Effects of the level of feed intake and ergot contaminated concentrate on ruminal fermentation and on physiological parameters in cows.

The aim of the present study was to examine the effects of ergot contaminated feed concentrate at differing levels of feed intake on ruminal fermentation, and on various physiological parameters of dairy cows. Twelve double fistulated (in the rumen and the proximal duodenum) Holstein Friesian cows were fed either a control diet (on a dry matter (DM) base: 60% maize silage, 40% concentrate) or a diet containing ergot alkaloids (concentrate contained 2.25% ergot resulting in an ergot alkaloid concentration of the daily ration between 505 and 620 (µg/kg DM) over a period of four weeks. Daily feed amounts were adjusted to the current performance which resulted in a dry matter intake (DMI) variation between 6.0 and 18.5 kg/day. The resulting ergot alkaloid intake varied between 4.1 and 16.3 (µg/kg body weight when the ergot contaminated concentrate was fed.Concentrations of isovalerate, propionate and ammonia nitrogen in the rumen fluid were significantly influenced by ergot feeding, and the amount of ruminally undegraded protein, as well as the fermentation of neutral detergent fibre, tended to increase with the ergot supplementation at higher levels of feed intake, which might indicate a shift in the microbial population. Other parameters of ruminal fermentation such as ruminai pH, fermented organic matter as a percentage of intake, or the amount of non-ammonia nitrogen measured at the duodenum were not significantly influenced by ergot feeding. The activities of liver enzymes (aspartate aminotransferase, γ-glutamyltransferase, glutamate dehydrogenase, creatine kinase) in the serum were not affected by ergot feeding. The rectal measured body temperature of the cows significantly increased after ergot administration (p=0.019). Thus, body temperature can be regarded as a sensitive parameter to indicate ergot exposure of dairy cows.

On the transfer of the Fusarium toxins deoxynivalenol (DON) and zearalenone (ZON) from sows to their fetuses during days 35-70 of gestation.

Eleven pregnant sows with a body weight between 153 and 197 kg were fed a control diet (CON, 0.15 mg DON and 0.0035 mg ZON/kg diet) or a diet containing 15% of Fusarium toxin contaminated triticale (MYCO, 4.42 mg DON and 0.048 mg ZON/kg diet) in the period of day 35 and 70 of gestation. The indirect effect of feed intake was separated from the direct effects of the Fusarium toxins by the restricted feeding regimen where all sows were fed the same amount of feed (2000 g/d) over the whole study. At the end of experiment, fetuses were delivered by Caesarian section and samples of serum, bile, urine, liver, kidney and spleen of euthanatized sows and fetuses were taken to analyze the concentrations of DON, ZON and their metabolites. Feeding the Fusarium toxin contaminated diet to pregnant sows caused neither adverse effects on performance, organ weights and maintenance of pregnancy of sows nor on fetus weight and length. Furthermore, no teratogenic or embryolethal effects could be observed in the MYCO group. Hematological and clinical-chemical parameters of sows and fetuses were not affected by feeding, with the exception of significantly lower GLDH (glutamate dehydrogenase) serum activities in MYCO sows. The carry over of DON and ZON from the diet to the sow or fetus tissues was calculated by the diet ratio (sum of concentrations of all metabolites in the physiological specimen divided by the dietary toxin concentration), while the fetus ratio was evaluated by the sum of concentrations of all metabolites in the physiological specimen of the fetus divided by that of the sows. DON and deepoxy-DON were found in urine, bile, serum, liver, kidney and spleen of sows of the MYCO group, but not in the bile of fetuses (spleen not analyzed). ZON and its metabolite alpha-zearalenol (alpha-ZOL) were detected in urine and bile of sows, while all specimens of fetuses as well as serum and liver of sows were negative for ZON metabolites. The maximum diet ratios for urine and bile in sows of the MYCO group were 0.84 and 0.05 for DON metabolites and 1.2 and 3.8 for ZON metabolites, underscoring the differences in metabolism and excretion of both toxins. The maximum diet ratio of DON and deepoxy-DON into liver, kidney and spleen of MYCO sows were 0.003, 0.007 and 0.003, respectively. The maximum fetus ratio of DON and deepoxy-DON into urine, bile, serum, liver and kidney of fetuses were 0.006, 0, 0.5, 0.88, and 0.33, while the maximum placental ratio (sum of toxin concentrations in the physiological specimen of the fetus divided by the toxin serum concentration of the sow) were 0.64, 0, 0.50, 0.70 and 0.52, respectively. Therefore, it can be concluded that the developing fetus is exposed to DON between the gestation days 35 and 70 when the sows are fed a Fusarium toxin contaminated diet. ZON concentration in the MYCO diet was too low to get reliable results for fetus or placental ratios.

On the transfer of the Fusarium toxins deoxynivalenol (DON) and zearalenone (ZON) from the sow to the full-term piglet during the last third of gestation.

