An impact of Deoxynivalenol produced by Fusarium graminearum on broiler chickens

Deoxynivalenol (DON; vomitoxin) is a trichothecene mycotoxin that is produced by Fusarium graminearum (F. graminearum) and is prevalently found in grains such as wheat, corn, barley and their by-products. Food and feed contaminated with DON cause a variety of adverse health effects in humans and farm animals.

Poultry are also adversely affected by DON but less susceptible due to differences in DON metabolism. Because of the differences in breeds, types of diet and strains of poultry, it was found that the deleterious effects of DON on growth performance in poultry are inconsistent. Overall, the main effect in poultry at low concentrations of dietary DON was found to be a reduction in feed consumption, whereas higher doses of dietary DON appear to reduce body weight and cause development of lesions of the gastrointestinal tract, especially in the duodenum and jejunum. The purpose of this study was to investigate the effects of DON toxic effects on broilers.

Fifty-four one-day-old broilers (Ross 308) were randomly allocated to three different treatment groups (n = 18 per group): (i) basal diet (control), (ii) basal diet plus 5 mg/kg of DON and (iii) basal diet plus 5 mg/kg of DON and 1.5 g/kg antidote (Toxi-free PLUS, Life Rainbow Biotech Co., Ltd., Yilan, Taiwan).

At the end of the experiment, broilers were sacrificed by cervical dislocation. The spleen, bursa of Fabricius and small intestine were excised and weighed. The blood was collected and centrifuged to harvest serum for biochemistry.

Results showed that the villus height was significantly reduced in the duodenum of the DON treatment group compared with the control group while the antidote alleviated the damage caused by DON. A similar effect was observed in the ratio of villus height and crypt depth (Table 1).

We found that DON significantly increased COX-2 mRNA expression in the spleen compared with the control group, whereas the antidote supplement efficiently reversed the effects on COX-2 mRNA expression (Figure 1a). A slight increase in iNOS and IL-1β mRNA expression was observed  in the DON-treated group (Figure 1b and c). Similarly, COX-2 mRNA expression was elevated in the bursa of Fabricius of the DON-treated group compared with the control group (Figure 2a). The antidote supplement significantly abolished the effect caused by DON on COX-2 mRNA expression (Figure 2a). iNOS expression and IL-1β mRNA expression were significantly reduced in DON treatment in combination with the antidote group compared with DON treatment alone (Figure 2b and c).

In feeding trial experiments, the villus height and the ratio of villus height and crypt depth were reduced in the duodenum of DON-fed broilers, whereas degradation agent of mycotoxin could efficiently reverse the abnormal morphology of the small intestine in the DON- fed broilers. Furthermore, the expression of pro-inflammatory gene, COX-2, was induced in the spleen and bursa of Fabricius of DON-fed broilers. DON in dietary feed could cause abnormal morphology of the small intestine in broilers. DON induce an abnormal morphology of the small intestine, particularly the duodenum.

Figure 1. Effects of Deoxynivalenol and antidote on pro- inflammatory mRNA expression in spleen of 28-day-old broilers. (a) COX-2, (b) iNOS, (c) IL-1β and (d) TNF-α. Values were expressed as mean ± SD (n = 18). Different letters above the bars indicate significant differences between the means (p < .05)

Figure 2. Effects of Deoxynivalenol and antidote on pro- inflammatory mRNA expression in bursa of Fabricius of 28-day-old broilers. (a) COX-2, (b) iNOS, (c) IL-1β and (d) TNF-α. Values were expressed as mean ± SD (n = 18). Different letters above the bars indicate significant differences between the means (p < .05)