Scientists studied what makes some chickens grow faster than others by looking at their genes, gut bacteria, and immune systems. They found that chickens with faster growth had less inflammation (swelling and irritation) in their small intestines and better protection against harmful substances. The study examined 72 young chickens fed special diets with probiotics or postbiotics—substances that help gut health. The results suggest that keeping a chicken’s intestines healthy and less inflamed could be a key to helping them grow bigger and stronger in less time.
The Quick Take
- What they studied: What differences in genes, gut bacteria, and immune systems are connected to chickens that grow faster and heavier
- Who participated: 72 male Ross 308 broiler chickens that were 35 days old, raised in normal farm conditions and fed diets with added probiotics or postbiotics
- Key finding: Chickens that grew bigger had less inflammation in their small intestines and stronger natural defenses against damage, especially in the part of the intestine called the jejunum
- What it means for you: For chicken farmers, this suggests that managing gut health and reducing intestinal inflammation could be an important way to help chickens grow faster. However, this research was done in chickens, not humans, so the direct applications are for poultry farming.
The Research Details
Researchers studied 72 young chickens and looked at multiple biological systems at the same time—a approach called ‘multi-omics.’ They examined genes in different tissues (blood, small intestine, and immune tissue), the bacteria living in the chickens’ guts, chemical compounds in the digestive system, and blood markers of health and immunity. The chickens were divided into groups that received different types of feed supplements: some got probiotics (live helpful bacteria), some got postbiotics (beneficial substances from bacteria), and some got these with or without carriers. By comparing chickens that grew quickly with those that grew slowly, the scientists could identify which biological systems were most connected to faster growth.
This multi-system approach is like being a detective who looks at many different clues instead of just one. Rather than studying only genes or only gut bacteria, the researchers examined everything together to get a complete picture. This helps them understand how different body systems work together to affect growth.
Using multiple types of biological data at once is important because it shows how different systems in the body communicate and work together. If researchers only looked at genes, they might miss important information about gut bacteria. If they only looked at bacteria, they might miss what the immune system is doing. By studying everything together, they could identify that intestinal inflammation is a key factor connected to slower growth, which wouldn’t have been as clear from studying just one system.
This study has several strengths: it used a large number of chickens (72 for detailed analysis), examined multiple biological systems, and was conducted under real farm conditions rather than artificial laboratory settings. However, the study was observational—meaning researchers watched what happened naturally rather than randomly assigning chickens to different treatments to test cause and effect. This means we can see that inflammation and growth are connected, but we can’t be completely certain that reducing inflammation will definitely cause faster growth. The study was published in a peer-reviewed scientific journal, meaning other experts reviewed it before publication.
What the Results Show
The most important finding was that the genes expressed in the jejunum (the first part of the small intestine) showed the strongest connection to how fast chickens grew. Chickens that grew slower had more activity in genes related to inflammation—the body’s response to irritation or damage. These inflammation-related genes were involved in several pathways, including ones that help fight infections and respond to harmful substances.
In contrast, chickens that grew faster showed the opposite pattern: they had less inflammation-related gene activity in their small intestines and more activity in genes related to antioxidant defenses—the body’s natural protection against damage from harmful molecules. This suggests that a less inflamed intestine is associated with better growth.
In the caecal tonsil tissue (immune tissue in the large intestine), chickens with faster growth showed more activity in genes related to immune function and communication between immune cells. Interestingly, the gut bacteria in these faster-growing chickens didn’t show major differences compared to slower-growing chickens, suggesting that the genes and immune system matter more than the specific bacteria present.
The study found that blood markers of health and immune function showed some differences between fast-growing and slow-growing chickens, but these were less strongly connected to growth than the intestinal gene patterns. The probiotics and postbiotics in the feed had some effects on the chickens’ biology, but the connection between these supplements and growth wasn’t as strong as the connection between intestinal inflammation and growth. This suggests that while feed supplements may help, the underlying intestinal health is what really matters for growth.
Previous research has shown that gut health affects growth in chickens, but this study is more comprehensive because it looked at multiple biological systems at once. Earlier studies might have focused only on bacteria or only on immune function. This research confirms that inflammation in the small intestine is important for growth and adds new information by showing that antioxidant defenses are also connected to faster growth. The findings align with general knowledge that healthy guts support better growth in animals.
This study has several important limitations. First, it was observational rather than experimental, so we can see that inflammation and growth are connected, but we can’t prove that reducing inflammation will definitely cause faster growth. Second, the study only looked at chickens at one age (35 days old), so we don’t know if these patterns hold true at other ages. Third, the study was done in chickens, not humans or other animals, so the findings may not apply to other species. Fourth, while 72 chickens is a reasonable number for detailed genetic analysis, it’s a relatively small group for making broad conclusions. Finally, the study measured many different biological factors, which increases the chance of finding connections by random chance rather than real relationships.
The Bottom Line
For poultry farmers: Consider management practices that reduce intestinal inflammation in broiler chickens, such as optimizing diet quality, managing stress, and maintaining good housing conditions. The use of probiotics or postbiotics may help, though this study suggests they’re less important than overall intestinal health. These recommendations have moderate confidence because the study shows strong associations but doesn’t prove cause and effect. For researchers: This study suggests that targeting intestinal inflammation and antioxidant defenses could be a promising approach for improving broiler growth, warranting further experimental studies.
This research is most relevant to poultry farmers and the chicken farming industry, as it provides insights into factors affecting broiler chicken growth. Veterinarians who work with poultry should be aware of these findings. Nutritionists developing chicken feed may find this useful for formulating diets that support gut health. This research is not directly applicable to human nutrition or health, though the general principle that gut health affects overall health is relevant to many fields. People interested in sustainable food production may care about this because improving chicken growth efficiency could reduce resource use.
If farmers implement changes based on these findings, they might expect to see effects on chicken growth within the normal broiler growth period (around 6-7 weeks total). However, since this study shows associations rather than proving cause and effect, the actual timeline for seeing improvements would depend on which specific interventions are used and how well they reduce intestinal inflammation. Changes in gut bacteria might show effects within days to weeks, while changes in gene expression could take similar timeframes.
Want to Apply This Research?
- For poultry farmers using a farm management app: Track intestinal health indicators weekly, including feed conversion ratio (how much feed produces how much growth), visible signs of digestive health in droppings, and any signs of intestinal disease. Compare these metrics between flocks with different management practices to identify which approaches best support gut health.
- Implement a weekly gut health monitoring protocol: assess feed quality and consistency, monitor water quality and availability, track environmental stress factors (temperature, noise, crowding), and document any health issues. Use the app to record these observations and correlate them with growth performance data to identify which management changes have the biggest impact on growth.
- Establish a long-term tracking system that monitors growth performance alongside intestinal health indicators across multiple flocks. Create alerts when growth rates fall below expected levels, and use the app to investigate potential causes related to feed quality, environmental stress, or disease. Over time, this data can help identify which specific management practices most effectively support the intestinal health that this research suggests is crucial for growth.
This research was conducted in broiler chickens and may not apply to other species, including humans. The study shows associations between intestinal inflammation and growth but does not prove that reducing inflammation will definitely improve growth. Poultry farmers should consult with veterinarians and animal nutritionists before making significant changes to feeding or management practices based on this research. This information is for educational purposes and should not replace professional veterinary or nutritional advice. The findings are preliminary and should be confirmed by additional research before being widely implemented.