Researchers studied whether adding bile acids (natural compounds made in the liver) to chicken feed could help breeding hens produce better eggs and healthier chicks. They fed 192 hens different diets over several weeks and found that hens receiving bile acid supplements developed more healthy egg-producing follicles in their ovaries. The supplement also appeared to reduce stress in the hens’ livers and helped baby chicks develop stronger intestines. This research suggests that bile acids might be a natural way to improve egg production and offspring health in poultry farming.

The Quick Take

  • What they studied: Whether adding bile acids (natural liver compounds) to chicken feed could help breeding hens produce more and better quality eggs while also improving the health of their chicks.
  • Who participated: 192 Hy-Line Brown breeder hens (a common egg-laying chicken breed) divided into 4 groups receiving different diets over 13-14 weeks. Each group had 8 separate pens of hens.
  • Key finding: Hens that received bile acid supplements developed significantly more healthy egg follicles (the structures that produce eggs) compared to hens without the supplement. Baby chicks from supplemented mothers also showed better intestinal health and less liver stress.
  • What it means for you: If you raise chickens or care about egg quality, this suggests bile acid supplements could naturally improve egg production. However, this research was done in controlled farm settings, so results may vary in different environments. Talk to a veterinarian before making changes to chicken feed.

The Research Details

Researchers divided 192 breeder hens into 4 equal groups. Two groups ate normal-protein feed (16.42% protein), and two groups ate lower-protein feed (15.35% protein). Within each protein level, one group received bile acid supplements and one didn’t. The hens were studied for about 13-14 weeks (from week 62-75 of their laying cycle). Researchers measured egg follicle development, liver health markers, and intestinal development in the chicks born from these hens.

Bile acids are natural compounds that the liver makes from cholesterol. They normally help digest fats, but research shows they also protect cells from damage and support immune function. The researchers gave increasing doses: 120 mg per kilogram of feed for the first 8 weeks, then 200 mg per kilogram for the final 6 weeks.

This type of study is called a controlled experiment because researchers carefully controlled what each group of hens ate and measured specific outcomes. This design helps show whether the supplement actually caused the improvements observed.

As hens age and lay eggs for longer periods, their ovaries experience stress and inflammation that damages egg-producing structures. This is a real problem in commercial egg production because it reduces both the number and quality of eggs. By testing whether bile acids could reduce this stress, researchers were looking for a natural solution that could improve both farm productivity and animal welfare. Understanding how maternal nutrition affects offspring health is also important for ensuring healthy chicks.

This study has several strengths: it used a large number of animals (192 hens), had multiple treatment groups for comparison, and measured multiple health outcomes (follicle development, liver stress, intestinal health). The study was published in a peer-reviewed journal, meaning other experts reviewed it before publication. However, the study was conducted only in chickens, so we can’t directly apply results to other animals or humans. The researchers don’t specify whether they used blinding (where researchers don’t know which group is which) which could affect results. The study also doesn’t report some important details like exact sample sizes per group or statistical significance levels for all findings.

What the Results Show

Hens receiving bile acid supplements developed more pre-grade white and yellow follicles (the early-stage egg structures) compared to hens without supplements. This suggests the supplement helped promote the development of new eggs. The effect appeared to work by reducing oxidative stress (cellular damage from harmful molecules) and supporting the Hedgehog-GnRH pathway, which is a biological system that controls egg production in hens.

When researchers combined the low-protein diet with bile acid supplements, they saw the best results for reducing liver stress. The hens’ livers showed lower levels of oxidative damage, suggesting the supplement protected their liver cells from harm during the demanding egg-laying period.

Baby chicks born from mothers receiving bile acid supplements showed improved intestinal development and stronger immune function in their guts. This means their digestive systems were better equipped to absorb nutrients and fight off harmful bacteria. These chicks also showed signs of less oxidative stress in their bodies overall.

The low-protein diet combined with bile acid supplements appeared to be more effective than either treatment alone. This suggests that the supplement works better when protein levels are slightly reduced, possibly because the bile acids can focus their protective effects more efficiently. The research also found that the supplement’s benefits extended to the next generation—chicks born from supplemented mothers had better intestinal health even though they didn’t directly receive the supplement themselves.

Previous research has shown that bile acids have antioxidant (protective) and immune-boosting properties in various animals. This study is one of the first to specifically test whether bile acids can help aging breeder hens maintain egg production quality. The findings align with earlier research showing that oxidative stress damages egg-producing structures, and that reducing this stress improves reproduction. The study adds new information by showing that maternal bile acid supplementation can benefit offspring health, which hadn’t been thoroughly studied before.

This research was conducted only in chickens, so we don’t know if similar benefits would occur in other poultry or animals. The study measured outcomes at specific time points but didn’t track long-term effects beyond the 13-14 week study period. The researchers didn’t report whether all hens completed the study or if any became sick, which could affect results. The study also doesn’t explain the exact biological mechanisms (how the supplement works at the cellular level) in complete detail. Additionally, the study was conducted in controlled farm conditions, so results might differ in different climates, housing systems, or with different chicken breeds.

The Bottom Line

For poultry farmers: Consider bile acid supplementation (120-200 mg/kg of feed) as a potential strategy to improve egg production and quality in aging breeder hens, particularly when combined with slightly reduced protein levels. Confidence level: Moderate—this shows promise but needs testing in more varied farm settings. Consult with a poultry veterinarian or nutritionist before implementing changes. For consumers: This research suggests that bile acid supplementation could lead to higher quality eggs and healthier chicks, though more research is needed to confirm benefits across different farming conditions.

Commercial egg producers and breeder farms should pay attention to this research, especially those managing older flocks experiencing declining egg quality. Small-scale chicken keepers might also benefit from understanding how maternal nutrition affects offspring health. This research is less directly relevant to people who don’t raise chickens, though it contributes to understanding how nutrition affects reproduction and offspring development across species.

In the study, improvements in follicle development appeared within 8 weeks of supplementation. Benefits to offspring intestinal health were measurable in chicks born during the supplementation period. If a farmer implemented this strategy, they might expect to see improvements in egg quality within 2-3 months, with continued benefits as long as the supplement is provided. Results would likely plateau after several weeks once the hens’ systems fully adapt to the supplement.

Want to Apply This Research?

  • For poultry farmers using a tracking app: Log weekly egg production numbers, egg quality grades (size, shell strength, yolk color), and any changes in hen health or behavior. Compare these metrics before and after starting bile acid supplementation to measure real-world benefits on your specific farm.
  • If managing a flock: Gradually introduce bile acid supplements to feed according to the dosing schedule (120 mg/kg for 8 weeks, then 200 mg/kg), while simultaneously adjusting protein levels slightly downward. Monitor hens daily for any changes in eating habits, activity level, or health. Record observations in the app to track whether changes match the research findings.
  • Establish baseline measurements of current egg production and quality before starting supplementation. Then track weekly for at least 12 weeks to see if improvements match the research timeline. Monitor offspring chick health and growth if breeding on-farm. Use the app to set reminders for supplement refills and to record any environmental changes (temperature, lighting, stress events) that might affect results.

This research was conducted in chickens and may not apply to other animals or humans. The findings suggest potential benefits but are not definitive proof that bile acid supplementation will work the same way in all farm settings or with all chicken breeds. Before making changes to animal feed or nutrition, consult with a veterinarian or animal nutritionist familiar with your specific situation. This research should not replace professional veterinary advice. Results may vary based on factors like climate, housing, breed, and overall farm management practices not controlled in this study.