Pregnant sows were fed either a control diet (CON, n=8, 0.21 mg DON and 0.004 mg ZON/kg diet) or a diet containing 40% of a Fusarium toxin contaminated wheat (MYCO, n=7, 9.57 mg DON and 0.358 mg ZON/kg diet) from day 75 to 110 of gestation. Piglets were delivered by Caesarean section at the end. Spleen weights of piglets from the MYCO group were significantly lower. Hemoglobin concentration and hematocrit were also significantly decreased in these piglets, although this effect was more obvious in female than in male piglets. The transfer of DON and ZON was evaluated by the diet ratio (sum of concentrations of all metabolites in the physiological specimen divided by the dietary toxin concentration) and the piglet ratio (sum of concentrations of all metabolites in the physiological specimen of the piglet divided by that of the sows). The diet ratio for the liver (sows only) amounted to 0.001 (DON+de-epoxy-DON) and 0.016 (ZON and metabolites). The diet ratios of DON in bile reached up to 0.041 and 0.003 for sows and piglets, respectively, and those for ZON up to 2.896 and 0.128. The piglet ratios in bile varied up to 0.309 and 0.518 for DON and ZON, respectively, whereas nearly similar DON concentrations were found in serum of piglets and sows (median piglet ratio of 0.750). The results of the study suggest that the developing fetus is exposed to DON, ZON and their metabolites when the sows are fed a Fusarium toxin contaminated diet.

On the interactions between Fusarium toxin-contaminated wheat and non-starch-polysaccharide hydrolysing enzymes in turkey diets on performance, health and carry-over of deoxynivalenol and zearalenone.

1. Diets with increasing proportions of Fusarium toxin-contaminated wheat (0, 170, 340 and 510 g CW/kg) were fed to male turkeys (BUT Big 6) from d 21 to d 56 of age. Each diet was tested with or without a non-starch-polysaccharide (NSP) hydrolysing enzyme preparation. Dietary deoxynivalenol (DON) and zearalenone (ZON) concentrations were successively increased up to approximately 5.4 and 0.04 mg/kg, respectively. 2. Weight gain decreased slightly with increasing proportions of CW, by 1.6, 0.7 and 3.6%, whereas other performance parameters remained unaffected. NSP enzyme supplements to the diets had no influence. 3. The weight of the emptied jejunum plus ileum, relative to live weight, decreased in a dose-related fashion whereby the NSP enzyme exerted an additional weight-decreasing effect. A similar weight-decreasing NSP enzyme effect was noted for heart weights. Activity of glutamate dehydrogenase in serum was significantly increased in groups fed the diets with the highest CW proportion, whereas gamma-glutamyl-transferase remained unaltered. 4. Viscosity in the small intestine was significantly reduced by supplementing the diets with the NSP enzyme. This effect successively decreased with increasing proportions of the CW. 5. Concentrations of DON and of its de-epoxidised metabolite de-epoxy-DON in plasma, liver and breast meat were lower than the detection limits of 2 ng/ml (plasma) and 4 ng/g, respectively, of the applied HPLC method. DON concentration in bile reached up to 13 to 23 ng/ml whereas de-epoxy-DON concentration was lower than 4 ng/ml. 6. ZON or its metabolites were not detectable in plasma, liver or breast meat (detection limits of the HPLC method were 1, 0.5 and 5 ng/g for ZON, alpha-zearalenol (ZOL) and beta-ZOL, respectively). Concentrations of ZON and alpha-ZOL in bile increased with dietary ZON concentration. The mean proportions of ZON, alpha-ZOL and beta-ZOL of the sum of all three metabolites were 19, 77 and 4%, respectively.

Effects of different levels of ergot in concentrate on the health and performance of male calves.

A number of studies dealing with the effects of ergot and ergot alkaloids on the health and performance of poultry and pigs were reported in the past, but only a few studies and field reports are available for ruminants. Therefore, a dose-response study was carried out with calves since young animals are considered to be especially sensitive to ergot.A total of 35 male Holstein calves were randomly assigned to three feeding groups after one month of feeding milk replacer. The mean initial live weight of the calves was 49.4±5.7 kg. One control group was fed an ergot-free concentrate (n=12), one group an ergot proportion of 1000 mg/kg in the concentrate (n=ll), and another group was fed a concentrate containing 5000 mg/kg ergot (n=12). Hay, grass silage and water were available forad libitum consumption, whereas the daily concentrate portion was restricted to 2 kg. Live weight, health parameters and feed intake were monitored over the experimental period of 84 days. In addition, blood samples were taken from theVena jugularis at the beginning and at the end of the experiment and analysed for ergot alkaloids and liver parameters.Total dry matter intake, live weight gain and feed-to-gain ratio were not significantly influenced by increasing ergot proportions when the whole experimental period was considered, although there was a trend for an ergot-related decrease in concentrate intake during the first 6 weeks of the experiment. After this period of time, it seemed that calves got used to the presence of ergot in the concentrate and were able to adjust their intake to the level of the control group. Moreover, health and liver parameters, such as total bilirubin, aspartate aminotransferase, glutamate dehydrogenase, gamma-glutamyl transpeptidase and creatine kinase in the serum were not significantly influenced by dietary treatments. Concentrations of the individual ergot alkaloids in serum were lower than the detection limits of the applied HPLC-method.In conclusion, it can be assumed that an ergot contamination of the concentrate up to 5000 mg/kg resulted in a transient depression of concentrate intake by the calves. However, no significant effects on health and performance could be detected when the entire test period of 84 days was considered.

