Why Mycotoxins Matter in Broiler Production

The negative impacts of mycotoxins in poultry can be far-reaching, decreasing gastrointestinal integrity, immunity and performance in broilers and resulting in economic losses. Given the high rates of mycotoxin in poultry feed, a mycotoxin risk management strategy is needed to reduce the challenges in poultry production and ensure profitability.

Poultry producers frequently ask: What is the real impact of mycotoxins on the broiler’s productivity? What sounds like an easy question is, in the case of mycotoxins, unfortunately not so easy to answer.

Three key considerations to evaluate the impact of mycotoxins on a poultry farm:

1. Measure the contamination levels in ingredients and finished feed
2. Include mycotoxins as potential predisposing factors to health challenges
3. Assess low level mycotoxin contamination on performance and profitability

Mycotoxins are frequently found in poultry feed. According to the dsm-firmenich World Mycotoxin Survey, more than 33,000 analysis of finished poultry feed tested positive for mycotoxins in the last ten years (2013 – 2023). A closer analysis of this data shows that 83% of these samples are contaminated with more than one mycotoxin (Figure 1) and as many as 50 mycotoxins were found in a single sample. Exposure to multiple mycotoxins at the same time can often lead to more severe effects on health and performance of birds. Therefore, it is of utmost importance to measure a panel of mycotoxins to have a more robust risk evaluation (Figure 2).

Testing the finished feed and/or their ingredients helps to evaluate the risk for the bird’s health. The frequent presence of mycotoxins triggers the gut health and immune system of the animals, consequently reducing the performance of the flocks, what can be translated as a loss of profit for poultry producers.

The lack of visible clinical signs is primarily due to the short life cycle of broilers. This means that the challenge may lurk within the animal, but not have time to manifest outwardly. The combined effects of more than one mycotoxin make the diagnosis more difficult. However, the major impacts of mycotoxins on in poultry health and have been clearly proven: destruction of the villus of the intestines which harms nutrient absorption and digestion while increasing leaky gut and modulation of the local immune response and the microbiota which increases the opportunity for vaccine failure and dysbiosis.

• Decreased nutrient absorption: Mycotoxins, especially deoxynivalenol (DON) and fumonisins (FUM), affect several aspects of intestinal integrity. A meta-analysis (Grenier and Applegate, 2013) showed a clear influence of DON and FUM in (figure 3). Mycotoxins reduce the functionality of tight-junctions between the intestinal cells, opening up the opportunity for pathogens and antinutritional factors to move from the intestinal barrier to the bloodstream. This challenges the immune system and liver, redirecting nutrients and energy away from growth. The liver is directly affected by most mycotoxins. In broilers, a visible fatty degeneration, and an increase of approximately 15% in liver weight were reported. This reflects an increased cost of nutrients and amino acids, especially methionine which is the first limiting amino acid for broilers. A strategy that directly deactivates mycotoxins is the greatest opportunity to prevent the nutritional losses without having to manage nutritional changes in the diet.

• Vaccination failure: Modulation of immune response is one of the main modes of action of mycotoxins which can impact how birds respond diseases challenges and vaccination practices. Mycotoxins act as a predisposing factor to reduce the immunity for viral diseases in broilers (Kamalavenkatesh et al., 2005; Hanif and Muhammad, 2015 and Yunus et al., 2012). Ochratoxin, DON, T2, cyclopiazonic acid significantly reduced the antibody titer for Newcastle disease virus (NDV), infectious bronchitis virus (IBV), infectious bursal disease virus (IBDV), and hydropericardium syndrome (HPS). It increases the susceptibility of birds to infectious diseases that could be avoided under normal conditions.
• Predisposition for Coccidiosis and Necrotic Enteritis (NE): Antonissen et al. (2014) evidenced that low to moderate doses of different Fusarium mycotoxins (DON, NIV, FB1, T-2, ZEN) predisposed birds to a more severe response to a coccidiosis and NE challenge as shown with reduced immune response and efficacy of the anticoccidial treatment. Additionally, FB1 and DON contamination resulted in a more severe NE challenge in separate studies (Antonissen et al., 2012 and Antonissen et al., 2015). Coccidiosis is one of the most costly diseases in poultry production. By monitoring and reducing mycotoxins, coccidiosis management strategies can be more effective.
• Food safety contamination: Evidence of a higher susceptibility to Salmonella typhimurium and Campylobacter jejuni were also reported in the presence trichothecenes (DON and T2), suggesting that these compounds may modulate the bacterial metabolism. As previously described, mycotoxins result in a ‘leaky gut’. Once the junctions between intestinal cells are disrupted, an exchange of molecules happens between the intestine and the bloodstream. This condition can influence the carcass contamination during processing by:
  • The excess of proteins in the intestinal lumen supports higher contamination of pathogenic bacteria such as Salmonella sp and Campylobacter jejuni,
  • The higher amount of water in the gut lumen leading to more leaky excreta.

