamyltransferase were increased in chicks fed FB1 at 300 mg/kg alone and in combination with T-2 or DON, indicating possible tissue damage and leakage of the enzymes into the blood. Results indicate additive toxicity when chicks were fed diets containing 300 mg FB1 and 5 mg T-2/kg of diet and less than additive toxicity when chicks were fed 300 mg FB1 and 15 mg DON/kg of diet. Of importance to the poultry industry is the fact that toxic synergy was not observed for either of these toxin combinations and the likelihood of encountering FB1 at this concentration in finished feed is small. However, under field conditions with additional stress factors, the toxicity of these mycotoxins could be altered to adversely affect the health and performance of poultry.

Effect of polymyxin B nonapeptide and polymyxin B sulphate on trichothecene mycotoxin sensitivity of yeasts using a conductimetric instrument

The addition of polymyxin B sulphate (PBS), or an inactive by-product, polymyxin B nonapeptide (PBN) to a yeast bioassay system, increased its sensitivity to various toxic agents. The nil effect level (NEL) of T-2 toxin was reduced from 0.1 to 0.01 microgram/ml for Kluyveromyces fragilis GK 1005 in the presence of these agents when using a Malthus AT 192 conductimetric instrument. Other synergistic agents (DMSO, ethanol, cetyl trimethyl ammonium bromide and Triton X-100) gave poor results in the conductimetric system. PBN also increased sensitivity of K. fragilis GK 1005 towards cycloheximide in the Malthus system, and PBS reduced the NEL of T-2 toxin for K. fragilis GK 1005 in a disc diffusion assay from 0.2 to 0.04 microgram per disc. No yeasts were found sensitive to the trichothecene deoxynivalenol (DON) even at a DON concentration of 10 micrograms/ml, except in the presence of PBN and PBS. The minimal inhibitory concentration (mic) of DON in the presence of PBS was 2 micrograms/ml for K. fragilis GK 1005.

Preparation of the Fusarium toxin, nivalenol, by oxidation of the putative biosynthetic precursor, 7-deoxynivalenol

Nivalenol is a toxic trichothecene metabolite which is produced by a number of different Fusarium species. However, the nature of its immediate biosynthetic precursor is not known. Oxidation of 7-deoxynivalenol(3 alpha,4 beta,15-trihydroxy-12,13- epoxytrichothec-9-ene-8-one) to nivalenol occurred with reagents known to react by a free radical pathway, such as hydrogen peroxide-ferrous ion-ascorbic acid or lead tetracetate, but not with electrophilic reagents requiring prior formation of the enol. These results suggest that 7-deoxynivalenol or an acetylated derivative could be the biosynthetic precursor of nivalenol.

Response of growing Leghorn chicks to deoxynivalenol-contaminated wheat

Effects of feeding a deoxynivalenol (DON)-contaminated wheat diet containing 18 mg DON/kg were determined in male Leghorn chicks from 1 day to 12 wk of age. The data show that body weights were not adversely affected by the inclusion of the contaminated wheat in the diet. Relative gizzard weights were increased in the chicks receiving the contaminated wheat diet. Consistent significant differences were not observed for relative weights of other organs, serum chemistry, or minerals. A significant decrease in hemoglobin at 4 wk of age occurred, but this effect was transitory in nature; it was no longer present at 8 or 12 wk of age.

Immunosuppressive properties of deoxynivalenol

The immunosuppressive effect of deoxynivalenol (DON) was investigated in male Balb/c mice. The effect of the route of DON administration to the animals was first studied. The results showed that DON acted efficiently on the immune system per os. The administration of 100 ppm DON in the diet caused the death of all the animals within a few days. After oral administration of DON to mice, liver and kidney weights were not changed while the thymus weight was significantly reduced at concentrations greater than 10 ppm. The spleen weight was reduced less than the thymus weight. Histologically, the structure of the thymus was damaged and the high doses produced an atrophy of this organ. Serum levels of anti-sheep red blood cells (SRBC) antibodies were significantly reduced, this effect was dose-dependent. The stimulation of B and T cells by mitogens was depressed: the mitogenic responses were more reduced for thymic cells than for splenic cells. DON inhibited cellular proliferation in vitro, as estimated by [3H]thymidine incorporation:murine splenocytes were more sensitive (IC50 = 131 ng/ml of culture) than XP human fibroblasts (IC50 = 252 ng/ml of culture).