On the effects of Fusarium toxin contaminated wheat and wheat chaff on nutrient utilisation and turnover of deoxynivalenol and zearalenone in vitro (Rusitec).

The objective of the present study was to investigate the effects of Fusarium toxin contaminated wheat and wheat chaff (mycotoxin diet) on nutrient degradability and the metabolism of the mycotoxins deoxynivalenol (DON) and zearalenone (ZON) using the rumen simulations technique (Rusitec). A 6 day application period with control wheat and wheat chaff (control diet) was followed by an 8 day sampling phase. During this time three fermenters received the mycotoxin diet (64.9 mg DON/kg dry matter (DM) and 500 microg ZON/kg DM) and the remaining fermenters served as the controls (1.0mg DON/kg DM and 6 microg ZON/kg DM). Feed residues of the bags and samples of the effluent liquids were pooled per fermenter during the last 8 days of the experiment. Additionally, effluents of the mycotoxin fermenters were taken 6, 12 and 24h after the morning feeding on the first day of the sampling phase. The degradation of organic matter (OM; P<0.05), neutral detergent fibre (NDF; P<0.01) and protein (P<0.001) were increased by administration the Fusarium contaminated diet which was accompanied by an increased ammonia concentration (P<0.01) and increased butyrate (P<0.01), isobutyrate (P<0.01) and isovalerate (P<0.05) values of the mycotoxin effluents in relation to the controls. High proportions of ingested DON of 90% (85-93%) and ingested ZON of 93% (80-104%) were recovered at the pooled feed residues and effluents in form of DON and de-epoxy DON, and ZON and alpha-ZOL after administering the Fusarium toxin contaminated feed. While adsorption of DON as DON and de-epoxy DON in the feed particles was only minor (5%), a higher amount of 38% of ingested ZON was recovered as ZON and alpha-ZOL at the feed residues. The total recovery of DON plus de-epoxy DON in effluents as a percentage of DON intake reached 8%, 9% and 22% of ingested DON at 6, 12 and 24h after application of the contaminated diet the first time, whereby the recovery of de-epoxy DON as percentage of DON intake was only 5% at 24h. Concentrations of ZON and metabolites were lower than detection limits in the time dependent effluent samples.

On the effects of Fusarium toxin-contaminated wheat and the feed intake level on the metabolism and carry over of zearalenone in dairy cows.

The aim was to investigate the effect of feeding Fusarium toxin-contaminated wheat to dairy cows on the metabolism and carry over of zearalenone (ZON) and its metabolites at different feed intakes. Fourteen dairy cows equipped with rumen and duodenal fistulae were used. The experiment consisted of a control period in which the uncontaminated wheat was fed and a mycotoxin period in which the Fusarium toxin-contaminated wheat (8.21 mg deoxynivalenol (DON) and 91 microg ZON kg(-1) dry matter (DM)) was replaced by the control wheat (0.25 mg DON kg(-1) and 51 microg ZON kg(-1) DM). The wheat portion of the concentrate fed daily amounted to 55% on a DM basis. The ration was completed with maize and grass silage (50:50), whereby the maize silage contained 62 microg ZON kg(-1) DM. Feed intakes were adjusted to the current performance of the individual cows. The ZON metabolites alpha-zearalenol (alpha-ZOL) and beta-zearalenol (beta-ZOL) were recovered at the duodenum beside the parent toxin ZON. The recovery of ingested ZON as ZON plus alpha-ZOL plus beta-ZOL at the duodenum ranged between 19 and 247%. The portion of ZON (ranging from 29 to 99%) of the ZON plus alpha-ZOL plus beta-ZOL flow at the duodenum increased significantly with increasing ZON feed intake, whereas the portion of beta-ZOL (up to 57%) decreased significantly. In contrast, portions of ZON in faeces (32-100%), alpha-ZOL (up to 39%) and beta-ZOL (up to 43%) of ZON plus alpha-ZOL plus beta-ZOL were independent of ZON intake. It seems that a lower retention time of the feed and the toxins in the rumen as an effect of the increased feed intake may limit the ruminal metabolization of ZON. The relatively steady recovery of ingested ZON as ZON, alpha-ZOL and beta-ZOL in faeces at the different levels of ZON intake would suggest a further reduction of ZON by intestinal microorganisms. Furthermore, ZON and its metabolites in the milk were lower than the detection limits at daily ZON and DM intakes between 75 and 1125 microg and 5.6 and 20.5 kg day(-1), respectively, and milk yields (fat corrected milk, FCM) between 10 and 42 kg day(-1).

