Individual and combined toxicity of T-2 toxin and cyclopiazonic acid in broiler chicks

Cyclopiazonic acid: 50th anniversary of its discovery

In 1968, the mycotoxin cyclopiazonic acid (CPA) was first discovered and characterised as a chemical substance. Within the following five decades, much has been learned from the results of CPA research. CPA is produced by several Penicillium species (P. griseofulvum, P. camemberti, P. commune, P. dipodomyicola) and Aspergillus species (A. flavus, A. oryzae and A. tamarii). It is widespread on naturally contaminated agricultural raw materials. CPA has been reported to occur in food commodities (e.g. oilseeds, nuts, cereals, dried figs, milk, cheese and meat products) and to possess toxicological significance. CPA is also frequently detected in peanuts and maize; the presence of CPA and aflatoxins in maize and peanuts contaminated with A. flavus suggests that synergism may occur. CPA is toxic to several animal species, such as rats, pigs, guinea pigs, poultry and dogs. After ingesting CPA-contaminated feeds, test animals display severe gastrointestinal upsets and neurological disorders. Organs affected include the liver, kidney, heart, and digestive tract, which show degenerative changes and necrosis. Biologically, CPA is a specific inhibitor of sarco(endo)plasmic reticulum Ca2+-ATPase. Data from toxicological evaluation of aflatoxins and CPA in broiler chickens demonstrate that both aflatoxins and CPA alone and the aflatoxin-CPA combination can adversely affect broiler health. The effects of aflatoxins and CPA combination were additive in most cases.

Revisión: Implicaciones toxicológicas y nutricionales de la toxina T-2 / Review: Toxicological and nutritional implications of T-2 toxin

Trichothecenes are mycotoxins produced by species of the genus Fusarium. These toxins are associated with health problems in humans and animals. The most common trichothecenes in cereals are deoxynivalenol, HT-2 toxin, diacetoxyscirpenol, nivalenol, neosolaniol and T-2 toxin; the latter is the most widely studied because it is easy to produce in the laboratory. The effects of T-2 toxicosis include dermatonecrosis, reduced body weight and efficiency of food utilization, severe diarrhoea, haemorrhage, necrosis of the upper alimentary tract, anaemia, immuno suppression ; and in birds, poor feathering. This paper reviews the latest information about the occurrence, chemical characteristics, toxicity, metabolic alterations, biotransformation and detoxifi cation methods of the T-2 toxin.

Review Article: Safety Assessment of the Mycotoxin Cyclopiazonic Acid

Cyclopiazonic acid (CPA) is an indol-tetramic acid mycotoxin and is produced by the nearly ubiquitous molds, Aspergillus and Penicillium. CPA produced by these molds has been identified in a number of food sources (including, but not limited to, grain, legumes, meat, milk, and cheese) and from parasitic infections of man and other animals. Few incidents of CPA mycotoxicoses have been reported because of the benign nature of the intoxication, the small amounts present, and its effects may be disguised with concurrent aflatoxicosis (some toxicity data may have been generated using aflatoxin-contaminated CPA). CPA is absorbed in the gastrointestinal tract and following oral administration; it has a half-life of approximately 30 hours and is excreted largely unchanged in the urine and feces. Cyclopiazonic acid is not considered to be a potent acute toxin as its oral LD50 in rodents is in the range of 30 to 70 mg/kg. Multiple dose studies also show a range of effects in several species and among mammalian models, the pig appears to be the most sensitive with a no-observable-effect level (NOEL) in the range of 1.0 mg/kg/day. The preponderance of evidence from the rat and other test animals supports this dose as a defensible estimate of a no effect level. The target organs of CPA toxicity appear to be muscle, hepatic tissue, and spleen, with a localization in the former, although a more apparent toxic change in the latter two. The toxicity and symptoms of CPA poisoning can be attributed to its ability to alter normal intracellular calcium flux through its inhibition of the reticular form of the Ca2+-ATPase pump. CPA was not teratogenic in mice. CPA is not considered a carcinogen and the weight of evidence militates against its characterization as a mutagen. Despite CPA-induced pathological changes ascribed to the spleen or bursa of Fabricius, there does not appear to be an effect on the immune system. In vitro studies imply a potential immunomodulatory effect of CPA, but in all of those reports very high concentrations of CPA were required and none of these findings have been supported with in vivo studies. Therefore, based on a NOEL of 1 mg/kg/day and accounting for species variation, an appropriate acceptable daily intake (ADI) would be approximately 10 μg/kg/day or 700 μg/day. In the context of human exposure, if the uppermost limit of CPA found in cheese is 4 μg/g and the average individual consumes 50 g of cheese daily, this allows an intake of 200 μg, less than one third of a traditionally established ADI.