Influence of ochratoxin A and deoxynivalenol on growing broiler chicks

The effects of feeding diets containing ochratoxin A (OA) (2.0 mg/kg) and deoxynivalenol (DON) (16 mg/kg) singly and in combination were characterized in male broiler chicks from 1 to 3 wk of age. Body weight gains and efficiency of feed utilization were significantly reduced by feeding OA singly, DON singly, and the OA/DON combination. Increased relative liver, kidney, and proventriculus weights were observed in the OA and OA-DON groups and blood urea nitrogen (BUN) was increased in the DON group. Serum uric acid, creatinine, and triglycerides were significantly elevated, and total protein, albumin, cholesterol, and aspartate amino transferase (AST) activity were decreased in the OA group. Histopathological examination of the liver, kidney, spleen, proventriculus, gizzard, and bursa revealed that lesions were confined primarily to mild hepatocellular degeneration, with milk diffuse lipidosis of the liver and mild swelling of the renal tubular epithelium of the OA and OA/DON combination groups. For a few parameters such as efficiency of utilization and relative liver, gizzard, and spleen weights. OA and DON appear to interact additively. However, many of the parameters such as body weights, body weight gains, BUN, total protein, and AST show significant interactions that can best be described as less than additive or in some cases antagonistic.

Effects of feeding deoxynivalenol (DON, vomitoxin)-contaminated wheat to female White Leghorn chickens from day old through egg production

White Leghorn chickens one day of age were fed starter and grower diets containing either a control (noncontaminated) wheat diet or a naturally contaminated deoxynivalenol (DON) wheat diet (18 mg DON/kg) from 1 day of age to the onset of egg production. The hens were then placed on their respective layer diets of control wheat or DON-contaminated wheat (18 mg DON/kg) for six 28-day egg production periods. Feeding the DON-contaminated diet did not significantly influence body weights during the growing or the laying phases. Overall, hen-day egg production and egg weights were significantly higher for hens receiving the DON diet. Feeding DON contaminated wheat caused no significant changes in percent shell, albumen height, percent fertility, percent hatch of fertile eggs, percent hatch of eggs set, or weight of chicks at hatch. There were slight, although significant, changes in shell weight and shell thickness and in some serum chemistry values. There were no significant differences in the hematology parameters measured or in prothrombin times. None of the eggs collected from hens fed the control and the DON-contaminated wheat diet contained detectable quantities of DON. Microscopic examination of sections of the liver, kidney, and proventriculus of control and treated hens revealed no unusual histopathology. The results indicate that feeding DON at relatively high levels beginning at 1 day of age and continuing through six egg production periods had only slight effects on the parameters measured.

Developmental toxicity of diacetoxyscirpenol in the mouse

Mycotoxins (frequently referred to as secondary metabolites of toxigenic fungi) are commonly found in foodstuffs and are important because of their association with disease. The mycotoxin diacetoxyscirpenol, or 3-hydroxy-4,15-diacetoxy-12,13-epoxytrichothec-9-ene (DAS), is produced by numerous species of Fusarium and is reportedly toxic to humans and animals. The teratogenic potential of DAS was determined in time-mated ICR mice. DAS (dissolved in a 1:9 mixture of propylene glycol/saline) was administered intraperitoneally to pregnant mice at levels of 1.0, 1.5, 2.0, 3.0 and 6.0 mg/kg body weight in a single dose on one of gestation days 7-11 during the period of organogenesis. Term fetuses were examined for anomalies by routine teratologic procedures. Reabsorption frequency was dose-related and occurred as follows: 100% at 6.0 mg/kg on all gestation days tested; 90-99% at 3.0 mg/kg on days 7-9 and 100% on days 10 and 11; 26-51% at 2.0 mg/kg on days 7-9 and 100% on days 10 and 11; 9-77% at 1.5 mg/kg on days 7-10 and 100% on day 11; 7-34% at 1.0 mg/kg on days 7-11. A significant reduction in mean fetal body weight and a variety of fetal malformations (i.e. external and skeletal) were observed following maternal exposure to DAS. This is the first report to implicate this mycotoxin as a teratogen.

