Subacute toxicity of T-2 toxin in broiler chicks

Sodium selenite (Na2SeO3) attenuates T-2 toxin-induced iron death in LMH cells through the ROS/PI3K/AKT/Nrf2 pathway

T-2 toxin, is a monotrichous mycotoxin commonly found in animal feed and agricultural products that can damage tissues and organs through oxidative stress. Selenium is a trace element with favorable antioxidant effects. However, it is unclear whether T-2 toxin-induces ferroptosis in LMH cells and whether Na2SeO3 has a protective role in this process. To investigate the process of hepatic injury by T-2 toxin and its antagonistic effect by Na2SeO3, we used 20 ng/mL T-2 toxin as well as 160 nmol/L Na2SeO3 to treat the LMH cells. The results demonstrated that exposure to the T-2 toxin induced iron death by increasing the quantity of ROS, leading to oxidative damage, decreasing the quantities of SOD, GPx, and T-AOC, and increasing the accumulation of MDA and H2O2, which resulted in the accumulation of Fe2+ and the down-regulation of the manifestation of linked genes and proteins including FTH1, Gpx4, NQO-1, and HO-1. After the addition of Na2SeO3, the PI3K/AKT/Nrf2 pathway is activated by regulating the selenoproteins gene level, and the above abnormal changes are reversed. In summary, Na2SeO3 alleviated T-2 toxin-induced iron death via the PI3K/AKT/Nrf2 pathway. These study not only broaden the cytotoxic knowledge regarding T-2 toxin, but also serve as a foundation for the use of Na2SeO3 in daily life.

T-2 toxin-induced intestinal damage with dysregulation of metabolism, redox homeostasis, inflammation, and apoptosis in chicks

T-2 toxin is a worldwide problem for feed and food safety, leading to livestock and human health risks. The objective of this study was to explore the mechanism of T-2 toxin-induced small intestine injury in broilers by integrating the advanced microbiomic, metabolomic and transcriptomic technologies. Four groups of 1-day-old male broilers (n = 4 cages/group, 6 birds/cage) were fed a control diet and control diet supplemented with T-2 toxin at 1.0, 3.0, and 6.0 mg/kg, respectively, for 2 weeks. Compared with the control, dietary T-2 toxin reduced feed intake, body weight gain, feed conversion ratio, and the apparent metabolic rates and induced histopathological lesions in the small intestine to varying degrees by different doses. Furthermore, the T-2 toxin decreased the activities of glutathione peroxidase, thioredoxin reductase and total antioxidant capacity but increased the concentrations of protein carbonyl and malondialdehyde in the duodenum in a dose-dependent manner. Moreover, the integrated microbiomic, metabolomic and transcriptomic analysis results revealed that the microbes, metabolites, and transcripts were primarily involved in the regulation of nucleotide and glycerophospholipid metabolism, redox homeostasis, inflammation, and apoptosis were related to the T-2 toxin-induced intestinal damage. In summary, the present study systematically elucidated the intestinal toxic mechanisms of T-2 toxin, which provides novel ideas to develop a detoxification strategy for T-2 toxin in animals.

Effects of T-2 toxin on growth performance, feather quality, tibia development and blood parameters in Yangzhou goslings

T-2 toxin is a dangerous natural pollutant and widely exists in animal feed, often causing toxic damage to poultry, such as slow growth and development, immunosuppression, and death. Although geese are considered the most sensitive poultry to T-2 toxin, the exact damage caused by T-2 toxin to geese is elusive. In the present study, a total of forty two 1-day-old healthy Yangzhou male goslings were randomly allotted seven diets contaminated with 0, 0.2, 0.4, 0.6, 0.8, 1.0, or 2.0 mg/kg T-2 toxin for 21 d, and the effects of T-2 toxin exposure on growth performance, feather quality, tibia development, and blood parameters were investigated. The results showed that T-2 toxin exposure significantly inhibited feed intake, body weight gain, shank length growth, and organ development (e.g., ileum, cecum, liver, spleen, bursa, and tibia) in a dose-dependent manner. In addition, the more serious feathering abnormalities and feather damage were observed in goslings exposed to a high dose of T-2 toxin (0.8, 1.0, and 2.0 mg/kg), which were mainly sparsely covered with short, dry, rough, curly, and gloss-free feathers on the back. We also found that hypertrophic chondrocytes of the tibial growth plate exhibited abnormal morphology and nuclear consolidation or loss, accompanied by necrosis and excessive apoptosis under 2.0 mg/kg T-2 toxin exposure. Moreover, 2.0 mg/kg T-2 toxin exposure triggered erythropenia, thrombocytosis, alanine aminotransferase, and aspartate aminotransferase activity, as well as high blood urea nitrogen, uric acid, and lactic dehydrogenase levels. Collectively, these data indicate that T-2 toxin had an adverse effect on the growth performance, feather quality, and tibia development, and caused liver and kidney damage and abnormal blood parameters in Yangzhou goslings, providing crucial information toward the prevention and control of T-2 toxin contamination in poultry feed.

