Mycotoxins are naturally occurring, toxic secondary metabolites produced by fungi that can be found in feedstuffs such as cereal grains and their byproducts. The consumption of mycotoxins by poultry animals can result in several effects, both direct and indirect.

A recently published meta-analysis titled “Meta-Analysis of the Effects of Yeast Cell Wall Extract Supplementation during Mycotoxin Challenges on the Performance of Laying Hens,” authored by Dr. Alexandra Weaver, Dr. Daniel Weaver, Nick Adams and Dr. Alexandros Yiannikouris, explores the impact of yeast cell wall extract (YCWE, Mycosorb®, Alltech) on laying hens facing mycotoxin challenges.

Understanding the Study

A meta-analysis is a statistical technique used in research to combine and analyse results from multiple independent studies on a particular topic. The process involves literature reviews, the use of inclusion and exclusion criteria, data extraction, statistical analysis, and interpretation of the results. Meta-analysis is particularly useful when individual studies may have limitations, or when there is a need for a more robust, reliable and comprehensive understanding.

25 trials investigating the use of YCWE in hens were found following the literature search, with 8 trials being selected that met selection inclusion. These selected trials represent 12 treatments involving 1,774 laying hens. The average length of the trials was 9.5 weeks. Treatments included control (CTRL), challenge with mycotoxins (MT), and use of YCWE during a mycotoxin challenge (YCWE+MT).

A total of 8 mycotoxin types were identified:

• Aflatoxin (AF): Produced by Aspergillus flavus mold, typically during warm and dry field conditions or in the presence of high moisture levels during crop storage. AF causes a variety of effects in animals, including organ damage, poor growth or efficiency, and higher mortality.

• Ochratoxin A (OTA): Produced by Penicillium molds. Poultry that ingest this toxin may show reduced growth and immunity, damage to kidneys or other internal organs, dehydration, or higher mortality.

• Deoxynivalenol (DON)/15-acetyl-DON (15ADON)/ DON-3-glucoside (DON-3-G): Members of the type B trichothecenes family, produced by Fusarium molds. When consumed by poultry, these toxins can cause digestive disorders, lower feed intake and growth, reduced immunity, and damage to internal organs.

• T2-toxin (T2): A member of the type A trichothecenes family, T2 is produced by Fusarium molds. This mycotoxin can have a strong impact on the digestive system, causing oral and gut lesions as well as hemorrhagic and other digestive disorders. Affected birds may also have poor growth or feed intake, damage to internal organs, and increased mortality.

• Fumonisins (FUM): Produced by Fusarium moulds, often when dry and warm conditions during crop flowering are followed by wet and warm temperatures closer to harvest. FUM can cause digestive disorders, alter immune response, and damage internal organs.

• Zearalenone (ZEA): Produced by Fusarium species, ZEA mimics the action of hormones as an oestrogen analogue. This can lead to reproductive challenges. ZEA can also hamper immunity.

To compare the mycotoxin scenarios included in the research to real-life, we can look at the results of extensive Alltech 37+® laboratory analysis over the past 3 years. A total of 848 samples of finished feeds for layers/ breeders, gathered from locations around the world, showed an average of 8.2 mycotoxins per sample, with 97% of samples containing 2 or more mycotoxins. This is significant because multiple-mycotoxin challenges can increase the overall risk to the bird, combining to cause even greater damage than each toxin would cause on its own.

Additionally, some of the most prevalent mycotoxin groups in these feed samples were similar to those used in the studies in this meta-analysis, including the type B trichothecenes (found in 86% of samples), fumonisins (79%) and zearalenone (41%). As such, the results of the meta-analysis could be applied to the typical laying/breeding hen.

Other notable mycotoxins of high occurrence in feed samples collected globally included emerging mycotoxins (89%) and fusaric acid (85%), though these were not included in the majority of tests conducted for research trials.