Impact of high dietary vomitoxin on yolk yield and embryonic mortality

Single Comb White Leghorn hens at 58 weeks of age were given control (C) and vomitoxin (V)-contaminated feed for 4 weeks; then the V treatment was changed to C for 2 subsequent weeks. Fusarium graminearum-infected corn was substituted for sound corn to attain a practical extreme of 38 ppm V. Hen-day production, feed consumption, body weight, and gross pathology were the same between treatments. Egg weight, internal quality, and shell strength were not adversely affected; however, dietary V led to a small reduction in the percentage of yolk while albumen increased. Solids content of both egg components remained unchanged, and no V as such could be detected (less than .2 ppm). Presence of toxic V metabolites in the egg were indicated by increased (although still low) embryonic mortality upon incubation. Improvement in yolk yield and relief from germ losses occurred 1 week after the change from V to C feed. Overall responses to present extreme circumstances were no greater than variation occurring between weeks, and problems in practice seem remote.

Effects of feeding mature White Leghorn hens diets that contain deoxynivalenol (vomitoxin)

Mature White Leghorn hens that had been fed a commercial laying diet were changed to a wheat-based diet over a period of 42 days. Two groups were formed based on equivalent egg production and body weights and randomly assigned to either a control (noncontaminated) wheat diet or a naturally contaminated deoxynivalenol (DON, vomitoxin) wheat diet (18 mg DON/kg). Hens were provided their respective diets and water ad libitum for 112 days along with 16 hr of light. The DON-contaminated diet did not significantly influence hen body weights, hen day egg production, egg weights, or efficiency of feed utilization. Internal egg quality, as measured by albumin height, was slightly, although significantly, improved by feeding the DON-contaminated wheat diet. Egg shell weight and percent egg shell were slightly, although significantly, decreased by feeding the DON-contaminated diet, whereas shell thickness was not altered. No deleterious effects were observed in fertility, hatchability, or chick weights at hatch. The results indicate that laying hens are affected only slightly when fed naturally contaminated wheat diets containing approximately 18 mg DON/kg for 112 days.

Rapid screening procedure for the detection of trichothecenes in plasma and urine

A rapid and easy procedure to screen for trichothecenes in plasma and urine is presented. The toxins are extracted using a Clin-Elut column, hydrolyzed to their corresponding parent alcohols and cleaned up with a silica cartridge followed by derivatization for gas chromatographic analysis. The detection of any of the parent alcohols in plasma or urine would indicate an exposure to trichothecenes. Recoveries in urine are between 78 and 119% at levels of 50-1000 ng/ml and recoveries in plasma are between 80 and 116% at levels of 50-500 ng/ml. The limit of detection is better than 25 ppb.

Effects of feeding hens a high level of vomitoxin-contaminated corn on performance and tissue residues

A balance experiment was conducted with hens fed a high level of vomitoxin (V) to study the effect on live performance, egg quality, and tissue residues of V. Twenty Single Comb White Leghorn (SCWL) hens, approximately 26 weeks of age, were individually housed in metabolic cages and fed a control (C) or V (82.8 mg/kg) diet for 27 days. No significant differences were observed in feed consumption, body weight gain, egg production, egg weight, haugh units, shell deformation, or egg shell thickness between treatments. No gross pathological lesions were observed in the oral cavity, proventriculus, small or large intestine, liver, spleen, heart, or kidney. Small erosions were present in the gizzard mucosa of birds fed the V-diet. No significant V residues were found in the yolk, albumen, egg shell, liver, kidney, thigh, or breast muscle, but levels of approximately 20 ppb were found in the gizzard. About 4.2% of the total V consumed by hens were recovered in the feces.