Mandated restrictions on the use of medically important antibiotics in broiler chicken production in Canada: implications, emerging challenges, and opportunities for bolstering gastrointestinal function and health– A review

Chicken Farmers of Canada has been progressively phasing out prophylactic use of antibiotics in broiler chicken production. Consequently, hatcheries, veterinarians, and nutritionists have been mandated to contend with less reliance on use of preventive antibiotics. A topical concern is the increased risk of proliferation of enteric pathogens leading to poor performance, increased mortality and compromised welfare. Moreover, the gut harbors several taxa such as Campylobacter and Salmonella capable of causing significant illnesses in humans via contaminated poultry products. This has created opportunity for research and development of dietary strategies designed to modulate gastrointestinal environment for enhanced performance and food safety. Albeit with inconsistent responses, literature data suggests that dietary strategies such as feed enzymes, probiotics/prebiotics and phytogenic feed additives can bolster gut health and function in broiler chickens. However, much of the efficacy data was generated at controlled research settings that vary significantly with the complex commercial broiler production operations due to variation in dietary, health and environmental conditions. This review will summarize implications of mandated restrictions on the preventative use of antibiotics and emerging Canadian broiler production programs to meet processor specifications. Challenges and opportunities for integrating alternative dietary strategies in commercial broiler production settings will be highlighted.

T-2 Toxin Induces Oxidative Stress, Apoptosis and Cytoprotective Autophagy in Chicken Hepatocytes

T-2 toxin is type A trichothecenes mycotoxin, which produced by fusarium species in cereal grains. T-2 toxin has been shown to induce a series of toxic effects on the health of human and animal, such as immunosuppression and carcinogenesis. Previous study has proven that T-2 toxin caused hepatotoxicity in chicken, but the regulatory mechanism is unclear. In the present study, we assessed the toxicological effect of T-2 toxin on apoptosis and autophagy in hepatocytes. The total of 120 1-day-old healthy broilers were allocated randomly into four groups and reared for 21 day with complete feed containing 0 mg/kg, 0.5 mg/kg, 1 mg/kg or 2 mg/kg T-2 toxin, respectively. The results showed that the apoptosis rate and pathological changes degree hepatocytes were aggravated with the increase of T-2 toxin. At the molecular mechanism level, T-2 toxin induced mitochondria-mediated apoptosis by producing reactive oxygen species, promoting cytochrome c translocation between the mitochondria and cytoplasm, and thus promoting apoptosomes formation. Meanwhile, the expression of the autophagy-related protein, ATG5, ATG7 and Beclin-1, and the LC3-II/LC3-I ratio were increased, while p62 was downregulated, suggesting T-2 toxin caused autophagy in hepatocytes. Further experiments demonstrated that the PI3K/AKT/mTOR signal may be participated in autophagy induced by T-2 toxin in chicken hepatocytes. These data suggest a possible underlying molecular mechanism for T-2 toxin that induces apoptosis and autophagy in chicken hepatocytes.

The response of glandular gastric transcriptome to T-2 toxin in chicks

This study was conducted to determine the effect of T-2 toxin on the transcriptome of the glandular stomach in chicks using RNA-sequencing (RNA-Seq). Four groups of 1-day-old Cobb male broilers (n = 4 cages/group, 6 chicks/cage) were fed a corn-soybean-based diet (control) and control supplemented with T-2 toxin at 1.0, 3.0, and 6.0 mg/kg, respectively, for 2 weeks. The histological results showed that dietary supplementation of T-2 toxin at 3.0 and 6.0 mg/kg induced glandular gastric injury including serious inflammation, increased inflammatory cells, mucosal edema, and necrosis and desquamation of the epithelial cells in the glandular stomach of chicks. RNA-Seq analysis revealed that there were 671, 1393, and 1394 genes displayed ≥2 (P < 0.05) differential expression in the dietary supplemental T-2 toxin at 1.0, 3.0, and 6.0 mg/kg, respectively, compared with the control group. Notably, 204 differently expressed genes had shared similar changes among these three doses of T-2 toxin. GO and KEGG pathway analysis results showed that many genes involved in oxidation-reduction process, inflammation, wound healing/bleeding, and apoptosis/carcinogenesis were affected by T-2 toxin exposure. In conclusion, this study systematically elucidated toxic mechanisms of T-2 toxin on the glandular stomach, which might provide novel ideas to prevent adverse effects of T-2 toxin in chicks.

