According to Gram Research analysis, adding 300 mg of bile acids per kilogram of feed significantly improved egg production and quality in aging laying hens. A 2026 controlled study of 1,080 hens found that this supplement increased laying rates, improved egg white thickness and yolk color, and reduced the amount of feed needed per egg. The hens also showed better nutrient absorption and healthier reproductive organs, suggesting bile acids could help older flocks remain productive longer.
Researchers tested whether adding bile acids—natural substances that help digest fats—to chicken feed could improve egg production in older laying hens. They studied 1,080 hens that were 76 weeks old and gave some hens feed with different amounts of bile acids for 35 days. The results showed that hens receiving 300 mg of bile acids per kilogram of feed produced more eggs, laid better-quality eggs, and digested their food more efficiently. This finding suggests bile acids could be a practical way to keep older hens productive longer.
Key Statistics
A 2026 controlled study of 1,080 laying hens found that dietary supplementation with 300 mg of bile acids per kilogram of feed produced the most pronounced improvements in egg production, egg quality, and nutrient digestibility compared to unsupplemented hens.
Research published in Poultry Science showed that hens receiving 300 mg/kg bile acid supplementation significantly increased their Haugh unit (egg white thickness) and yolk color while decreasing the feed-to-egg ratio, meaning they needed less feed to produce each egg.
A 35-day study of 1,080 aging laying hens demonstrated that bile acid supplementation increased the apparent digestibility of dry matter, crude protein, and all measured amino acids, with the 300 mg/kg dose showing the greatest improvements across all nutrient categories.
Microscopic examination in the 2026 study revealed that 300 mg/kg bile acid supplementation significantly increased oviductal mucosal fold height and uterine epithelial height in aging laying hens, indicating improved reproductive organ development.
The Quick Take
- What they studied: Whether adding bile acids (natural fat-digesting compounds) to chicken feed helps older laying hens produce more and better eggs
- Who participated: 1,080 Hy-Line Brown laying hens that were 76 weeks old (equivalent to a chicken in her senior years), divided into four groups receiving different amounts of bile acid supplement
- Key finding: Hens that received 300 mg of bile acids per kilogram of feed showed the biggest improvements in egg production, egg quality, and how well they digested nutrients compared to hens receiving no supplement
- What it means for you: If you raise chickens or work in poultry farming, adding bile acids to feed could help older hens stay productive longer. However, this research was done in controlled farm settings, so results may vary in different environments
The Research Details
Scientists divided 1,080 older laying hens into four equal groups. One group received regular feed with no supplement (the control group), while the other three groups received feed with increasing amounts of bile acids: 200, 300, or 500 mg per kilogram of feed. All hens ate their assigned diet for 35 days while researchers carefully measured egg production, egg quality, how well they digested food, and changes in their reproductive organs and intestines.
This type of study is called a controlled experiment because researchers kept everything the same except for the bile acid amounts. This design helps prove that any differences in egg production were caused by the bile acids, not by other factors like temperature or feed quality.
The researchers measured many outcomes including how many eggs each hen laid, the thickness and color of egg whites and yolks, how much of each nutrient the hens’ bodies actually absorbed, and even examined the physical structure of their reproductive organs under a microscope.
This research approach is important because it tests a practical solution to a real problem in chicken farming: older hens naturally produce fewer and lower-quality eggs. By testing different amounts of bile acids, researchers could identify the exact dose that works best. The detailed measurements of both egg quality and internal organ health show whether the supplement actually improves the hens’ overall health, not just egg numbers.
This study has several strengths: it used a large number of hens (1,080), had multiple groups to compare, and measured many different outcomes. The researchers used proper scientific controls and repeated the experiment multiple times to ensure results were reliable. However, the study was conducted in one specific type of chicken breed in controlled farm conditions, so results might differ in other settings or with different chicken breeds.
What the Results Show
Hens that received bile acid supplements laid more eggs overall, and the improvement was strongest in the group receiving 300 mg per kilogram of feed. The eggs from supplemented hens were also better quality—the egg whites were thicker and more gel-like (measured by something called Haugh unit), and the yolks had better color. Importantly, these hens needed less feed to produce each egg, meaning farmers would spend less on feed costs.
The most interesting finding was that 300 mg appeared to be the sweet spot—more wasn’t necessarily better. The group receiving 500 mg showed slightly less improvement than the 300 mg group, suggesting there’s an optimal amount beyond which additional bile acids don’t help as much.
When researchers examined the hens’ reproductive organs under a microscope, they found that bile acid supplementation actually changed the structure of the egg-producing organs in beneficial ways. The tissues lining the oviduct (the tube where eggs form) and uterus became thicker and more developed, which likely explains why egg production improved.