Effects of Fusarium toxin-contaminated wheat grain on nutrient turnover, microbial protein synthesis and metabolism of deoxynivalenol and zearalenone in the rumen of dairy cows.

The aim of the present study was to examine the effects of feeding Fusarium toxin-contaminated wheat to dairy cows on nutrient utilization in the rumen and on duodenal flow of deoxynivalenol (DON), zearalenone (ZON) and their metabolites. Six dairy cows fitted with a large rumen cannula and a simple T-shaped cannula at the proximal duodenum was used in two experiments. The experiments included a control period in which the uncontaminated control wheat was fed and a period in which the control wheat was replaced by the Fusarium toxin-contaminated wheat (8.05 and 7.15 mg DON/kg and 0.26 and 0.1 mg ZON/kg in Expts 1 and 2 respectively). The wheat portion of the daily ration amounted to 50% on a dry matter (DM) basis and rations were completed with hay or grass silage. Five of the six cows were non-lactating and the total daily DM-intake ranged between 4 and 12 kg. The pH-values and the concentration of volatile fatty acids in ruminal fluid were not significantly influenced by feeding the contaminated wheat. In contrast, the postprandial ammonia concentration was consistently higher when the mycotoxin-contaminated wheat was fed. Moreover, the flow of microbial protein and utilizable protein at the duodenum were reduced at the same time. The concentrations of DON and ZON and of their metabolites in freeze-dried duodenal digesta were either not detectable or negligible during the control periods whereas distinct concentrations were measured during the periods where the contaminated wheat was fed. DON was nearly completely metabolized to de-epoxy-DON and the flow at the duodenum ranged between 4% and 28% of DON-intake. The ZON metabolites alpha-zearalenol (ZOL) and beta-ZOL were recovered at the duodenum beside the parent toxin ZON. Their recovery as a percentage of ZON-intake ranged between 43% and 132%. In conclusion, feeding of Fusarium toxin-contaminated wheat altered the ruminal protein utilization. The question of whether this effect was a result of the mycotoxin being present in the rumen or of Fusarium growth-related structural (cell wall) changes of the wheat grain needs to be clarified. The low recovery of DON at the duodenum would indicate either a nearly complete degradation of the molecule in the rumen or an absorption by the mucosa of the rumen, whereas the higher ZON recovery would suggest a lower degradation of the parent toxin in the rumen and/or recovery of some bile-originating entero-hepatic cycling ZON/metabolites.

The efficacy of a modified aluminosilicate as a detoxifying agent in Fusarium toxin contaminated maize containing diets for piglets.

Two feeding experiments with female weaned piglets were carried out applying a complete two by two factorial design to investigate the effects of the dietary inclusion of 500 g/kg Fusarium toxin contaminated maize (8.6 mg/kg deoxynivalenol (DON); 1.2 mg/kg zearalenone (ZON)) and of 4 g/kg aluminosilicate (AS) as a detoxifying agent. The resulting four diets were fed ad libitum to a total of 80 piglets (20 piglets per group, allotted to a total of 20 pens) covering a live weight range of 10.5 +/- 1.3 to 27.5 +/- 4.4 kg in experiment 1, and to a total of 48 piglets (12 piglets per group, allotted to 12 pens) covering a live weight range of 9.7 +/- 1.8 to 21.4 +/- 4.8 kg in experiment 2. The animals of experiment 1 were slaughtered on days 34-36 of feeding the experimental diets. The mycotoxin analyses revealed that the control maize also contained considerable concentrations of Fusarium toxins, but the differences in DON and ZON concentrations between control and contaminated diets were sufficiently high to demonstrate both dose-related toxin effects. Voluntary feed intake and live weight gain of the animals were significantly reduced by the inclusion of Fusarium toxin contaminated maize into the diets in both experiments, while a significantly decreased feed to gain ratio was found in experiment 1. Furthermore, the relative weight of the uterus, stomach and heart of the animals fed the contaminated maize containing diets were significantly increased. Serum albumin concentrations and the activity of GLDH were significantly reduced by the inclusion of the contaminated maize. The addition of AS to the Fusarium toxin contaminated diets did not prevent or alleviate any of the mentioned effects. Moreover, the feed intake tended to be decreased by this supplementation in both experiments, while a significantly decreased feed to gain ratio was indicated for this factor in experiment one as well. The serum concentration of albumin and the activities of ASAT and gammaGT were significantly increased if AS was present in the diets while serum concentration of cholesterol and alpha-tocopherol were decreased significantly or in tendency, respectively. The concentrations of retinol and retinyl esters in liver and serum were not altered by the treatments. The analysed concentrations of zearalenone (ZON) and its metabolites in the bile fluid clearly indicated the differences in dietary ZON concentrations and showed that AS was ineffective in preventing the absorption of the toxin from the gastrointestinal tract. Also, serum concentrations of DON reflected the DON intake prior to sampling. However, there were no differences between groups fed diets with or without AS which also suggests the inefficacy of the tested AS in preventing the DON absorption. The present investigations failed to demonstrate a detoxifying capacity of the tested additive and emphasize the general necessity for a critical verification of detoxifying agents in vivo.