A Novel Modified Hydrated Sodium Calcium Aluminosilicate (HSCAS) Adsorbent Can Effectively Reduce T-2 Toxin-Induced Toxicity in Growth Performance, Nutrient Digestibility, Serum Biochemistry, and Small Intestinal Morphology in Chicks

The objective of this study was to evaluate the ability of a modified hydrated sodium calcium aluminosilicate (HSCAS) adsorbent to reduce the toxicity of T-2 toxin in broilers. Ninety-six one-day-old male broilers were randomly allocated into four experimental groups with four replicates of six birds each. The four groups, 1–4, received a basal diet (BD), a BD plus 6.0 mg/kg T-2 toxin, a BD plus 6.0 mg/kg T-2 toxin with 0.05% modified HSCAS adsorbent, and a BD plus 0.05% modified HSCAS adsorbent, respectively, for two weeks. Growth performance, nutrient digestibility, serum biochemistry, and small intestinal histopathology were analyzed. Compared to the control group, dietary supplementation of T-2 toxin decreased (p < 0.05) body weight gain, feed intake, and the feed conversion ratio by 11.4–31.8% during the whole experiment. It also decreased (p < 0.05) the apparent metabolic rates of crude protein, calcium, and total phosphorus by 14.9–16.1%. The alterations induced by T-2 toxin were mitigated (p < 0.05) by the supplementation of the modified HSCAS adsorbent. Meanwhile, dietary modified HSCAS adsorbent supplementation prevented (p < 0.05) increased serum aspartate aminotransferase by T-2 toxin at d 14. It also prevented (p < 0.05) T-2 toxin-induced morphological changes and damage in the duodenum, jejunum, and ileum of broilers. However, dietary supplementation of the modified HSCAS adsorbent alone did not affect (p > 0.05) any of these variables. In conclusion, these findings indicate that the modified HSCAS adsorbent could be used against T-2 toxin-induced toxicity in growth performance, nutrient digestibility, and hepatic and small intestinal injuries in chicks.

Role of Glutathione Redox System on the T-2 Toxin Tolerance of Pheasant (Phasianus colchicus)

The purpose of the present study was to evaluate the effects of different dietary concentrations of T-2 toxin on blood plasma protein content, lipid peroxidation and glutathione redox system of pheasant (Phasianus colchicus). A total of 320 one-day-old female pheasants were randomly assigned to four treatment groups fed with a diet contaminated with different concentrations of T-2 toxin (control, 4 mg/kg, 8 mg/kg and 16 mg/kg). Birds were sacrificed at early (12, 24 and 72 hr) and late (1, 2 and 3 weeks) stages of the experiment to demonstrate the effect of T-2 toxin on lipid peroxidation and glutathione redox status in different tissues. Feed refusal and impaired growth were observed with dose dependent manner. Lipid-peroxidation was not induced in the liver, while the glutathione redox system was activated partly in the liver, but primarily in the blood plasma. Glutathione peroxidase activity has changed parallel with reduced glutathione concentration in all tissues. Based on our results, pheasants seem to have higher tolerance to T-2 toxin than other avian species, and glutathione redox system might contribute in some extent to this higher tolerance, in particular against free-radical mediated oxidative damage of tissues, such as liver.

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.

Current situation of mycotoxin contamination and co-occurrence in animal feed--focus on Europe

Mycotoxins are secondary metabolites produced by fungi especially those belonging to the genus Aspergillus, Penicillum and Fusarium. Mycotoxin contamination can occur in all agricultural commodities in the field and/or during storage, if conditions are favourable to fungal growth. Regarding animal feed, five mycotoxins (aflatoxins, deoxynivalenol, zearalenone, fumonisins and ochratoxin A) are covered by EU legislation (regulation or recommendation). Transgressions of these limits are rarely observed in official monitoring programs. However, low level contamination by Fusarium toxins is very common (e.g., deoxynivalenol (DON) is typically found in more than 50% of the samples) and co-contamination is frequently observed. Multi-mycotoxin studies reported 75%-100% of the samples to contain more than one mycotoxin which could impact animal health at already low doses. Co-occurrence of mycotoxins is likely to arise for at least three different reasons (i) most fungi are able to simultaneously produce a number of mycotoxins, (ii) commodities can be contaminated by several fungi, and (iii) completed feed is made from various commodities. In the present paper, we reviewed the data published since 2004 concerning the contamination of animal feed with single or combinations of mycotoxins and highlighted the occurrence of these co-contaminations.