Experimental pathology of T-2 toxicosis and mycoplasma infection on performance and hepatic functions of broiler chickens

This experiment was conducted using 192 day-old Ross 308 chicks, divided into 4 groups of 4 replicate consisting 48 birds. Group I was fed a control diet, Group II was fed control diet supplemented with 0.5 ppm T-2 toxin for 5 weeks, Group III was fed control diet supplemented with 8 × 10(8) cfu/mL of Mycoplasma gallisepticum, and group IV was fed control diet supplemented by T-2 toxin and Mycoplasma gallisepticum. Body weight and feed conversation ratio (FCR), relative organ weights, clinical signs, biochemical characteristics, and gross and histopathological lesions were recorded in the experimental groups at the end of the second and fifth weeks of age. Body weight and relative weights of bursa of Fabricius, thymus, and spleen decreased and FCR increased significantly (P ≤ 0.05), but the relative weights of liver and kidney showed no significant decrease (P ≤ 0.05) in the serum total proteins, albumin, and increase in aspartate aminotransferase and alanine transaminase were observed in T-2 toxin and T-2 accompanied with Mycoplasma fed birds when compared to the control group. Liver was enlarged, friable, and yellowish discoloration with distended gall bladder was noticed. Lymphoid organs such as bursa of Fabricius, thymus, and spleen were atrophied in group II and group IV throughout the study. Microscopically, liver showed vacuolar degeneration of hepatocytes, with increased Kupffer cell activity, bile duct epithelial hyperplasia, and infiltration of inflammatory cells. Kidney showed vacuolar degeneration of tubular epithelium along with pyknotic nuclei. Lymphoid organs showed lymphocytolysis and depletion with prominent reticuloepithelial cells. Proventriculus revealed desquamation of villous epithelial cells and lymphoid infiltration in submucosa. Heart showed mild hemorrhage with infiltration of inflammatory cells. Lung showed edema and inflammatory cells in the bronchioles. Trachea showed desquamation and erosions of mucosa. Proliferation of mucosal glands with increased mucous secretion was obvious. Air sacs showed thickening with presence of inflammatory cells and edema.

Mycotoxin co-contamination of food and feed: meta-analysis of publications describing toxicological interactions

Most fungi are able to produce several mycotoxins simultaneously; moreover food and feed can be contaminated by several fungi species at the same time. Thus, humans and animals are generally not exposed to one mycotoxin but to several toxins at the same time. Most of the studies concerning the toxicological effect of mycotoxins have been carried out taking into account only one mycotoxin. In the present review, we analysed 112 reports where laboratory or farm animals were exposed to a combination of mycotoxins, and we determined for each parameter measured the type of interaction that was observed. Most of the published papers concern interactions with aflatoxins and other mycotoxins, especially fumonisins, ochratoxin A and trichothecenes. A few papers also investigated the interaction between ochratoxin A and citrinin, or between different toxins from Fusarium species. Only experiments with a 2×2 factorial design with individual and combined effects of the mycotoxins were selected. Based on the raw published data, we classified the interactions in four different categories: synergistic, additive, less than additive or antagonistic effects. This review highlights the complexity of mycotoxins interactions which varies according to the animal species, the dose of toxins, the length of exposure, but also the parameters measured.

An industry perspective on the use of "atoxigenic" strains of Aspergillus flavus as biological control agents and the significance of cyclopiazonic acid

Several nonaflatoxigenic strains of Aspergillus flavus have been registered in the United States to reduce aflatoxin accumulation in maize and other crops, but there may be unintended negative consequences if these strains produce cyclopiazonic acid (CPA). AF36, a nonaflatoxigenic, CPA-producing strain has been shown to produce CPA in treated maize and peanuts. Alternative strains, including Afla-Guard® brand biocontrol agent and K49, do not produce CPA and can reduce both aflatoxin and CPA in treated crops. Chronic toxicity of CPA has not been studied, and recent animal studies show significant harmful effects from short-term exposure to CPA at low doses. Grower and industry confidence in this approach must be preserved through transparency.

