No abstract

The aim of the present experiment was to investigate the effects of feeding grains naturally contaminated with Fusarium mycotoxins on morphometric indices of jejunum and to follow the passage of deoxynivalenol (DON) through subsequent segments of the digestive tract of broilers. A total of 45 1-d-old broiler chickens (Ross 308 males) were randomly allotted to three dietary treatments (15 birds/treatment): (1) control diet; (2) diet contaminated with 1 mg DON/kg feed; (3) diet contaminated with 5 mg DON/kg feed for five weeks. None of the zootechnical traits (body weight, body weight gain, feed intake, and feed conversion) responded to increased DON levels in the diet. However, DON at both dietary levels (1 mg and 5 mg DON/kg feed) significantly altered the small intestinal morphology. In the jejunum, the villi were significantly (P < 0.01) shorter in both DON treated groups compared with the controls. Furthermore, the dietary inclusion of DON decreased (P < 0.05) the villus surface area in both DON treated groups. The absolute or relative organ weights (liver, heart, proventriculus, gizzard, small intestine, spleen, pancreas, colon, cecum, bursa of Fabricius and thymus) were not altered (P > 0.05) in broilers fed the diet containing DON compared with controls. DON and de-epoxy-DON (DOM-1) were analyzed in serum, bile, liver, feces and digesta from consecutive segments of the digestive tract (gizzard, cecum, and rectum). Concentrations of DON and its metabolite DOM-1 in serum, bile, and liver were lower than the detection limits of the applied liquid chromatography coupled with mass spectrometry (LC-MS/MS) method. Only about 10 to 12% and 6% of the ingested DON was recovered in gizzard and feces, irrespective of the dietary DON-concentration. However, the DON recovery in the cecum as percentage of DON-intake varied between 18 to 22% and was not influenced by dietary DON-concentration. Interestingly, in the present trial, DOM-1 did not appear in the large intestine and in feces. The results indicate that deepoxydation in the present study hardly occurred in the distal segments of the digestive tract, assuming that the complete de-epoxydation occurs in the proximal small intestine where the majority of the parent toxin is absorbed. In conclusion, diets with DON contamination below levels that induce a negative impact on performance could alter small intestinal morphology in broilers. Additionally, the results confirm that the majority of the ingested DON quickly disappears through the gastrointestinal tract.

Recent data suggest that Fusarium trichothecenes may reduce broiler performance at levels previously thought not to affect this variable in chickens. In the present study, we investigated the effects of deoxynivalenol (DON), a type-B trichothecene, on broilers. Male broilers at 7 d of age were fed either a basal diet (0.265 ± 0.048 mg of DON; 0.013 ± 0.001 mg of zearalenone/kg), a low DON diet (1.68 mg of DON/kg; 0.145 ± 0.007 mg of zearalenone/kg), or a high DON diet (12.209 ± 1.149 mg of DON/kg; 1.094 ± 0.244 mg of zearalenone/kg). Increasing levels of DON decreased the weekly weight gain linearly (P ≤ 0.041) during the first 3 wk of exposure; there were no significant differences in the weight gain of the birds after wk 3. With increasing levels of DON, the titers against Newcastle disease virus increased linearly during wk 2 (P = 0.022) and wk 4 (P = 0.033) of exposure, whereas the titers against infectious bronchitis virus decreased linearly (P = 0.006) during wk 5 of exposure. The serum protein concentration increased linearly (P = 0.017) during wk 2 and quadratically (P = 0.002) during wk 4 of exposure. Under these experimental conditions, the performance and vaccine response of the broilers were modulated to varying degrees at concentrations of DON that are currently permitted (up to 5 mg/kg of diet) in many countries. Further studies are therefore required to clarify the implications of these results on the welfare of chickens.

We performed a 4-year survey (2006-2009, 1255 samples) of fungal secondary metabolites in feed material (cereal and corn grains) and feedstuffs (silages, mixed feeds). Five major mycotoxin groups were studied, including aflatoxins (AF), ochratoxin A (OTA), trichothecenes [deoxynivalenol (DON), nivalenol (NIV), T-2 toxin, HT-2 toxin], zearalenone (ZEA) and fumonisins (FUM). The metabolites were identified using HPLC methods with fluorescent, UV and MS/MS detection. Both immunoaffinity and SPE columns were used for sample preparation. In eleven samples, the concentration of several mycotoxins exceeded the recommended guidelines for feedstuffs. DON was detected at the highest concentration in the majority of analysed samples (cereal grains, silages and mixed feeds, maximum values ranged from 409 to 14,470 ng/g). Corn grains also contained other Fusarium toxins (FUM) at maximum levels ranging from 435 to 9409 ng/g. The highest average(positive) concentration of the other trichothecenes (NIV, T-2 and HT-2 toxins) was <5.0-139 ng/g. ZEA was found at the highest concentration in corn grains and silages (maximum values ranging from 292 to 603 ng/g and 116 to 1150 ng/g, respectively). The highest average(positive) concentration and the maximum level of OTA were detected in cereal grains (33.0 ng/g in 2009 and 760 ng/g in 2007, respectively). Less than 7% of the 557 samples were contaminated with AF at low levels (maximum of 0.61 ng/g). Our results support the need for further monitoring of mycotoxins in Polish feedstuffs and their components.

Swine production workers are exposed simultaneously to multiple contaminants. Occupational exposure to aflatoxin B1 (AFB1) in Portuguese swine production farms has already been reported. However, besides AFB1, data regarding fungal contamination showed that exposure to other mycotoxins could be expected in this setting. The present study aimed to characterize the occupational exposure to multiple mycotoxins of swine production workers. To provide a broad view on the burden of contamination by mycotoxins and the workers’ exposure, biological (urine) samples from workers (n = 25) and 38 environmental samples (air samples, n = 23; litter samples, n = 5; feed samples, n = 10) were collected. The mycotoxins biomarkers detected in the urine samples of the workers group were the deoxynivalenol-glucuronic acid conjugate (60%), aflatoxin M1 (16%), enniatin B (4%), citrinin (8%), dihydrocitrinone (12%) and ochratoxin A (80%). Results of the control group followed the same pattern, but in general with a lower number of quantifiable results (<LOQ). Besides air samples, all the other environmental samples collected presented high and diverse contamination, and deoxynivalenol (DON), like in the biomonitoring results, was the most prominent mycotoxin. The results demonstrate that the occupational environment is adding and contributing to the workers’ total exposure to mycotoxins, particularly in the case of DON. This was confirmed by the biomonitoring data and the high contamination found in feed and litter samples. Furthermore, he followed multi-biomarker approach allowed to conclude that workers and general population are exposed to several mycotoxins simultaneously. Moreover, occupational exposure is probably described as being intermittent and with very high concentrations for short durations. This should be reflected in the risk assessment process.