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.

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.

Apoptose na depleção linfocitária induzida pela toxina T-2 em frangos de corte. Histomorfometria da bolsa de Fabricius

Estudou-se, pela histomorfometria da bolsa de Fabrício, o envolvimento da apoptose como mecanismo de depleção linfocitária em frangos de corte, após ingestão de toxina T-2 de Fusarium sporotrichioides veiculada pela ração. Foram utilizados 42 pintos de um dia de idade, distribuídos ao acaso em três grupos. O grupo tratado (n = 15) recebeu diariamente ração contaminada com 2,64 mg/kg da toxina T-2; o grupo residual (n = 12) recebeu ração contaminada por 7 ou 14 dias, passando a receber ração limpa (não contaminada) na semana antecedente ao sacrifício. Um grupo controle (n = 15) recebeu ração não contaminada. Aos 7, 14 e 21 dias de experimento cinco animais de cada um dos grupos controle e tratado e aos 14 e 21dias seis do grupo residual foram sacrificados, colhendo-se as bolsas de Fabrício (BF) para análise histomorfométrica e determinação do índice apoptótico. As características da apoptose foram confirmadas pela técnica de marcação in situ da fragmentação do genoma (TUNEL) e pela eletroforese do DNA, em gel de agarose. As BF nos grupos tratado e residual, aos 14 e 21 dias, apresentaram depleção linfocitária de moderada a intensa e elevado índice apoptótico, significativamente maior do que do grupo controle (P<0,05). Os resultados permitem concluir que a apoptose está envolvida no mecanismo da depleção linfocitária provocada pela toxina T-2, em frangos de corte.

Effect of dietary T-2 fusariotoxin concentrations on the health and production of white Pekin duck broilers

The effects of different dietary levels of T-2 toxin on production, biological, immunological, and pathological parameters of growing white Pekin ducks were studied to establish the "no effect" dietary concentration of, and "no effect" exposure time to, pure T-2 toxin. Day-old white Pekin ducks were randomly allotted to nine groups of 10 ducks each. One group served as a control, and no mycotoxin was added to its feed. The feeds of the experimental groups were supplemented with 0.2, 0.4, 0.6, 0.8, 1.0, 2.0, 3.0, and 4.0 mg purified T-2 toxin/kg, respectively, from Day 1 until Day 49 of the experiment. Dermatotoxic oral lesions developed in most experimental ducks within 2 d after the start of feeding T-2 toxin-contaminated feeds. The gradual disappearance of macroscopic signs indicated the development of tolerance in groups treated with the lower T-2 toxin content. No repair was found in the 3 and 4 mg/kg groups. Dietary concentrations of T-2 toxin below 0.4 mg/kg had no effect on the average weekly weight gain in the first 6 wk, but a severe decrease was found in the last week of the experiment. The 0.6 mg/kg dietary T-2 toxin had no effect on weight gain in the first 3 wk. At Week 4 and later, the weekly weight gain was significantly reduced, and the final live weight of this group was also significantly lower than that of the control. Dietary T-2 concentrations of 1 mg/kg and greater uniformly depressed growth rate. Only the 3 and 4 mg/kg groups refused feed during the first week. From Week 3 on, the feed intakes of the 0.6 to 4 mg/kg groups were usually less than that of the control group, indicating feed refusal. Serum and plasma chemical values and hematological parameters failed to show dose-dependent effects. The blastogenic response of lymphocytes to nonspecific and specific mitogens was distinctly impaired by the T-2 toxin at all levels in the feed. In the 3 and 4 mg/kg groups, the histological examination revealed lymphocyte depletion in the spleen and bursa of Fabricius.

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.

4 beta, 15-Diacetoxyscirpenol induces cytotoxicity and alterations in phagocytic and Fc-receptor expression functions in chicken macrophages in vitro

4 beta, 15 Diacetoxyscirpenol (DAS) mycotoxin produced by Fusarium species was tested for detrimental effects on macrophage viability, phagocytosis, and Fc-receptor expression. Sephadex-elicited chicken abdominal cells were harvested to establish adherent macrophage monolayers on glass coverslips. Coverslips were then assigned randomly to treatment groups (0, 12.5 and 25 micrograms/mL DAS). Macrophage monolayers were exposed to treatments for 1 h, washed, and tested for various functional endpoints. Treatment with DAS resulted in decreased viability of macrophages (90.8% vs 81.5% vs 70.4% viable in the 0, 12.5 and 25 micrograms treatments, respectively) and decreased the percentage of macrophages phagocytizing sheep erythrocytes (81.6% vs 53.1% vs 46.0%. DAS also caused a decrease in the mean number of opsonized cells engulfed per phagocytic macrophage (5.7 vs 3.7 vs 2.9). A similar trend was observed using unopsonized sheep erythrocytes (15.4% vs 7.6% vs 5.5% phagocytic macrophages and 0.29 vs 0.11 vs 0.08 erythrocytes engulfed per macrophage). The incidence of Fc-receptor positive macrophages determined by sheep erythrocyte rosetting was also decreased in DAS-treated macrophages as compared to the control (49.2% vs 32.7% vs 24.2%). The findings of this study demonstrate that DAS exposure causes a suppression in macrophage phagocytic function and therefore may alter the first line of immunological defense in chickens.