Kinetics and metabolism of zearalenone in young female pigs.

The fate of a single bolus of the Fusarium mycotoxin zearalenone (ZON) given intravenously to pigs was followed up. Pigs were equipped with duodenal re-entrant cannulas, post-valvular T-shape cannulas and with a urinary bladder balloon catheter. The animals were divided into three groups. Pigs of the control group were injected with ZON (Co), and pigs of the second group were also injected with ZON but their duodenal digesta was quantitatively exchanged for 12 h with corresponding pigs of the third group, not injected with ZON. Therefore, the second group had a disrupted entero-hepatic cycling of ZON (DEHC) and the third one had an induced entero-hepatic cycling of ZON (IEHC). The kinetic profile of ZON and its metabolites in plasma and their flow with urine, duodenal and ileal digesta and with faeces was examined over the next 72 h after the bolus was given. Eleven days later, pigs were slaughtered for collection of bile, urine and liver to analyse ZON residues. In all specimens examined, alpha-zearalenol (ZOL) was detected as the only metabolite of ZON. Kinetic evaluation of the plasma data revealed that the terminal elimination half-life of ZON was reduced from 2.63 h in pigs of Co-group to 1.1 h when EHC of ZON was disrupted for 12 h (DEHC-group). The maximum ZON concentration in plasma of pigs with the IEHC was found at 2.73 h after the bolus was given to their counterparts. The percentage of the alpha-ZOL- and ZON-area under the curves (AUC) estimated for the IEHC-group amounted to approximately 18% of the corresponding AUC of the Co-group which would suggest that a substantial proportion of both substances are re-cycled via entero-hepatic re-circulation. Cumulative recovery of ZON and alpha-ZOL, expressed as percentage of the ZON-bolus was characterized by a saturation kinetics in urine and duodenal digesta, and after 72 h, the respective values for Co-, DEH-, and IEHC-groups were 70%, 55% and 12%; and 35%, 22% and 11%. Faecal excretion started to increase steeply after 48 h and still continued to increase after 72 h when the cumulative excretion was 6%, 3% and 2% for Co-, DEHC- and IEHC-groups respectively. Fourteen days after the bolus injection, ZON and alpha-ZOL concentrations in bile, liver and urine were lower than the detection limits of the applied method. The results would suggest that within this period of time a massive single bolus of ZON is nearly completely eliminated from the body.

[Effect of a hydrothermal treatment on ergot alkaloid content in ergot contaminated rye]. / Zum Einfluss einer hydrothermischen Behandlung auf den Ergotalkaloidgehalt von mutterkornbelastetem Roggen.

Hydrothermal treatments are primarily used to increase the digestibility of nutrients and therefore to improve the feeding value of feedstuffs mainly for non-ruminants. Other positive side effects may occur, e.g. a decrease in toxicity of feed contaminated with mycotoxins. To study such effects, 4 batches of rye containing different percentages (0.8, 4.2, 8.3 and 25%) of ergot (Claviceps purpurea) were expanded and ergot alkaloid contents were analysed. After pre-conditioning of each batch by steam exposure for approx. 2 min, at 95 °C and 17% moisture, the material was expanded for approx. 5 sec. at 120 °C, 18% moisture, 40 bar mechanical pressure and 20 kWh/t mechanical energy input. Samples were collected before and after pre-conditioning and after expanding. Ergot alkaloids were analysed by HPLC. Analysis includedErgometrine, Ergotamine, Ergocornine, Ergocryptine, Ergocristine, Ergosine and their respective-inine isomers, the sum of these 12 ergot alkaloids was referred to as the total alkaloid content.On average, the hydrothermal treatment (pre-conditioning and expanding) caused a decrease of the total ergot alkaloid content of approx. 10%. Except for the batch containing 0.8% ergot, the efficiency of the hydrothermal treatment decreased with increasing ergot concentration in the batches. In general, the hydrothermal treatment changed the proportions of the ergot alkaloid isomers since the percentages of the-inine isomers of the total ergot alkaloid contents were increased with reduced-ine percentages. Whether this alteration is of toxicological relevance should be evaluated in animal experiments.

On the effects ofFusarium-contaminated wheat and the feed intake level on ruminal fermentation and toxin-turnover of cows.