Cyclopiazonic acid biosynthesis of Aspergillus flavus and Aspergillus oryzae

Cyclopiazonic acid (CPA) is an indole-tetramic acid neurotoxin produced by some of the same strains of A. flavus that produce aflatoxins and by some Aspergillus oryzae strains. Despite its discovery 40 years ago, few reviews of its toxicity and biosynthesis have been reported. This review examines what is currently known about the toxicity of CPA to animals and humans, both by itself or in combination with other mycotoxins. The review also discusses CPA biosynthesis and the genetic diversity of CPA production in A. flavus/oryzae populations.

Dose-dependent effects of T-2 toxin on performance, lipid peroxidation, and genotoxicity in broiler chickens

The objective of the present study was to evaluate the effects of different concentrations of T-2 toxin in feed on performance, lipid peroxidation, and genotoxicity in vivo. For a 17-d period, T-2 toxin was added to the diet of the chickens. Fifty 22-d-old male broiler chickens were divided into 5 groups that were supplemented with different concentrations of T-2 toxin: control (0.0 mg/kg of feed), T 0.5 (0.5 mg/kg of feed), T 1.5 (1.5 mg/kg of feed), T 4.5 (4.5 mg/kg of feed), and T 13.5 (13.5 mg/kg of feed). Deoxyribonucleic acid fragmentation in spleen leukocytes, malondialdehyde in plasma and liver, total plasma antioxidative status, glutathione peroxidase activity, and total serum Ig (IgA and IgG) were measured. Feed consumption and BW gain decreased when the concentration of T-2 toxin was 4.5 and 13.5 mg/kg of feed. Compared with the control group, the rate of DNA damage increased significantly in the group fed 13.5 mg of T-2 toxin/kg of feed. In contrast to DNA fragmentation, indicators of oxidative stress did not show differences between groups fed T-2 toxin and the control. More serum IgA was detected in the group T 13.5 compared with the control, whereas there were no differences in serum IgG levels. The results of the present study indicate that impaired performance, DNA fragmentation in spleen leukocytes, and elevated serum IgA levels induced by T-2 toxin are dose-dependent. Based on our results, we could not confirm the hypothesis that oxidative stress is among the mechanisms by which T-2 toxin induces DNA fragmentation.

The role of dietary nucleotides in reduction of DNA damage induced by T-2 toxin and deoxynivalenol in chicken leukocytes

The objective of present study was to determine the effect of T-2 toxin and deoxynivalenol (DON) on DNA fragmentation in spleen leukocytes and oxidative stress in chickens, and furthermore, to evaluate the potential of dietary nucleotides in reduction of toxin-induced DNA damage. Male broiler chickens were exposed to 10mg/kg feed of either T-2 toxin or DON with or without addition of dietary nucleotides. After 17 days of treatment DNA damage of spleen leukocytes was measured by Comet assay, lipid peroxidation was studied by malondialdehyde (MDA), total antioxidant status (TAS) of plasma and glutathione peroxidase (GPx) assays, and the hepatotoxicity was studied by measuring plasma liver enzyme levels (ALT, AST and GGT) levels. T-2 toxin and DON induced DNA fragmentation in chicken spleen leukocytes and supplementation with nucleotides reduced the amount of damage only when added to T-2 toxin. In comparison to control group, values of TAS and AST decreased significantly in the groups fed T-2 toxin with or without nucleotide supplementation. Plasma and liver MDA content in groups fed T-2 toxin and DON did not differ significantly from the control. Dietary nucleotides did not affect MDA formation when added to the diets with mycotoxins. The results obtained suggest that dietary nucleotides have the potency to reduce the extent of DNA damage induced by the action of T-2 toxin in immune cells. This underlines their possible beneficial effect on the immune system in mycotoxin intoxication.