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.

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.

Alteration of major cytokines produced by mitogen-activated peritoneal macrophages and splenocytes in T-2 toxin-treated male CD-1 mice

Fusarium T-2 toxin has immunotoxic properties that may be related to the modulation of cytokine expression by cells of the immune system. Male CD-1 mice were used to study the effect of in vivo exposure to T-2 toxin on the alteration of interleukin (IL)-1α, tumor necrosis factor α (TNF), and IL-6 in lipopolysaccharide-stimulated peritoneal macrophages, and IL-2, IL-3, and interferon γ (IFNγ) in concanavalin A (Con A)-stimulated splenocytes. Mice were orally dosed with 0, 0.1, 0.5, and 2.5 mg T-2 toxin/kg body weight for 2 weeks on alternate days. Northern blot analysis of IL-1α, TNF, and IL-6 mRNA from activated peritoneal macrophages showed no significant differences between control and treated groups. Measurements of secreted protein by immunoassay demonstrated suppression of these cytokines in all treated groups, suggesting that T-2 toxin affects the translational or post-translational regulation of these cytokines from peritoneal macrophages. Levels of IL-2, IL-3, and IFNγ mRNA from Con A-activated splenocytes were higher in all treated groups. The increases were significant for IL-2 and IFNγ in the groups receiving low (0.1 mg/kg) and high (2.5 mg/kg) doses of T-2 toxin, and for IL-3 in the group receiving a medium (0.5 mg/kg) dose of this toxin (P ≤ 0.05). Results indicated that T-2 toxin given orally at low or medium doses induces transcription or increases mRNA stability of IL-2, IFNγ, and IL-3. Protein levels of all three cytokines were also increased, indicating that T-2 toxin also increases translational/post-translational efficiency of IFNγ, IL-2, and IL-3. Possible mechanisms in the immunosuppressive effects of T-2 toxin may involve endotoxemia resulting after the toxin administration, alteration of the stability of mRNA, or previously described effects of T-2 toxin on protein synthesis.

Nivalenol in Swedish cereals--occurrence, production and toxicity towards chickens

Nivalenol has been analysed in Swedish cereals between 1987 and 1990 and it was found in oats (35% of all samples), barley (13%) and wheat (4%), with a high yearly variation. The highest concentration was 4700 micrograms/kg. Nivalenol-producing strains of Fusarium poae were isolated from contaminated samples. Feeding nivalenol to chicks produced no toxic effects at concentrations below 5 mg/kg and only small effects at 6 and 12 mg/kg.

Effects of feeding nivalenol-contaminated diets to male broiler chickens

In two feeding trials the effect of nivalenol (NIV) on male broiler chickens was studied. A commercial starter diet was provided for ad libitum consumption throughout the whole experiment. The NIV was added to the feed when the birds were 7 d old. Growth and feed consumption were thereafter registered every 5th d during 20 d. In the first trial birds were offered feed containing 0, .5, 2.5, or 5 ppm NIV. The only variable that significantly differed from the control was the concentration of uric acid in plasma, which was increased by 94 and 66%, respectively, in treatment groups 2.5 and 5 ppm. In the second trial, NIV-concentrations of 0, 3, 6, and 12 ppm were used. The weight gain for the 20-d period was decreased by 11% with 6 and 12 ppm. During this period these birds showed a decrease of about 6% in feed consumption and feed conversion efficiency. Gizzard erosions were found in 33% of the birds fed 12 ppm NIV and in 8% of those fed 3 or 6 ppm. No such erosions were found in the control birds. Relatively, the liver weights in the 12 ppm group were reduced more than total body weights. No effects on relative organ weights were found when bursa, spleen, and gizzard were compared to control. In the blood, no change compared to control was found in hematocrit or in the plasma concentration of glucose, calcium, cholesterol, triglycerides, and uric acid, or in the plasma activity of aspartate amino transferase, alanine amino transferase, or gamma glutamyl transpeptidase.

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.