The aim of the study was to examine the effects of dry matter intake level and the feeding ofFusarium-contaminated wheat on the toxin-turnover and ruminal fermentation of dairy cows. Fourteen dairy cows equipped with ruminal and duodenal cannulae were used. All animals were fed the same diet, only the daily feed amounts were adjusted to the current performance stage of the cow. On a dry matter basis, the diet consisted of 60% concentrate including 55% wheat (Fusarium-contaminated wheat [Mycotoxin period] or control wheat [Control period]). Each cow was fed with both the contaminated and the control wheat. TheFusarium-contamination of the wheat significantly decreased the flow of undegraded protein at the duodenum with increased intakes of organic matter. The duodenal flow of microbial protein and the activities of aspartate aminotransferase (ASAT), glutamate dehydrogenase (GLDH) and gamma glutamyl transferase (γ-GT) in the serum were not affected by dietary treatment, but increased with feed intake. The duodenal flow of deoxynivalenol (DON) and de-epoxy DON related to DON intake ranged between 12 and 77% when theFusarium-contaminated wheat was fed. DON was almost completely metabolized to de-epoxy DON independent of the feed intake level. The zearalenone (ZON) flow at the duodenum increased moderately with increasing ZON/feed intake.

Effects of graded levels of Fusarium-toxin-contaminated wheat in Pekin duck diets on performance, health and metabolism of deoxynivalenol and zearalenone.

1. Diets with increasing proportions of Fusarium-toxin-contaminated wheat were fed to Pekin ducks for 49 d in order to titrate the lowest effect level. Dietary deoxynivalenol (DON) and zearalenone (ZON) concentrations were successively increased up to 6 to 7 mg/kg and 0.05 to 0.06 mg/kg, respectively. 2. Feed intake, live weight gain and feed to gain ratio were not influenced by dietary treatment. 3. Gross macroscopic inspection of the upper digestive tract did not reveal any signs of irritation, inflammation or other pathological changes. The weight of the bursa of Fabricius, relative to live weight, decreased in a dose-related fashion. Activities of glutamate dehydrogenase and gamma-glutamyl-transferase in serum were either unaffected or inconsistently affected by dietary treatments. 4. Concentrations of DON and of its de-epoxydised metabolite in plasma and bile were lower than the detection limits of 6 and 16 ng/ml, respectively, of the applied high performance liquid chromatography (HPLC) method. 5. ZON or its metabolites were not detectable in plasma and livers (detection limits of the HPLC method were 1, 0.5 and 5 ng/g for ZON, alpha-zearalenol (alpha-ZOL) and beta-zearalenol (beta-ZOL), respectively). Concentrations of ZON, alpha-ZOL and beta-ZOL in bile increased linearly with dietary ZON concentration. The mean proportions of ZON, alpha-ZOL and beta-ZOL of the sum of all three metabolites were 80, 16 and 4%, respectively. 6. Taken together, it can be concluded that dietary DON and ZON concentrations up to 6 and 0.06 mg/kg, respectively, did not adversely affect performance and health of growing Pekin ducks.

Dose-response feeding study of chlorinated paraffins in broiler chickens: effects on growth rate and tissue distribution.

Even with the highest additions of 100mg kg(-1) short-chain (C10-C13) chlorinated paraffins (CP) to feed, the health of broilers was not adversely affected during a 31-day feeding experiment. In addition, 1 and 3 weeks after the experiment started, growth rate and feed consumption of the young animals were not impaired. No significant influence on mortality, organ weight relative to live weight or performance (weight gain, feed consumption) was noted. The CP concentrations in abdominal fat, meat, liver and kidneys were related linearly to the CP concentration of the feed. The highest contents were analysed in fat and the faeces, and the lowest concentrations were found in blood, meat and bile fluid. Less than 5% of the CP amount consumed was incorporated into the body, without taking the head, gut, feet and feathers into account.

Effects of graded levels of Fusarium toxin contaminated maize in diets for female weaned piglets.

A dose response study was carried out with piglets to examine the effects of increasing amounts of Fusarium toxins in the diet on performance, clinical serum characteristics, organ weights and residues of zearalenone (ZON) and deoxynivalenol (DON) and their metabolites in body fluids and tissues. For this purpose, Fusarium toxin contaminated maize (1.2 mg ZON and 8.6 mg DON per kg maize) was incorporated into a maize based diet for piglets at 0, 6, 12.5, 25 and 50% at the expense of control maize. The experimental diets were tested on 100 female piglets allotted to 20 boxes (five animals per box) covering a body weight range of 12.4 +/- 2.2 kg to 32.5 +/- 5.6 kg. Voluntary feed intake and, consequently, body weight gain of the animals receiving the highest proportion of Fusarium toxin contaminated maize were significantly decreased while the feed conversion ratio was not affected by the treatment. The mean weight of the uterus related to the body weight of the animals of the same group was increased by almost 100% as compared to the control. For this group, significantly decreased values of total serum protein were determined, while the serum activity of the liver enzyme glutamate dehydrogenase and the serum concentration of the follicle stimulating hormone were decreased for all treatment groups receiving 6% contaminated maize or more in the diet. Serum concentrations of immuneglobulins were not consistently altered by the treatment. Corresponding to the dietary exposure, increasing concentrations of ZON and alpha-zearalenol were detected in the bile fluid, liver and in pooled urine samples. The metabolite beta-zearalenol was detected only in bile fluid. The total concentration of ZON plus its metabolites in bile fluid correlated well with the diet contamination (r = 0.844). DON was found in serum, bile fluid and pooled urine samples while de-epoxy-DON was detected only in urine. The serum concentration of DON correlated well with the respective toxin intake 3-4 h prior to slaughtering (r = 0.957). For all mentioned analyses of residues it has to be noted that toxin residues were detectable even if negligible concentrations were present in the diet.