Efficacy of sodium bentonite as a detoxifier of broiler feed contaminated with aflatoxin and fumonisin

Sodium bentonite (SB) was evaluated for its ability to reduce the deleterious effects of fumonisin B1 (FB1) and aflatoxin B1 (AFB1) in broiler diets. It was incorporated into the diets (0.3%) containing 2.5 mg/kg AFB1, 200 mg/kg FB1, or a combination of 2.5 mg/kg AFB1 and 200 mg/kg FB1. Aflatoxin B1 significantly diminished body weight gain, whereas FB1 or the combination of FB1 and SB had no effect. Addition of SB in the diets significantly diminished the inhibitory effects of dietary AFB1. Feeding AFB1 alone caused significant increases in the relative weights of most observed organs. Feeding FB1 alone did not alter relative weights of any organs. In the combined diet (AFB1 plus FB1) relative weights of the liver, kidney, gizzard, and spleen were increased. Addition of SB to the diet containing AFB1 diminished the relative weights of liver, kidney, and spleen. Addition of SB to diets containing AFB1 and FB1 only decreased liver weights. In relation to the control, lower serum levels of total protein, albumin, and globulins were observed for all AFB, containing diets without SB addition, whereas all other treatments were not altered. Livers of birds fed diets containing AFB1 and a combination of AFB1 and FB1 were enlarged, yellowish, friable, and had rounded borders. The histopathology of them, stained with hematoxylin and eosin, showed multifocal and varied cytoplasmatic vacuolization with perilobular location. Incorporation of SB reduced the incidence and severity of the hepatic histopathology changes associated with aflatoxicosis.

Influence of dietary culture material containing aflatoxin and T2 toxin on certain serum biochemical constituents in Japanese quail

Forty newly hatched unsexed Japanese quail (Coturnix coturnix japonica) chicks were fed diets containing 3 ppm aflatoxin (AF) and 4 ppm T(2) toxin either singly and in combination for 35 days. Sera samples were collected from six birds in each group at the end of the trial to study the effect of certain serum biochemical parameters. Highly significant (P < 0.01) differences were observed for serum total protein, albumin, globulin, glucose, cholesterol, aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP) and gamma glutamyl transferase (GGT) between control and toxin treated groups. Toxin treated groups did not reveal any significant difference for serum urea nitrogen, creatinine, uric acid, calcium, phosphorus, sodium and potassium. There was a reduction in the levels of serum total protein, albumin, globulin, glucose, cholesterol, ALT and elevation of AST and GGT and variable ALP levels observed in toxin treated groups.

Cecal volatile fatty acids and broiler chick susceptibility to Salmonella typhimurium colonization as affected by aflatoxins and T-2 toxin

Four experiments were conducted using day-of-hatch, mixed-sex broiler chicks to evaluate the effects of aflatoxins and T-2 toxin on cecal volatile fatty acids (VFA) and the susceptibility to Salmonella colonization. All chicks in these experiments were challenged orally with 10(4) cfu of Salmonella typhimurium (ST) on Day 3. In Experiments 1 and 2, chicks were fed diets containing 0, 2.5, or 7.5 mg aflatoxins/kg of diet and were allowed to develop their microflora naturally. In Experiment 3, all chicks were orally gavaged on the day of hatch with a competitive exclusion (CE) culture (PREEMPT) and were fed diets containing 0, 2.5, or 7.5 mg T-2 toxin/kg. In Experiment 4, the chicks were fed diets containing 0, 7.5, or 15.0 mg T-2 toxin/kg and one-half of the chicks were orally gavaged on the day of hatch with the CE culture. In Experiments 1 and 2, with the exception of increased total VFA at 5 d in chicks fed the 7.5 mg T-2 aflatoxins/kg diet, there were no treatment effects on cecal propionic acid, total VFA, or incidence or severity of ST colonization. In Experiment 3, the only alteration in concentration of cecal propionic acid or total VFA was a significant reduction in total VFA at 5 d in chicks fed the 2.5 mg T-2 toxin/kg diet. No significant treatment differences were observed for numbers of Salmonella cecal culture-positive chicks or for numbers of ST in the cecal contents. In Experiment 4, with minor exceptions, the chicks treated with the CE culture had higher cecal concentrations of propionic acid and were less susceptible to Salmonella colonization than the non-CE-treated chicks. In the non-CE-treated chicks, T-2 toxin had no effect on any of the parameters, and 85 to 90% of the chicks were Salmonella cecal culture-positive. In the CE-treated chicks, there was a decrease in propionic acid concentration at 3 and 11 d and an increase in susceptibility to Salmonella colonization of the chicks fed the 15.0 mg T-2 toxin/kg diet. These results indicate that cecal concentrations of VFA can be affected by toxins, such as high concentrations of T-2 toxin, and that resistance to Salmonella colonization may be reduced. Further research is necessary to determine the biological significance of these changes.