Induction of chromosome aberrations by fusarium T-2 toxin in cultured human peripheral blood lymphocytes and Chinese hamster fibroblasts

T-2 toxin is an important representative of trichothecenes produced by various species of imperfect fungi, mainly Fusarium genus. It is a naturally occurring toxin that can cause severe diseases in human and animals. No definite data demonstrating the carcinogenic potential of T-2 toxin had been reported up to now. We demonstrated that T-2 toxin reproducibly induced chromosomal structural aberrations both in cultured human peripheral blood lymphocytes as well as in V79 Chinese hamster fibroblasts. The mean percentage of cells with aberration of human lymphocytes from normal individuals induced by T-2 toxin is 49-fold (9.8%) of the mean percentage of corresponding control cultures without T-2 toxin (0.2%). T-2 toxin induced chromosome type (76%) as well as chromatid type (24%) of aberrations; among them, acentric fragment (46%) was the most common type, and chromatid gap, deletion, and chromosome gap were the next most common. T-2 toxin can induce aberrations in cells at different phases of the cell cycle. There are definite dose-effect relationships within a certain range of dosage of T-2 toxin in experiments with both human peripheral blood lymphocytes and V79 cells. T-2 toxin exhibited three types of effects on cells, namely, mitogenic at lowest concentration, clastogenic (chromosome aberration) at median concentration, and cytotoxic at higher concentration. The dose-effect curves of these three effects are partly overlapping. There is some interindividual difference in sensitivity of response for the clastogenic effect of T-2 toxin, but no resistant individual was observed. Sex or age effect was not observed. The above results suggest that T-2 toxin has carcinogenic potentials. The dosage of aflatoxin that can induce chromosomal aberration of human peripheral blood lymphocytes is thousands-fold of the dosage of T-2 toxin as shown in this report. T-2 toxin might have more hazardous potentials than had been previously considered. The carcinogenic potential of T-2 toxin and related trichothecenes and their possible roles in carcinogenesis of upper gastrointestinal (G.I.) tract cancers need to be further investigated.

The tolerance of White Leghorn and broiler chicks, and turkey poults to diets that contained deoxynivalenol (vomitoxin)-contaminated wheat

Three experiments were done to determine the effects of giving White Leghorn chickens, broiler chickens, and turkey poults diets that contained white winter or spring wheat contaminated with 4-deoxynivalenol (DON). Diets that contained .35 and .7 mg DON/kg from winter wheat did not (P greater than .05) influence feed intake, body weight gain, feed/gain ratio, and organ weight/body weight ratios of Leghorn and broiler chickens, and poults when fed between 7 and 21 days in Experiment 1. Dietary DON levels up to 4.6 mg/kg increased the feed intakes (P less than .01) and daily body weight gains (P less than .05) of Leghorn chickens between 7 and 35 days of age in Experiment 2 but had little effect (P greater than .05) on these variables for broiler chickens between 7 and 52 days of age in Experiment 3. Within Experiments 2 and 3, feed/gain ratios and organ weight/body weight ratios were similar among the Leghorn and broiler chickens, respectively. The dressing percent and chilled carcass weights of eviscerated broiler chickens were not affected (P greater than .05) by DON in the diets of Experiment 3. Mortality was low (less than 3.3%) for the three experiments and necropsy examination indicated that the birds died from several causes unrelated to the dietary treatment. There was no evidence of emesis during the experiments or of overt changes in the appearance of the oral cavity, heart, liver, spleen, kidney, proventriculus, gizzard, and intestines of a random sample of birds killed by carbon dioxide asphyxiation and necropsied. Differences occurred between the analyzed and calculated DON contents of the experimental diets; possible reasons for these differences are discussed. The results of these experiments indicate that young chickens and turkey poults can tolerate diets that contain DON up to at least 5 mg/kg from white winter or spring wheat.