Effects of graded levels of Fusarium toxin-contaminated wheat and of a detoxifying agent in broiler diets on performance, nutrient digestibility and blood chemical parameters.

1. A growth experiment was carried out with male broilers from d 1 to d 35 of age in order to evaluate the effects of the addition of a detoxifying agent (Mycofix Plus, Biomin GmbH, Herzogenburg, Austria) at different dietary proportions of wheat (0, 16.5, 33, 49.5 and 66%) contaminated with Fusarium mycotoxins (21.2 mg of deoxynivalenol and 406 microg of zearalenone, ZON, per kg of wheat) on growth performance, nutrient and zearalenone balance and clinical-chemical parameters. 2. An increase in dietary mycotoxin concentration resulted in a linearly related decrease in feed intake, a slight decrease in weight gain and an improvement in feed to gain ratio. 3. Apparent protein digestibility and net protein utilisation were higher in diets containing exclusively Fusarium toxin-contaminated wheat than control diets. 4. The proportions of beta-zearalenol, alpha-zearalenol and ZON of total ZON metabolites in excreta of broilers fed on the diets containing the Fusarium toxin-contaminated wheat were approximately 3, 21 and 76%. 5. Serum antibody titres to Newcastle disease virus decreased in a linear fashion with increasing mycotoxin concentration in the diets, whereas other clinical-chemical serum parameters (liver cell and muscle cell necrosis indicating enzymes, haemoglobin, haematocrit, magnesium, inorganic phosphate) were not influenced by increasing Fusarium toxin concentrations. 6. Supplementation of the diets with Mycofix Plus decreased performance in a manner independent of mycotoxin concentration. Moreover, some clinical-chemical serum parameters were significantly altered due to Mycofix Plus but also independently of the dietary mycotoxin concentration.

Fusarium toxin residues in physiological samples of piglets.

Physiological samples of 100 piglets fed diets containing 0.01, 0.06, 0.15, 0.22 and 0.42 mg ZON and 0.2, 0.8, 1.0, 1.9 and 3.9 mg DON per kg over a period of 35±1.5 days were investigated for concentrations of deoxynivalenol (DON) and zearalenone (ZON) and their metabolites.DON was detected in serum, bile and urine in increasing concentrations corresponding to the diet contamination. The metabolite de-epoxy-DON was detected only in urine. The DON contamination of the diet was closely reflected by the serum concentrations of the piglets.ZON and its metabolite α-zearalenol were detected in bile fluid, liver and urine, while ß-zearalenol was only detected in bile fluid. In serum neither ZON nor its metabolites were found. The total concentration of ZON plus its metabolites in the bile fluid corresponded well with the dietary contamination.For all analyses it has to be noted that toxin residues were detectable even in individual samples of piglets fed the control diet containing 0.01 mg ZON/kg and 0.2 mg DON/kg.

Effects of Fusarium toxin contaminated wheat and of a detoxifying agent on performance of growing bulls, on nutrient digestibility in wethers and on the carry over of zearalenone.