Mycotoxins, fungus and 'electrohypersensitivity'

'Electrohypersensitivity' is often explained as a psychological syndrome. Our modern environment contains a lot of different substances and some of them are toxic. Mycotoxins are types of toxins that are biologically very active and that affect living organisms. Mycotoxins and fungi capable of producing toxins have been detected in ventilation systems, water damage and in foodstuff. Many of those displaying symptoms caused by electromagnetic fields have fungus infections or have been living in fungus-contaminated environments for long periods. In animal studies mycotoxins have shown the same effects as those seen in the 'electrohypersensitivity' syndrome. Phototoxic reactions are well known in veterinary medicine and in medical science, so the question is whether the 'electrohypersensitivity' syndrome is caused by 'phototoxic' reactions?

Effects of feeding aFusarium poae extract and a natural zeolite to broiler chickens

A feeding trial was conducted in order to determine the effects of aFusarium poae extract on the health and performances of broiler chickens and the possible protective effect of a natural zeolite. TheF. poae extract contained nivalenol, T-2 toxin and diacetoxyscirpenol and demonstrated high toxicity when administeredi.p. to rats. One-day-old broiler chickens were fedad libitum over a period of 28 days with the following diets: group I - control; group II - 0.5% zeolite; group III -F. poae extract; group IV-0.5% zeolite andF. poae extract. Broilers were sacrificed at 28 days for the measurement of relative organs weights, leukocyte counts and serum biochemical values. No mortality was recorded over the experiment. Body weight gains, feed intake, feed utilisation and water consumption were depressed by theF. poae extract (p<0.05). A decrease of these parameters were also observed in group IV which received the diet with zeolite and theF. poae extract. No significant differences were seen in group II when compared to control. In groups III and IV the relative weights of liver, kidney, hearth and gizzard were significantly increased (p<0.05), while in group II only the relative liver weight was increased.F. poae extract, administered singly or in combination with zeolite, significantly decreased leukocytes count, serum total protein and serum albumin. Zeolite andF. poae extract, singly or combined, increased serum creatinine and uric acid concentrations (p<0.05).These findings indicate that sublethal doses of F. poae extract can affect adversely the performances and the health in broiler chickens. By adding zeolite these impairments could not diminished and for some parameters the zeolite additive increased the adverse effects of the F. poae extract.

Toxicological evaluations of cyclopiazonic acid and ochratoxin A in broilers

The individual and combined effects of ochratoxin A (OA) and cyclopiazonic acid (CPA) were evaluated in Petersen x Hubbard broiler chickens from 1 d to 3 wk of age. The experimental design was a 2 x 2 factorial with treatments of 0 and 2.5 mg OA/kg feed and 0 and 34 mg CPA/kg feed. Production performance, serum biochemistry, and gross pathological observations were evaluated. Body weight gain was reduced (P < 0.05) by OA, CPA, and OA-CPA in combination at the end of 3 wk. Ochratoxin A significantly increased the relative weight of the kidney and serum concentrations of uric acid and triglycerides and decreased total protein, albumin, and cholesterol. The toxicity of CPA was expressed primarily through increased relative weights of the proventriculus and increased activity of creatine kinase. Exposure to OA-CPA was characterized by increased relative weights of the liver, kidney, pancreas, and proventriculus; decreased concentrations of serum albumin, total protein, and cholesterol; increased activity of creatine kinase; and increased concentrations of triglycerides and uric acid. Postmortem examination revealed that the chickens fed CPA or OA-CPA had thickened mucosa and dilated proventricular lumen. Data from this study demonstrate that OA, CPA, and the OA-CPA combination can limit broiler performance and adversely affect broiler health. The interaction of the compounds was primarily additive or less than additive in the parameter in which the interaction occurred.