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

The effects of feeding 6 mg T-2 toxin (T-2) and 34 mg cyclopiazonic acid (CPA)/kg of diet singly and in combination were characterized in male broiler chicks from 1 d to 3 wk of age. Body weights were depressed by T-2, CPA, and the combination of T-2 and CPA. There was a significant synergistic interaction between T-2 and CPA for relative liver and kidney weights and serum cholesterol and triglyceride concentrations and a significant interaction between T-2 and CPA for 3-wk body weights and relative bursa of Fabricius weights, which were less than additive. Neither the efficiency of feed utilization nor mortality was affected by dietary treatments. Oral lesions were present in a majority of the chicks fed diets containing T-2 with or without CPA. When compared with controls, other variables measured exhibited additive or less than additive toxicity. These data demonstrate that T-2 and CPA alone and in combination can cause reduced performance and adversely affect broiler health. The effects of these mycotoxins may be exacerbated by other factors when under field conditions; hence, the potential detrimental effects of these two mycotoxins when present alone or in combination cannot be dismissed.

Individual and combined effects of T-2 toxin and DAS in laying hens

1. The individual and combined effects of T-2 toxin and 4,15-diacetoxyscirpenol (DAS) on laying hens were investigated in an experiment consisting of a 2 x 2 completely randomised factorial design with dietary concentrations of 0 and 2 mg/kg T-2 toxin and 0 and 2 mg/kg DAS. 2. Individually, T-2 toxin and DAS induced oral lesions in half of the hens and decreased significantly egg production and food intake. 3. The effects of T-2 toxin and DAS were additive for reduced food consumption and incidence of oral lesions. However, a synergism for reduced egg production was observed during the last experimental period. 4. No effects on body weight were observed during this study. Mild changes in selected plasma enzymes activities and no change in liver malondialdehyde content were detected. 5. The combination of T-2 toxin and DAS was more toxic than the single mycotoxins, for some parameters, and therefore, may pose a greater economic threat to the poultry industry than either of the toxins individually.

Mouth lesions in broiler chickens caused by scirpenol mycotoxins

Dietary scirpentriol (STO), triacetoxyscirpenol (TAS), monoacetoxyscirpenol (MAS), and diacetoxyscirpenol (DAS), mycotoxins produced by Fusarium species, were compared for their ability to cause mouth lesions when graded dietary levels (0, 1, 2, 4, and 8 micrograms STO or TAS/g; 0, .5, 1, 2, and 4 micrograms MAS or DAS/g) were fed to male broiler chickens for 21 days after hatching. The mouth lesions provoked by each scirpenol were dose-related. The minimum effective doses (MED) were 4, 2, 1, and .5 micrograms/g for TAS, STO, DAS, and MAS, respectively, whether the number of affected birds or the number of affected mouth parts (angles, upper beak, lower beak, and tongue) was the measured response. Lesion sites in the mouth varied with the toxin. The rank orders from greatest to least affected sites were angles, upper beak, lower beak, and tongue for TAS and STO, upper beak, lower beak, angles, and tongue for MAS, and upper beak, lower beak, tongue, and angles for DAS. Mouth lesions were clearly visible with each toxin after feeding for 1 wk and the numbers of affected mouth parts almost tripled after 2 wk exposure. During Week 3 of exposure, only the increase caused by MAS was significant (P less than .05). The MED for growth inhibition were 2, 2, 2, and 8 micrograms/g for STO, MAS, DAS, and TAS, respectively. Thus, mouth lesions were of equal or greater sensitivity than growth inhibition as an indicator of scirpenol toxicity. It would appear that the discovery of mouth lesions in birds justifies a mold and mycotoxin control program.

Comparative fate of the tritiated trichothecene mycotoxin, T-2 toxin, in chickens and ducks

A tritiated preparation of the trichothecene mycotoxin, T-2 toxin, was administered as a single oral dose to 21-day-old male broiler (Hubbard x Hubbard) chickens and White Pekin ducks. There were few significant differences between the two species in metabolism, tissue retention, and excretion of T-2 toxin and its metabolites. On the basis of the data obtained, the differences in toxicological sensitivity to T-2 toxin known to exist between these two species cannot likely be attributed to differences in the metabolism or elimination of T-2 toxin from the body.