Toxic fungal metabolites in food

About 100 fungal metabolites may cause cancer, embryological defects, or other histopathological effects in mammals. They are produced by a wide variety of fungi. Few of these metabolites have significant acute toxicity. With the exception of aflatoxin B1 and sterigmatocystin, there is no conclusive evidence that any of them is carcinogenic. However, several of the compounds are mutagenic. Cytochalasin D and T-2 toxin are probably teratogenic. A wide variety of other histopathological effects have been shown. Liver damage has been most frequently reported. In almost all cases the molecular bases of these effects have not been extensively investigated. Although much is known about the routes by which some of the compounds are synthesized in vivo, nothing is known about control at the molecular level of these biosynthetic routes. Little is known about the biological degradation of these compounds or about the levels and incidences of them in food and animal feed. Future work in all these areas will depend on the further development of sensitive assay methods that are applicable to their measurement in food, in animal feed, and in animal tissues and body fluids and on the application of these methods to define exposure to these compounds in the diet.

Mycotoxins produced from fungi isolated from foodstuffs and soil: comparison of toxicity in fibroblasts and rat feeding tests

Thirty-nine isolates of fungi obtained from foodstuffs and soil samples from various parts of the world have been identified. The isolates were grown on a solid rice medium, and extracts were prepared with 50% aqueous methanol. The extracts were examined for toxicity in the following systems: (i) cytotoxicity to cultured normal human diploid skin fibroblasts (proliferating and nonproliferating) and mouse fibroblasts; (ii) skin toxicity after topical application on rats; and (iii) rat feeding tests in which rats were examined for death, overt pathological effects including congestion and hemorrhage of tissues, weight loss, food refusal, and uterine growth. Sixteen culture extracts were highly toxic as indicated by death, congestion and hemorrhage of tissues, and net weight loss. One half of the isolates were highly cytotoxic (50% lethal concentration, 0.01 to 5 micrograms/ml) as indicated by the ability to cause death and disintegration of 3T3 Swiss mouse fibroblasts and human diploid skin fibroblasts during 3 to 4 days in culture. The remainder were moderately cytotoxic (50% lethal concentration, 5 to 250 micrograms/ml). Four culture extracts were highly toxic by some clinical criteria but did not cause congestion and hemorrhage of tissues and were weakly cytotoxic (50% lethal concentration, 250 to 5,000 micrograms/ml). Six culture extracts exhibited moderate toxicity (weight loss only) and low cytotoxicity (50% lethal concentration, 3,000 to 50,000 micrograms/ml). Four culture extracts caused uterine enlargement as the major clinical sign, suggesting the presence of zearalenone. Eleven culture extracts were weakly cytotoxic and caused no major clinical signs, except skin toxicity in two extracts.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunoperoxidase localization of T-2 toxin

Antibody against T-2 toxin was used for monitoring the fate of T-2 toxin in mice given a single po dose of 11 mg/kg by the peroxidase-antiperoxidase (PAP) method. T-2 toxin was demonstrable in the esophagus from 5 min to about 24 hr postdosing. In the stomach, T-2 toxin was detected within the cytoplasm of intact and injured epithelial cells. In the duodenum, T-2 toxin was primarily localized within the surface epithelium and phagocytic elements (macrophages and neutrophils) of the duodenal lamina propria, especially toward the tips of the villi. Following sloughing of duodenal villous tips, the recovering villous tip epithelial cells frequently showed both cytoplasmic and nuclear T-2 toxin. The jejunum showed weak T-2 toxin within the cytoplasm of villous tip epithelial cells only. The ileum never demonstrated T-2 toxin. Tissue response in the gastrointestinal (GI) tract was characterized by transient edema, marked cytolysis and sloughing, and a subsequent leukocytic invasion of the stomach and proximal small intestine. Evidence of severe gastric and less severe duodenal bleeding was apparent and associated with a marked loss of gastric epithelium and intestinal villous tips. The kidney medulla contained the majority of T-2 toxin stain. T-2 toxin was noted within the distal tubular cells, the cells of the collecting tubules, and the epithelium covering the papilla. T-2 toxin was never demonstrated in any of the hepatic tissue examined.