By mitigating mycotoxin risk, the opportunity for ‘leaky gut’ is minimized further supporting the production of safe poultry products.

Performance is one of the most important factors in poultry production profitability. A data compilation of scientific trials has shown that the presence of mycotoxins in poultry diets significantly reduced (P < 0.05) feed intake by 12% and body weight gain (BWG) by 14%, resulting in an impaired feed conversion ratio (FCR) of 7% when compared with non-contaminated groups (Andretta et al, 2011).

Furthermore, results from a cooperation project with the University of Ghent (Antonissen et al., 2018) show a synergistic negative effect between a dysbiosis challenged diet and additional DON (5 mg/kg) and FB1 (20 mg/kg) on broilers’ performance. These data demonstrate that the reduction in performance is sustained through the final phase of production. (Figure 4).

In a long-term evaluation (18 successive trials) of a commercial farm, it was shown that natural contamination with levels below the EU recommendations for mycotoxins has a significant impact of 2.5 points in FCR (Figure 5), confirming the synergistic effects of the mycotoxins (fumonisins, zearalenone, DON and DAS) and the decreased broiler performance in commercial conditions (Kolawole et al., 2020).

Mycotoxins have direct and indirect effects on coccidiosis, food safety, and broiler performance which directly influence the profitability of the producer. Due to the frequent occurrence of mycotoxins in poultry feed, a mycotoxin risk management strategy is needed to protect broilers in all phases and ensure profitability. DSM offers the most comprehensive solution on the market: Our survey which is longest running and most comprehensive data set on mycotoxin occurrence to give insights on which mycotoxins maybe present in your feed, our analytical services to support mycotoxin detection in your ingredients, and our Mycofix® portfolio of feed additives which represent the most state-of-the-art solution for protecting bird health by deactivating mycotoxins that contaminate feed.

References

Andretta, I., Kipper, M., Lehnen, C. R., Hauschild, L., Vale, M. M., & Lovatto, P. A. (2011). Meta-analytical study of productive and nutritional interactions of mycotoxins in broilers. Poultry Science, 90(9), 1934-1940.

Antonissen, G., Croubels, S., Pasmans, F., Ducatelle, R., Haesebrouck, F., Timbermont, L., ... & Delezie, E. (2012). The mycotoxin deoxynivalenol predisposes for the development of necrotic enteritis in broilers. In 1st ihsig International symposium (IHSIG 2012): Intestinal health management in tomorrow's poultry industry. Intestinal Health Scientific Interest Group (ihsig).

Antonissen, G., Martel, A., Pasmans, F., Ducatelle, R., Verbrugghe, E., Vandenbroucke, V., ... & Croubels, S. (2014). The impact of Fusarium mycotoxins on human and animal host susceptibility to infectious diseases. Toxins, 6(2), 430-452.

Antonissen, G., Croubels, S., Pasmans, F., Ducatelle, R., Eeckhaut, V., Devreese, M., ... & Antlinger, B. (2015). Fumonisins affect the intestinal microbial homeostasis in broiler chickens, predisposing to necrotic enteritis. Veterinary Research, 46(1), 98.

Antonissen, G, Van Immerseel F., and Croubels S. (2018). Toward an integrative understanding 
of the impact of mycotoxins on gut health. World Nutrition Forum. October 3rd, 2018. Cape Town, South Africa.  

Grenier, B., & Applegate, T. J. (2013). Modulation of intestinal functions following mycotoxin ingestion: Meta-analysis of published experiments in animals. Toxins, 5(2), 396-430.

Hanif, N. Q., & Muhammad, G. (2015). Immunotoxicity of ochratoxin A and role of Trichosporon mycotoxinivorans on the humoral response to infectious viral disease vaccines in broilers. Pakistan Journal of Zoology, 47(6).

Kamalavenkatesh, P., Vairamuthu, S., Balachandran, C., & Manohar, B. M. (2005). Immunopathological effect of the mycotoxins cyclopiazonic acid and T-2 toxin on broiler chicken. Mycopathologia, 159(2), 273-279.

Kolawole, O., Graham, A., Donaldson, C., Owens, B., Abia, W. A., Meneely, J., Alcorn, M. J., Connolly. L. & Elliott, C. T. (2020). Low Doses of Mycotoxin Mixtures below EU Regulatory Limits Can Negatively Affect the Performance of Broiler Chickens: A Longitudinal Study. Toxins, 12(7), 433.

Yunus, A. W., Ghareeb, K., Twaruzek, M., Grajewski, J., & Böhm, J. (2012). Deoxynivalenol as a contaminant of broiler feed: effects on bird performance and response to common vaccines. Poultry science, 91(4), 844-851.