Comparative aspects of Fusarium mycotoxicoses in poultry fed diets containing naturally contaminated grains

Performance effects of feed-borne Fusarium mycotoxins on broiler chickens: Influences of timing and duration of exposure

In commercial practice, broiler chickens may be exposed to Fusarium mycotoxins either during specific growth stages or throughout the entire production cycle. A 34-day feeding trial was conducted to identify sensitive periods for mycotoxin effects during the growth cycle of broiler chickens. A total of 420 newly-hatched Ross 308 male broilers were randomly assigned to 60 cages with 7 birds/cage. Sources of clean wheat (<0.5 mg/kg deoxynivalenol [DON]) and Fusarium-contaminated wheat (11.4 mg/kg DON) were used to formulate the starter diets (0.41 and 6.62 mg/kg DON) provided from 1 to 21 d of age and the grower diets (0.54 and 7.90 mg/kg DON) provided from 22 to 34 d. Control and DON diets were provided to broilers according to treatments (control, DON 1 to 14 d, DON 15 to 21 d, DON 22 to 34 d and DON 1 to 34 d). Birds were monitored daily for morbidity or mortality. Broiler growth performance (body weight, average daily gain, average daily feed intake and feed to gain ratio) was measured weekly. Segments of duodenum, jejunum and ileum were collected at 21 and 34 d and morphometric parameters (villus height, crypt depth, villus width, muscularis thickness and villi:crypt ratio) were measured. Birds fed the DON starter diet during the first 14 d did not exhibit any changes in growth performance; however, growth performance was suppressed in birds fed DON-contaminated diets during the grower period (22 to 34 d). At 34 d, birds that received the DON grower diet (DON 22 to 34 d and DON 1 to 34 d) were lighter (1,433 vs. 1,695 g) than birds fed the control diet. Feed to gain ratio was higher in birds fed the DON grower diet from 22 to 28 d (1.77 vs. 1.56) and 28 to 34 d (2.24 vs. 1.85) compared with corresponding controls. These results suggest that providing older broiler chicks (22 to 34 d) feed contaminated with Fusarium mycotoxins (specifically DON) may result in production losses. Histopathological analysis of the ileum region revealed that birds provided the DON diets throughout the entire trial (1 to 34 d) had shorter villi (506 vs. 680 μm) and shallower crypt (85 vs. 115 μm) than control birds. Taken together, these results indicate that DON-induced growth suppression may be a result of adverse effects on intestinal morphology during later growth phases of broilers.

Evaluation of Microbiological and Chemical Contaminants in Poultry Farms

The aim of the study was to evaluate the microbiological and chemical contamination in settled dust at poultry farms. The scope of research included evaluating the contributions of the various granulometric fractions in settled dust samples, assessing microbial contamination using culture methods, concentrations of secondary metabolites in dust and their cytotoxicity against hepatocyte chicken cells by means of MTT (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide) tests. In addition, we also evaluated the concentration of selected volatile odorous compounds (VOCs) using gas chromatographic and spectrophotometric methods and airborne dust concentration in the air with DustTrak™ DRX Aerosol Monitor. Studies were carried out on chicken broilers and laying hens at 13 poultry farms, with numbers of birds ranging from 8000 to 42,000. The airborne total dust concentration at poultry farms averaged 1.44 mg/m³ with a high percentage of the PM10 fraction (particulate matter with a diameter less than 10 μm). Microorganism concentrations in the settled dust were: 3.2 × 10⁸ cfu/g for bacteria and 1.2 × 10⁶ cfu/g for fungi. Potential pathogens (Enterococcus spp., Escherichia coli, Salmonella spp., Aspergillus fumigatus, Paecilomyces variotii) were also found. Secondary metabolites included aurofusarin, deoxynivalenol, 15-hydroxyculmorin zearalenone, zearalenone-sulfate, infectopyron, and neochinulin A. However, the dust samples showed weak cytotoxicity towards chicken hepatocyte cells, which ranged between 9.2% and 29.7%. Among volatile odorous compounds ammonia, acrolein, methyloamine, acetic acid, acetoaldehyde and formaldehyde were detected in the air. In conclusion, settled dust can be a carrier of microorganisms, odours and secondary metabolites in poultry farms, which can be harmful to workers' health.