Efficacy of a hydrated sodium calcium aluminosilicate to reduce the toxicity of aflatoxin and T-2 toxin

A hydrated sodium calcium aluminosilicate (HSCAS) was incorporated into diets (.5%) containing 3.5 mg of aflatoxin (AF) per kg and 8.0 mg of T-2 toxin (T-2) per kg, singly, and in combination. Male broiler chicks (n = 480) were provided with feed and water for ad libitum consumption from 1 to 21 days of age. Body weight gains were significantly depressed by AF and T-2, singly, and further decreased by the combination of the two toxins. Efficiency of feed utilization was not affected. The AF alone and the AF plus T-2 combination caused increases in relative liver, kidney, proventriculus, gizzard, spleen, and pancreas weights. Treatment-related changes in hematological and serum biochemical values and enzyme activities were observed. Oral lesions were observed only in chicks receiving the T-2 diets. The HSCAS fed singly did not alter any of the parameters measured but it did diminish the toxicity of AF for many parameters but did not appear to alter the toxicity of T-2. Addition of HSCAS to the AF plus T-2 combination diet diminished some of the effects of the toxin combination. These findings indicate that HSCAS can diminish many of the adverse effects of dietary AF in the chicken, but it has no effect on T-2 toxicity.

Influence of ochratoxin A and T-2 toxin singly and in combination on broiler chickens

Effects of feeding diets containing ochratoxin A (OA) at 2.0 mg/kg and T-2 toxin at 4.0 mg/kg singly and in combination were characterized in male broiler chicks from 1 day to 3 wk of age. Body weights were depressed by feeding OA singly, T-2 singly, and the OA/T-2 combination. The efficiency of feed utilization was reduced in the OA and OA/T-2 combination-fed groups. The T-2 toxin caused oral lesions, anemia, and changes in some serum biochemical values. Feeding OA resulted in increases in relative liver, kidney, gizzard, and pancreas weights, a microcytic hypochromic anemia, and changed serum chemistries. The OA/T-2 combination caused increases in relative liver, kidney, proventriculus, and gizzard weights and variable serum biochemistries. The effects of OA and T-2 were additive for reduced body weight gains, mean corpuscular volume, and for reduced serum levels of total protein, and for reduced lactate dehydrogenase activity. A significant interaction occurred between OA and T-2 causing elevated serum triglyceride levels and decreased gamma glutamyl transferase activity and calcium levels. Degenerative renal tubular changes were observed in some OA and OA/T-2 combination-fed chicks. These data indicate that OA and T-2 in combination may be more toxic for some parameters than the individual mycotoxins, and may pose a greater problem for the poultry industry than either of the mycotoxins individually.

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

Effects of feeding diets containing deoxynivalenol (DON)-contaminated wheat (16 mg DON/kg) and purified T-2 toxin at 4 mg/kg singly and in combination were characterized in male broiler chicks from 1 day to 3 wk of age. Total body weight gains and final body weights were significantly reduced by the DON/T-2 toxin combination but were not significantly affected by the toxins singly. The efficiency of feed utilization was reduced in chicks fed either of the diets containing DON-contaminated wheat. The incidence and severity of oral lesions induced by T-2 toxin was increased in the DON/T-2 toxin combination. Several parameters not altered by DON or T-2 toxin singly were significantly affected by the combination, indicating that the combination may pose a potentially greater problem to the poultry industry than either of the mycotoxins individually.

LD50 values and serum biochemical changes induced by T-2 toxin in rats and rabbits

Experiments were conducted to study the acute and subacute effects of intramuscularly injected T-2 toxin in rats and rabbits. The LD50 values of T-2 toxin were 0.85 +/- 0.03 and 1.10 +/- 0.08 mg/kg body wt in rats and rabbits, respectively. The intoxication was characterized by a consistent decrease in serum alkaline phosphatase (ALP) activity following either a single injection of 0.5, 0.6, or 0.9 mg/kg T-2 toxin in rats or daily injections of 0.2 mg/kg T-2 toxin for 10 days in rats and rabbits. Significant increases in bromosulfalein (BSP) retention and ALP activity were also observed in rabbits 24 hr following a single injection of 0.6 mg/kg T-2 toxin. The results indicated that the hepatobiliary system is a major target organ for T-2 toxin. Alterations in the activity of lactate dehydrogenase (LDH) and creatine kinase (CK) and in the hematocrit values were also observed.

Comparative toxicity of dietary T-2 toxin in rats and mice

The subacute toxic effects of dietary T-2 toxin were compared in young male Wistar rats, young male Swiss mice and juvenile Swiss mice. Purified T-2 toxin was fed in the diet at levels of 10 or 20 ppm for 2 or 4 weeks. Dose-related depressions in food consumption and weight gain consistently occurred in all animals fed T-2 toxin. Hyperkeratosis of the squamous gastric mucosa, atrophy of the thymus and thymus-dependent lymphoid tissues, and lymphopenia occurred in all animals exposed to T-2 toxin. These effects were most severe in juvenile mice, and least severe in rats. In addition, juvenile mice fed the 20-ppm level developed erythroid hypoplasia and became severely anemic by 4 weeks. These results demonstrate that dietary T-2 toxin at levels up to 20 ppm cause similar effects attributable to food refusal and alimentary irritation in both species. However, mice and rats were relatively resistant to hematopoietic suppression. Only the juvenile mice fed 20 ppm developed this potentially lethal toxic effect.