Beyond egg production, the hens that received bile acids digested their food much more efficiently. They absorbed more nutrients from their feed, including proteins and amino acids (the building blocks of protein). Blood tests showed improvements in various health markers, suggesting the supplement improved overall body function. The hens’ intestines also showed better structure and health under microscopic examination, indicating that bile acids helped their digestive systems work better.
Bile acids are known from previous research to help with fat digestion and nutrient absorption in animals. This study confirms those benefits and extends them to show that bile acids can specifically help aging laying hens maintain productivity. The finding that 300 mg is optimal aligns with other nutritional research showing that more of a supplement isn’t always better—there’s usually a sweet spot where benefits peak.
This study was conducted with one specific chicken breed (Hy-Line Brown) in a controlled farm environment, so results might be different with other breeds or in different farming conditions. The study lasted only 35 days, so we don’t know if benefits continue longer or if hens eventually adapt to the supplement. The research doesn’t explain exactly how bile acids improve egg production at the cellular level. Additionally, the study was conducted in 2026, so long-term practical experience with this supplement in real-world farms is still limited.
The Bottom Line
For poultry farmers with aging laying hens, adding 300 mg of bile acids per kilogram of feed appears to be an effective strategy to improve egg production and quality. This recommendation has moderate-to-strong evidence from this controlled study. Farmers should start with this dose rather than higher amounts, as the research shows diminishing returns at 500 mg. Results should be monitored over several weeks to confirm benefits in your specific farm conditions.
Commercial egg producers and small-scale chicken farmers with aging flocks would benefit most from this research. Backyard chicken keepers might also find it useful if they want to extend the productive life of their hens. This research is specifically about laying hens past their peak production years (76+ weeks old), so it may not apply to younger hens or meat chickens. Anyone considering this supplement should consult with a poultry nutritionist to ensure it fits their specific situation.
Based on this 35-day study, farmers should expect to see improvements in egg production and quality within 2-4 weeks of starting the supplement. However, the most pronounced benefits appeared around the 35-day mark, suggesting that consistent use over at least a month is needed to see full results. Long-term effects beyond 35 days are unknown.
Frequently Asked Questions
Can bile acid supplements help older chickens lay more eggs?
Research shows that adding 300 mg of bile acids per kilogram of feed increased egg production in 76-week-old laying hens over a 35-day period. The supplement also improved egg quality and reduced feed costs per egg, making it a practical option for aging flocks.
What is the best dose of bile acids for laying hens?
A 2026 study of 1,080 hens found that 300 mg of bile acids per kilogram of feed produced the best results. Higher doses (500 mg/kg) showed slightly less improvement, suggesting 300 mg is the optimal amount for maximum benefits.
How long does it take to see improvements from bile acid supplements in chickens?
The study measured results over 35 days and found improvements throughout this period. Farmers should expect to see noticeable changes in egg production and quality within 2-4 weeks of starting the supplement at the recommended 300 mg/kg dose.
Do bile acids improve chicken health beyond just egg production?
Yes, the research showed that bile acid supplementation improved nutrient absorption, intestinal health, and reproductive organ structure in aging hens. Blood tests also showed favorable changes in health markers, indicating benefits beyond just egg numbers.
Is bile acid supplementation cost-effective for small chicken farms?
The study showed that supplemented hens needed less feed per egg produced, potentially offsetting supplement costs. However, cost-effectiveness depends on local feed and supplement prices. Small-scale farmers should calculate their specific economics before implementing this strategy.
Want to Apply This Research?
- Track daily egg production numbers and egg quality grades (shell color, yolk color, white thickness) for each flock group. Record the exact amount of bile acid supplement added to feed and the date started. Compare weekly egg production averages before and after supplementation began.
- If using a poultry management app, input the bile acid supplement dose (300 mg/kg) into the feed formulation section. Set weekly reminders to measure and record egg quality metrics. Create a comparison view showing production data from before and after supplementation to visualize improvements.
- Establish a baseline of egg production and quality for 2 weeks before starting the supplement. Then track the same metrics weekly for at least 8 weeks after starting. Monitor feed costs and calculate the cost-per-dozen eggs to determine if improved production justifies the supplement expense. If using the app, set alerts if production drops below expected levels, which might indicate the supplement needs adjustment or that other factors are affecting the flock.
This research was conducted on laying hens in controlled farm conditions and may not apply to all chicken breeds, farm environments, or management practices. Results are based on a 35-day study, and long-term effects beyond this period are unknown. Before implementing bile acid supplementation in your flock, consult with a poultry veterinarian or nutritionist to ensure it’s appropriate for your specific situation, as individual results may vary. This information is for educational purposes and should not replace professional agricultural or veterinary advice. Always follow product label instructions and local regulations when using feed supplements.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.