Toxicokinetic study and oral bioavailability of deoxynivalenol in turkey poults, and comparative biotransformation between broilers and turkeys

The aim of present study was to reveal the toxicokinetic properties and absolute oral bioavailability of deoxynivalenol (DON) in turkey poults. Six turkey poults were administered this Fusarium mycotoxin per os and intravenously in a two-way cross-over design. Based on non-compartmental analysis, DON was absorbed rapidly (Tmax= 0.57 h) but incomplete, as the oral bioavailability was only 20.9%. DON was rapidly eliminated as well, both after oral (T1/2elimination PO=0.86 h) as well as intravenous (IV) (T1/2elimination IV = 0.62 h) administration. Furthermore, semi-quantitative analysis using high-resolution mass spectrometry revealed that DON-3α-sulphate is the major metabolite of DON in turkeys after IV as well as oral administration, with DON-3α-sulphate/DON ratios between 1.3-12.6 and 32.4-140.8 after IV and oral administration, respectively. Glucuronidation of DON to DON-3α-glucuronide is a minor pathway in turkey poults, with DON-3α-glucuronide/DON ratios between 0.009-0.065 and 0.020-0.481 after IV and oral administration, respectively. Only trace amounts of other metabolites were found including 10-DON-sulphonate, de-epoxydeoxynivalenol and 10-de-epoxydeoxynivalenol-sulphonate. In addition, a similar two-way cross-over study was performed in three broiler chickens, in order to compare the biotransformation of DON in both poultry species. High-resolution mass spectrometry revealed that DON-3α-sulphate was the major metabolite of DON in broiler chickens as well, with DON-3α-sulphate/DON ratios between 243-453 and 1,365-29,624 after IV and oral administration, respectively. These ratios indicate that broiler chickens metabolise DON even more extensively to the sulphate conjugate compared to turkey poults. Only trace amounts of other metabolites were detected in broiler chickens. In conclusion, it can be stated that the toxicokinetic behaviour of DON in broiler chickens and turkey poults is comparable (low absolute oral bioavailability, rapid absorption and elimination, extensive biotransformation to DON-3α-sulphate), however, relative differences in DON-3α-sulphate/DON ratios exist between both species which might explain the hypothesised difference in sensitivity of both poultry species to DON.

Effects of feeding deoxynivalenol (DON)-contaminated wheat to laying hens and roosters of different genetic background on the reproductive performance and health of the newly hatched chicks

A total of 216 23-week-old laying hens from two different genetic backgrounds (half of the birds were Lohmann brown [LB] and [LSL] hens, respectively) and 24 adult roosters were assigned to a feeding trial to study the effect of increasing concentrations of deoxynivalenol (DON) in the diet (0, 5, 10 mg/kg) on the reproductive performance of hens and roosters, and the health of the newly hatched chicks. Hatchability was adversely affected by the presence of DON in LB hens' diet, while the hatchability of the LSL chicks was significantly higher than LB chicks. An interaction effect between DON in the hens' diet and the breed was noticed on fertility, as the fertility was decreased in the eggs of LB hens receiving 10 mg/kg DON in their diet and increased in the eggs of LSL hens fed 10 mg/kg DON. Moreover, spleen relative weight was significantly decreased in the chicks hatched from eggs of hens fed contaminated diets, while gizzard relative weight was significantly decreased in LB chicks with 10 mg/kg DON in their diet compared with the control group. On the other hand, the chicks' haematology and organ histopathology were not affected by the dietary treatment. Additionally, the presence of DON in the roosters' diet had no effect on fertility (the percentage of fertile eggs of all laid eggs). Consequently, the current results indicate a negative impact of DON in LB hens' diet on fertility and hatchability, indicating that the breed of the hens seems to be an additional factor influencing the effect of DON on reproductive performance of the laying hens.