Effects of a hydrated sodium calcium aluminosilicate (T-Bind) on mycotoxicosis in young broiler chickens

Experiments were conducted to determine the ability of a hydrated sodium calcium aluminosilicate (T-Bind) sorbent to reduce the toxicity of aflatoxins (AF) or T-2 toxin in male broiler chickens from day of hatch to 21 d of age. In Experiment 1, the sorbent was added at 0.250 or 0.375% to diets containing AF at 5 or T-2 toxin at 8 mg/kg of diet. When compared with controls, AF reduced BW gain by 27% and T-2 toxin reduced BW gain by 17%. The addition of the sorbent at 0.250 or 0.375%, in the absence of added mycotoxins, did not alter the performance of the chicks. The sorbent reduced the toxic effects of 5 mg AF/kg of diet on BW gain by 43% but did not significantly diminish the toxic effects of 8 mg T-2 toxin/kg of diet. The decreased efficiency of feed utilization and the increased relative organ weights caused by AF were significantly diminished to differing degrees by the sorbent. Oral lesions caused by T-2 toxin were not affected by the sorbent. In Experiment 2, the sorbent was added at 0.80% to a diet containing 8 mg T-2 toxin/kg of diet. The sorbent did not diminish the toxic effects of T-2 toxin when added at 0.80% of the diet. These data demonstrate that this specific sorbent can provide protection against the toxicity of AF, but not T-2 toxin, in young broiler chicks.

Aflatoxicosis in turkey poults is prevented by treatment of naturally contaminated corn with ozone generated by electrolysis

Previous studies have demonstrated that a novel source of ozone gas (O3) maybe used to chemically degrade numerous mycotoxins, including aflatoxin (AF) B1. Subsequent in vitro analyses demonstrated detoxification of AFB1, suggesting a potential method of remediate AF-contaminated grain. The objective of this study was to evaluate the capability of electrochemically produced ozone to degrade AFB1 in naturally contaminated whole kernel corn and confirm detoxification in turkey poults. Corn was procured from the southern coastal areas of Texas and HPLC revealed 1,220 +/- 73.3 ppb AFB1. Control and contaminated corn were treated for 92 h with O3 at 200 mg/min in 30 kg batches; greater than 95% reduction of AFB1 in contaminated corn was achieved. One-day-old female turkey poults were fed 1) control corn, 2) control corn + O3, 3) AFB1 corn, or 4) AFB1 corn + O3 mixed in rations (46% by wt.) and consumed ad libitum for 3 wk. When compared with controls, turkeys fed AFB1 corn had reduced body weight gain and relative liver weight, whereas turkeys fed control corn + O3 or AFB1 corn + O3 did not differ from controls. Furthermore, alterations in the majority of relative organ weight, liver discoloration, serum enzyme activity, hematological parameters, and blood chemistry caused by AFB1 were eliminated (no difference from controls) by treatment with O3. These data demonstrate that treatment of contaminated corn with electrochemically produced O3 provided protection against AFB1 in young turkey poults. It is important to note that treatment of control corn with O3 did not alter the performance of the turkey poults.

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.

Effects of inorganic adsorbents and cyclopiazonic acid in broiler chickens

Previous studies with cyclopiazonic acid (CPA) have indicated that this mycotoxin strongly adsorbs onto the surface of a naturally acidic phyllosilicate clay (AC). The objective of this study was to determine whether AC (and similar adsorbents) could protect against the toxicity of CPA in vivo. Acidic phyllosilicate clay, neutral phyllosilicate clay (NC, or hydrated sodium calcium aluminosilicate), and a common zeolite (CZ, or clinoptilolite) were evaluated. One-day-old broiler chicks consumed diets containing 0 or 45 mg/kg CPA alone or in combination with 1% AC, NC, or CZ ad libitum from Day 1 to 21. Body weight, feed consumption, feed:gain, hematology, serum biochemical values, and enzyme activities were evaluated. Compared to controls, CPA alone reduced body weight at Day 21 by a total of 26% and resulted in a significantly higher feed:gain ratio. Toxicity of CPA was also expressed through increased relative weights of kidney, proventriculus, and gizzard. Also, there were some alterations in hematology, serum biochemical values, and enzyme activities. Treatment with inorganic adsorbents did not effectively diminish the growth-inhibitory effects of CPA or the increased weights of organs, although there was some protection from hematological, serum biochemical, and enzymatic changes produced by CPA. The results of this study suggest that in vitro binding of CPA to clay does not accurately forecast its efficacy in vivo; the reasons for this discrepancy are not clear, but they may be related to differences in clay binding capacity and ligand selectivity for CPA in vitro vs in vivo. Predictions about the ability of inorganic adsorbents to protect chickens from the adverse effects of mycotoxins should be approached with caution and should be confirmed in vivo, paying particular attention to the potential for nutrient interactions.

