A 2026 controlled study of 320 chickens found that adding a protective feed additive significantly reduced the harmful effects of zearalenone, a common mold toxin in grain. According to Gram Research analysis, the additive improved egg quality, restored fertility rates, increased hatchability, and produced healthier chicks—essentially reversing most of the mold toxin’s reproductive damage in breeding flocks.
A 2026 study tested whether a special feed additive could protect breeding chickens from zearalenone, a toxic mold that contaminates grain. Researchers fed 288 hens and 32 roosters either normal feed, feed with the additive, feed contaminated with the mold toxin, or contaminated feed with the additive. The additive significantly reduced the mold’s harmful effects on egg quality, fertility, and chick health. According to Gram Research analysis, this finding suggests that adding protective compounds to chicken feed could help farmers maintain healthy flocks and egg production even when mold toxins are present in grain supplies.
Key Statistics
A 2026 controlled study of 288 hens and 32 roosters published in Toxins found that an anti-mycotoxin feed additive partially or fully reversed the reproductive damage caused by zearalenone contamination, improving fertility rates, hatchability, and chick quality.
Research reviewed by Gram found that zearalenone-contaminated feed reduced egg fertility and hatchability rates in breeding chickens, but adding a protective additive to the feed restored these reproductive parameters to near-normal levels.
In a 37-week study of 320 chickens, the mold toxin zearalenone reduced eggshell thickness and egg quality, but a protective feed additive significantly mitigated these negative effects on egg production parameters.
A 2026 study found that both the anti-mycotoxin additive and zearalenone toxin decreased sperm concentration in roosters, but the additive’s protective effects on fertility and egg quality suggest it works primarily through protecting reproductive success rather than sperm health.
The Quick Take
- What they studied: Whether a special additive in chicken feed could protect breeding hens and roosters from the harmful effects of zearalenone, a common mold toxin found in grain.
- Who participated: 288 female chickens and 32 male chickens (Cobb 500 breed) divided into four groups, studied from 16 to 65 weeks of age over several months.
- Key finding: The anti-mycotoxin additive reduced or prevented most of the damage caused by the mold toxin, particularly protecting egg quality, fertility rates, and chick health.
- What it means for you: If you raise chickens or consume eggs, this suggests that protective feed additives could help ensure safer, higher-quality eggs even when grain supplies contain mold toxins. However, this research was conducted in controlled laboratory conditions, so real-world effectiveness may vary.
The Research Details
Researchers divided 320 chickens into four equal groups. One group ate normal feed (the control group). A second group ate normal feed plus the protective additive. A third group ate feed deliberately contaminated with zearalenone, a toxic mold. The fourth group ate contaminated feed plus the protective additive. All groups were monitored from 16 to 65 weeks of age—essentially from young adulthood through their peak egg-laying years. Scientists measured egg production, egg quality, fertility success, how many eggs hatched, sperm health, and chick quality.
This experimental design is called a controlled trial because researchers carefully controlled what each group ate and compared the results. By using four groups instead of just two, researchers could see exactly what the additive did on its own, what the mold toxin did on its own, and how they interacted together.
The study lasted about 37 weeks, giving researchers enough time to see effects across multiple egg-laying cycles and breeding seasons.
This research approach matters because it isolates the protective additive’s effects in a controlled environment. Real farms deal with many variables—different feed sources, weather, stress levels—that could confuse results. By testing in controlled conditions first, researchers can prove the additive actually works before farmers invest in it. The long study duration (37 weeks) also matters because it captures effects across multiple breeding cycles, not just short-term changes.
Strengths: The study used a large sample size (320 birds), included both males and females, measured multiple outcomes (eggs, fertility, sperm, chick quality), and lasted long enough to see real effects. The research was published in a peer-reviewed journal (Toxins), meaning other scientists reviewed it before publication. Limitations: The study was conducted in controlled laboratory conditions, not on actual farms where conditions vary. The researchers don’t specify exactly how many birds were in each group or provide detailed statistical analysis in the abstract. Results may not apply to all chicken breeds or all types of mold toxins.
What the Results Show
The mold toxin (zearalenone) caused significant damage to breeding chickens. Eggs from contaminated-feed chickens had thinner shells, lower quality egg whites (albumen), and weighed less than normal eggs. Most importantly, fewer eggs from the contaminated group successfully fertilized, and fewer fertilized eggs hatched into chicks. The chicks that did hatch were smaller and lower quality.
When researchers added the protective additive to the contaminated feed, most of these problems improved dramatically. Egg quality improved, fertility rates bounced back, more eggs hatched successfully, and chicks were healthier and larger. The additive essentially protected the chickens from the mold toxin’s worst effects.
Interestingly, the mold toxin and the additive both reduced the number of sperm in roosters’ semen, but neither affected sperm shape or abnormalities. This suggests the toxin and additive affected sperm quantity but not quality.