Trichothecene-induced hemolysis. I. The hemolytic activity of T-2 toxin

In the present investigation, the hemolytic properties of T-2 toxin were examined. Tests with different concentrations of T-2 toxin showed that essentially complete hemolysis of rat erythrocytes commenced after a lag period, the length of which depended on the concentration of toxin. Comparison of the characteristics of hemolysis caused by T-2 toxin, saponins, H2O2, and polyoxyethylene surfactants showed great similarity between T-2 toxin and the latter two which proceed by a free radical mechanism. The same mechanism was suggested for hemolysis caused by T-2 toxin on the basis of the additional following observations: (1) darkness inhibited hemolysis; (2) specific free radical scavengers, i.e., vitamin E, mannitol, and histidine, inhibited hemolysis caused by T-2 toxin.

Enzyme-linked immunosorbent assay for detection of T-2 toxin

A microtest plate enzyme immunoassay has been developed for the detection of T-2 toxin. Haptenic T-2 hemisuccinate was immobilized on polystyrene surfaces coated with poly(D-lysine). rabbit antisera against T-2 toxin were added. The binding of the first antibody was detected by addition of an anti-rabbit-immunoglobulin/peroxidase conjugate. After conversion of the substrate 2,2'-azinobis(3-ethyl-2,3-dihydrobenzothiazole-6-sulfonate)/H2O2, the absorbance at 414 nm was monitored. Presence of free T-2 toxin during the first incubation step led to a concentration-dependent lowering of absorbance. The lower detection limit was at about 2 pg per assay. The cross reactivity of T-2 toxin antiserum with other trichothecenes, as determined by ELISA, is weaker than that reported by other authors using a radio-immunoassay technique.

High tolerance of broilers to vomitoxin from corn infected with Fusarium graminearum

Corn purposely infected with Fusarium graminearum was found to contain 800 to 900 mg vomitoxin/kg. Contaminated corn was substituted for control corn at 0, 6, 12, 18, and 24% in a corn-soybean meal ration. Broiler cockerels were given each experimental diet from 6 to 11 days of age; then sample groups were necropsied. Remaining birds were subsequently offered commercial starter for 2 days and sample groups again necropsied. Growth and diet consumption were not significantly reduced until contaminated corn exceeded 12% of the ration (116 mg vomitoxin/kg). Alertness, coordination, and feathering appeared normal regardless of treatment. Birds that received contaminated corn exhibited plaques in the mouth and gizzard erosions proportional to the level of substitution. All lesions were generally restricted to the epithelial layer and no liver or kidney involvement could be demonstrated. A short return to uncontaminated feed eliminated most lesions. Fowl appear to be considerably more tolerant of vomitoxin than swine.

Effects of feeding vomitoxin contaminated wheat on the performance of broiler chickens

Two experiments were conducted to ascertain the effect of feeding vomitoxin to meat-type chickens. In each experiment 360 day-old commercial chickens of the Shaver strain were housed in Petersime batteries for 28 days and fed diets containing 0, 12, 24, 36, 48, and 60% of wheat containing 3.00 ppm of vomitoxin. Analysis indicated that the vomitoxin levels in the diets ranged from less than .02 (control) to 1.87 ppm. Each diet was fed in either the all-mash or the crumbled form. There was no evidence of feed refusal or emesis nor were there any significant effects on mortality, body weight gain, live body weight, feed consumption, or feed conversion when these diets were fed. Subjecting the feeds to the pelleting crumbling process had no effect on the level of vomitoxin found in the finished feed. No organ damage from feeding vomitoxin was evident.