Individual and combined effects of fumonisin B1 present in Fusarium moniliforme culture material and diacetoxyscirpenol or ochratoxin A in turkey poults

The individual and combined effects of feeding diets containing 300 mg fumonisin B1 (FB1), and 4 mg diacetoxyscirpenol (DAS) or 3 mg ochratoxin A (OA) were evaluated in two experiments using female turkey poults (Nicholas Large Whites) from day of hatch to 3 wk of age. When compared with controls, body weight gains were reduced 30% (Study 1) and 24% (Study 2) by FB1, 30% by DAS, 8% by OA, 46% by the FB1 and DAS combination, and 37% by the FB1 and OA combination. The efficiency of feed utilization was adversely affected by all treatments except FB1 in Experiment 2. Relative weights of the liver were significantly increased by all treatments except the DAS treatment. Serum concentrations of cholesterol were decreased and activities of aspartate aminotransferase and lactate dehydrogenase were increased and several hematological values were altered in poults fed FB1 alone and in combination with either DAS or OA. Results indicate additive or less than additive toxicity, but not toxic synergy, when poults are fed diets containing 300 mg FB1, and 4 mg DAS or 3 mg OA/kg of diet. The likelihood of encountering FB1, DAS, or OA at these concentrations in finished feed is small. However, under field conditions, other stress factors could alter the impact of these mycotoxins on the health and performance of poultry.

T-2 tetraol is cytotoxic to a chicken macrophage cell line

Cytotoxic effects of T-2 tetraol, a T-2 toxin derivative, on the MQ-NCSU chicken macrophage cell line were quantified by direct in vitro exposure. Macrophage cultures were exposed to 1, 10, 20, 40, 80, 160, and 320 micrograms/mL of T-2 tetraol for 1 h. Macrophage viability after exposure to T-2 tetraol. Macrophage viability was reduced by increasing concentrations of T-2 tetraol (linear effect, P < or = 0.001; quadratic effect, P < or = 0.025). The ability of macrophages to adhere to glass surfaces was impaired by increasing concentrations of T-2 tetraol (linear effect, P < or = 0.003). This experiment demonstrates that T-2 tetraol is cytotoxic to chicken macrophages in vitro.

Influence of fumonisin B1, present in Fusarium moniliforme culture material, and T-2 toxin on turkey poults

Diets containing 300 mg fumonisin B1 (FB1)/kg of feed and 5 mg T-2 toxin/kg of feed singly or in combination were fed to female turkey poults (Nicholas Large White) from day of hatch to 21 d of age. When compared with controls, 21-d body weight gains were reduced 21% by FB1, 26% by T-2, and 47% by the combination. the efficiency of feed utilization was adversely affected by FB1 and the combination of FB1 and T-2. Relative weights (grams/100 g BW) of the liver and gizzard were increased in poults fed the FB1 and the combination diets; whereas, the relative weight of the pancreas was increased in all treated groups. All poults were scored for oral lesions using a scale of 1 to 4 (1 = no visible lesions, 4 = severe lesions). Oral lesions were present in all poults fed the T-2 diet (average score of 3.29) or the combination diet (average score of 3.54). Serum concentration of cholesterol was decreased and lactate dehydrogenase activity was increased in poults fed the FB1 and combination diets. The activity of aspartate aminotransferase and the values for red blood cells, hemoglobin, and hematocrit were increased only in poults fed the combination diet. Inorganic phosphorus concentration was decreased only in poults fed the combination diet. The increased toxicity in poults fed the combination diet for most variables can best be described as additive, although some variables not altered by FB1 or T-2 singly were significantly affected by the combination, indicating that the combination may pose a potentially greater problem to the turkey industry than either of the mycotoxins individually.