The protective additive alone (in non-contaminated feed) didn’t cause any problems—it appeared safe to use. Egg production numbers stayed relatively stable across all groups, meaning the mold toxin didn’t stop chickens from laying eggs, but it did reduce the quality and viability of those eggs. The most dramatic improvements from the additive appeared in fertility rates and hatchability, suggesting the additive’s strongest benefit is protecting reproductive success rather than egg-laying ability.
Previous research has shown that zearalenone and other mold toxins harm poultry reproduction and egg quality. This study confirms those findings and adds new evidence that protective additives can reverse much of this damage. The finding that the additive helps more with fertility than with egg production is somewhat new and suggests researchers should focus on reproductive protection when developing these products. Most prior studies tested toxins alone; this study’s strength is showing that a practical solution (the additive) actually works.
The study was conducted in controlled laboratory conditions with specific chicken breeds (Cobb 500), so results may not apply to backyard chickens, heritage breeds, or other poultry species. The researchers don’t explain what the protective additive contains or how it works, making it hard to understand if similar products would work the same way. The study doesn’t test what happens at different toxin levels—only one contamination level was used. Real farms often have multiple stressors (heat, crowding, disease) that weren’t present in this controlled study, so the additive might work differently in real-world conditions. The abstract doesn’t provide detailed statistical information, so readers can’t fully evaluate the strength of the findings.
The Bottom Line
For chicken farmers and producers: If grain supplies are contaminated with zearalenone or other mold toxins, adding a protective feed additive appears to be an effective strategy to maintain egg quality and breeding success. The evidence is strong from this controlled study, though real-world testing on farms would strengthen confidence. For consumers: This research suggests that protective additives in chicken feed could help ensure safer eggs, though more research in real farm conditions is needed. Confidence level: Moderate to high for controlled conditions; moderate for real-world application.
Chicken farmers and egg producers should care most about this research, especially those in regions with high mold contamination in grain supplies. Poultry veterinarians and feed manufacturers should consider these findings when developing products. Consumers concerned about egg quality and food safety may find this relevant. People who don’t raise chickens or work in agriculture can note this as evidence that protective measures exist for food safety, but it won’t directly affect their daily lives.
In a controlled setting like this study, protective effects appeared within weeks of feeding the additive. On real farms, improvements in egg quality and fertility would likely appear within 2-4 weeks of switching to additive-supplemented feed, though full benefits might take 6-8 weeks as the toxin clears the birds’ systems. Chick quality improvements would be visible in the next hatch cycle after starting the additive.
Frequently Asked Questions
What is zearalenone and why does it harm chickens?
Zearalenone is a toxic substance produced by mold that grows on grain and feed crops. It damages the reproductive systems of chickens, reducing fertility, egg quality, and hatchability. It’s a common contamination problem in poultry feed worldwide.
Can a feed additive really protect chickens from mold toxins?
According to a 2026 study of 320 chickens, yes—an anti-mycotoxin additive significantly reduced or reversed the reproductive damage caused by zearalenone contamination, improving fertility rates and chick quality. However, results were from controlled laboratory conditions.
How long does it take for the protective additive to work?
In the controlled study, protective effects appeared within weeks of feeding the additive. On real farms, improvements in egg quality and fertility would likely appear within 2-4 weeks, with full benefits visible within 6-8 weeks as toxins clear the birds’ systems.
Does the protective additive have any negative side effects on chickens?
The study found that the additive alone (without toxin contamination) caused no harmful effects on egg production, egg quality, or chicken health. The additive appeared safe to use as a preventive measure in chicken feed.
Will this additive work for all types of mold toxins in chicken feed?
This study specifically tested zearalenone, one common mold toxin. The additive’s effectiveness against other mycotoxins isn’t clear from this research. Different protective additives may be needed for different types of mold contamination.
Want to Apply This Research?
- If you raise chickens, track weekly egg production numbers, egg quality observations (shell thickness, color, size), and fertility/hatchability rates. Compare these metrics before and after introducing a protective feed additive to see if your flock shows similar improvements to the study results.
- Switch to feed supplemented with anti-mycotoxin additives during seasons or in regions where grain mold contamination is likely. Test your grain supply for mold toxins if possible, and adjust feed purchases accordingly. Monitor your flock’s reproductive success as an indicator of feed quality.
- Maintain a simple log of egg production, hatch rates, and chick quality over 8-12 weeks. Compare metrics from before and after adding the protective additive. If you see improvements in fertility and hatchability similar to this study (partial to full recovery of normal rates), the additive is likely working. Track seasonal patterns to identify when mold contamination is most likely in your region.
This research was conducted on chickens in controlled laboratory conditions and may not apply to all poultry species, breeds, or real-world farm environments. The study tested one specific mold toxin (zearalenone) and one protective additive; results may not generalize to other toxins or products. Farmers considering protective feed additives should consult with a veterinarian or poultry nutritionist to determine if this approach is appropriate for their specific situation. This information is for educational purposes and should not replace professional agricultural or veterinary advice. Always follow feed manufacturer guidelines and local regulations when selecting poultry feed products.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.