Experiments were carried out to examine the effects of a Fusarium contaminated wheat (10 mg deoxynivalenol and 0.76 mg zearalenone, ZON, per kg dry matter) and of a detoxifying agent (Mycofix Plus, Biomin GmbH, Herzogenburg, Austria) on the growing performance of bulls, carry-over of ZON and its metabolites into body fluids and tissues, and on nutrient digestibility in wethers. The experiments were designed according to a complete two by two factorial approach which meant that both the uncontaminated control wheat and the Fusarium toxin contaminated wheat were tested both in the absence and presence of Mycofix Plus. The growing experiment with bulls (n = 14 per treatment) covered the live weight range between 244 kg and 460 kg. The respective wheat batches were included in the concentrate portion at 65%. Concentrates were fed according to plan whereas maize silage was offered for ad libitum consumption. Daily dry matter intake and live weight gain [kg per animal and day] were 7.40, 7.52, 7.51 and 7.49 and 1.367, 1.296, 1.380 and 1.307 for bulls fed the unsupplemented control wheat, the supplemented control wheat, the unsupplemented and Fusarium toxin contaminated wheat and the supplemented Fusarium toxin contaminated wheat, respectively. ZON and its metabolites were not detected in edible tissues. The most striking effects of feeding the Fusarium toxin contaminated wheat on carcass characteristics were a reduced dressing percentage, an increased weight of the emptied gastro-intestinal tract and a reduced weight of the testicles. No effect of the detoxifying agent was seen for these parameters whereas heart weight increased independently of Fusarium toxin contamination of the concentrates. Nutrient digestibility of the two wheat batches, unsupplemented or supplemented with Mycofix Plus was evaluated according to the difference method using wethers. Presence of Fusarium toxins in wheat did not influence its feeding value. The effects of the addition of the detoxifying agent were mycotoxin unspecific and resulted in an increase in apparent digestibility of crude protein and a decrease in crude fiber digestibility. It is concluded that feeding of Fusarium toxin contaminated wheat did not adversely affect performance of growing bulls (approximately 2.2 mg DON and 0.1 mg ZON per kg complete ration at a reference dry matter content of 88%) or nutrient digestibility in wethers. The effects of the detoxifying agent Mycofix Plus on growing performance and on nutrient digestibility were rather Fusarium toxin unspecific. The slightly negative effects on growing performance needs to be examined further.

Effect of addition of a detoxifying agent to laying hen diets containing uncontaminated or Fusarium toxin-contaminated maize on performance of hens and on carryover of zearalenone.

16-wk experiment with laying hens was carried out to examine the effects of feeding of mycotoxin-contaminated maize (CM) on performance, nutrient digestibility, weight of organs, serum chemical parameters, and antibody titers to Newcastle disease virus (NDV) in serum. Also tested were fimbrien antigen K88 in egg yolk and zearalenone (ZON) residues in eggs and tissues. The Fusarium-toxin-contaminated maize contained 17,630 microg deoxynivalenol and 1,580 microg ZON/kg. Moreover, Mycofix Plus (MP), a so-called detoxifying agent, was added to both the uncontaminated control (UCM) and to the CM diet (70% dietary maize inclusion). Each of the four resulting diets (UCM, UCM-MP, CM, CM-MP) was tested on 25 laying hybrids (Lohmann Brown). Feeding of the CM diets significantly depressed feed intake compared to the control groups by approximately 5%. This was mainly due to the effects observed at the beginning of the experiment. Daily egg mass production/hen was 56.6, 58.4, 53.9, and 55.2 g in groups UCM, UCM-MP, CM and CM-MP, respectively. Nutrient digestibility and metabolizability of gross energy were slightly depressed by feeding the CM diets and improved by MP addition. Feeding of the CM diets resulted in a significant decrease in serum titers to NDV and to an increase in yolk titers to antigen K88. No residues of ZON or of its metabolites were found in yolk, albumen, abdominal fat, breast meat, follicles greater than 1 cm in diameter, ovaries including follicles smaller than 1 cm in diameter, magnum, and serum. ZON and alpha-zearalenol (alpha-ZOL) were detected in livers of hens fed the CM diets at mean concentrations of 2.1 and 3.7 microg/kg, respectively. It was concluded that feeding maize which was highly contaminated with Fusarium mycotoxins adversely influenced performance of hens and modulated immune response. At the given level of zearalenone and at the indicated detection limits, no residues of ZON and its metabolites were found in eggs. The effects of the tested detoxifying agent were quite mycotoxin-independent.

Effects ofFusarium-toxincontaminated wheat in ruminant nutrition.

An experiment was carried out to examine the effects of aFusarium-contaminated wheat grain as a component of the concentrate portion (10 mg deoxynivalenol and 0.76 mg zearalenone, ZON, per kg dry matter) on performance of growing bulls, and on carry over of ZON into tissues and body fluids. In a second study, rumen physiological parameters were investigated in wethers equipped with rumen fistulae. Moreover, the influences of a detoxifying agent (Mycofix®, MP, Biomin GmbH, Herzogenburg, Austria) were considered as an additional experimental factor beside the contamination of the wheat (uncontaminated control wheat,Fusarium-toxincontaminated wheat).The fattening experiment with bulls (n=14 per treatment) covered the live weight range between 244 kg and 460 kg. Daily dry matter intake and live weight gain (kg per animal and day) were 7.40, 7.52, 7.51 and 7.49 and 1.367, 1.296, 1.380 and 1.307 for bulls fed the unsupplemented control wheat, the supplemented control wheat, the unsupplemented andFusarium toxin contaminated wheat and the supplementedFusarium toxin contaminated wheat, respectively. Concentration of ZON and its metabolites in edible tissues were lower than the detection limits of the applied HPLC-method.The results of the rumen physiological investigations revealed that the molar ratios of short chained volatile fatty acids and ammonia concentration in rumen fluid remained unchanged in response to dietary treatments whereas the addition of MP to the diets buffered the postprandial decrease in rumen pH.