Effects of T-2 toxin on brain catecholamines and selected blood components in growing chickens

Four-week-old male broiler chickens were intubated with a single dose of purified T-2 toxin at 2.5 mg/kg body weight. The brain concentrations of dopamine (DA), norepinephrine (NE), and serotonin (5-HT) and selected blood components were determined in T-2 toxin treated and control chickens at 4, 12, 24, and 48 hr after the toxin treatment. The brain DA concentration of T-2 treated chickens was significantly greater at 12 and 24 hr, whereas brain NE was lower at 24 and 48 hr after toxin treatment as compared with controls. The brain 5-HT level was not altered by T-2 toxin. Serum cholesterol was increased at 4 and 12 hr after T-2 treatment. The serum LDH and GOT activities were not changed by T-2 toxin. T-2 treated chickens had greater packed cell volume and hemoglobin than controls at 24 hr after dosing. Red blood cell counts were not affected but white blood cell counts were decreased during the 12 to 48 hr period after T-2 treatment. The results of this study suggest that T-2 toxin influences brain catecholamines and blood components and thereby possibly brain function in chickens.

Transmission of radioactivity into eggs from laying hens (Gallus domesticus) administered tritium labeled T-2 toxin

The transmission of radioactivity into eggs from laying hens gastric-intubated with a single or multiple dose of 3-[3H]-T-2 toxin was investigated. In single dosed birds, the maximum radioactivity in eggs occurred at 24 hr after dosing; the yolk and white contained .04 and .13% of the administered radioactivity, respectively. In multiple-dosed birds given 8 consecutive daily doses, the radioactivity in the yolk increased with each dose, whereas the radioactivity in the white increased rapidly until the 3rd dose and thereafter remained constant. In both single- and multiple-dosed birds, the specific radioactivity of the white was greater than that of the yolk. The amount of residue transmitted into an egg in birds intubated daily with 1 mg T-2/kg for 8-consecutive days equivalent to 1.6 ppm dietary T-2) was about .9 microgram (based on specific radioactivity).

Necrotic oral lesions in chickens fed diacetoxyscirpenol, T-2 toxin, and crotocin

One-day-old broiler chicks were fed a diet containing either 5 ppm diacetoxyscirpenol (DAS), 5 ppm T-2 toxin, 10 ppm crotocin, or a control diet for 3 weeks. Chicks fed the diet containing DAS and T-2 toxin showed yellowish plaque-type lesions on the beak, tongue, and angle of the mouth. Crotocin did not cause such lesions nor any apparent clinical signs. Chicks fed DAS had the lowest weight gain followed by the T-2, crotocin, and control group in that order; however, chicks fed crotocin had the poorest feed conversion ratio.

Effects of T-2 toxin on reproductive performance and health of laying hens

Purified T-2 toxin was fed to S.C.W.L. hens at levels of 0 (control), 0.5, 1.0, 2.0, 4.0 and 8.0 p.p.m. of an otherwise balanced diet. Feed consumption, egg production and shell thickness were significantly (P less than 0.05) decreased in hens fed 8 p.p.m. as compared with control hens. The fertility and progeny performance were not depressed by feeding T-2 toxin, but the hatchability of fertile eggs of hens fed 2 and 8 p.p.m. was significantly (P less than 0.05) lower than that of hens fed the control diet. The weights of liver, heart, gizzard and spleen were not influenced by T-2 toxin. Serum levels of alkaline phosphatase, LDH and uric acid of hens fed high concentrations of T-2 toxin were greater than those of control hens. SGPT in hens fed 8.0 p.p.m. was lower when compared with control hens. No outward changes in hematocrit, hemoglobin, erythrocyte, leukocyte and differential leukocyte counts were noted with feeding T-2 toxin. Most hens fed T-2 toxin developed oral lesions: circumscribed proliferative yellow caseous plaques at the margin of the beak, mucosa of the hard palate and angle of the mouth, and tongue. The incidence and severity of lesions were proportional to the dietary level of T-2 toxin. The only other lesion observed in necropsy examination at the end of the experiment was the small mucosal ulcer in the anterior portion of the gizzard in hens fed high levels of T-2 toxin. Microscostrointestinal tract, etc.) revealed no significant pathological change except the necrotic lesions in the gizzard and crop.