Research shows that replacing 3% of regular soybean meal with enzymolytic soybean meal (processed soybean meal treated with enzymes) significantly improves broiler chicken growth and digestive health. According to Gram Research analysis of a 42-day study with 400 chickens, those fed the 3% replacement diet grew faster, converted feed to body weight more efficiently during the final three weeks, and developed healthier intestinal structures with beneficial gut bacteria that produce propionate, a compound that supports digestive health.
Researchers tested a new type of processed soybean meal called enzymolytic soybean meal (ESBM) in chicken feed to see if it could improve how well chickens grow. They fed 400 baby chickens different amounts of this special soybean meal for 42 days and measured their growth, digestive health, and gut bacteria. According to Gram Research analysis, chickens that ate a diet with 3% ESBM grew faster, converted feed to body weight more efficiently, and had healthier intestines compared to chickens eating regular soybean meal. The treated chickens also developed beneficial gut bacteria that produce helpful compounds called short-chain fatty acids.
Key Statistics
A 42-day study of 400 broiler chickens published in Poultry Science in 2026 found that replacing 3% of soybean meal with enzymolytic soybean meal significantly increased average daily weight gain and reduced feed conversion ratio during the final three weeks compared to control birds.
Research with 400 broiler chickens showed that 3% enzymolytic soybean meal replacement increased duodenal villus height and the villus-height-to-crypt-depth ratio, structural improvements that enhance nutrient absorption in the small intestine.
A 2026 study of 400 broilers found that enzymolytic soybean meal at 3% replacement increased the relative abundance of beneficial Alistipes bacteria in the cecum, which correlated positively with propionate concentration, a short-chain fatty acid that supports intestinal health.
In a 400-bird broiler study, the 4% enzymolytic soybean meal replacement group showed significantly higher cecal propionate concentration compared to control birds, indicating enhanced production of this beneficial metabolite.
The Quick Take
- What they studied: Whether replacing regular soybean meal with a specially processed version (enzymolytic soybean meal) in chicken feed could improve chicken growth, digestive health, and gut bacteria.
- Who participated: 400 one-day-old male broiler chickens (the type raised for meat) divided into 5 groups. One group ate regular feed, and four groups ate feed with increasing amounts of the special soybean meal (1%, 2%, 3%, or 4% replacement).
- Key finding: Chickens eating feed with 3% enzymolytic soybean meal grew significantly faster and needed less feed to gain weight compared to the control group during the final three weeks of the study (P less than 0.05, meaning this result was very unlikely to happen by chance).
- What it means for you: If you raise chickens for meat or eggs, using this special soybean meal could help your birds grow better and more efficiently, potentially saving money on feed costs. However, this research is specific to broiler chickens and may not apply to other animals or poultry types.
The Research Details
Researchers conducted a 42-day experiment with 400 baby chickens divided equally into 5 groups with 8 replicates of 10 birds each. One group served as the control and received standard corn and soybean meal feed. The other four groups received feed where regular soybean meal was replaced with enzymolytic soybean meal at increasing levels: 1%, 2%, 3%, or 4%. The scientists measured how fast the chickens grew, how efficiently they converted feed into body weight, the structure of their intestines under a microscope, the types of bacteria in their cecum (part of the large intestine), and the levels of short-chain fatty acids (beneficial compounds produced by gut bacteria). This design allowed researchers to test whether more of the special ingredient was better or if there was an optimal amount.
This research approach is important because it tests a practical, real-world application in actual chickens rather than in laboratory conditions. By measuring multiple outcomes (growth, intestinal health, gut bacteria, and beneficial compounds), the researchers could understand how the special soybean meal affects the whole digestive system, not just one aspect. The use of multiple groups with different amounts of the ingredient helped identify the best dose, which is crucial for farmers deciding whether to use this product.
This study has several strengths: it used a large sample size (400 birds), included multiple treatment groups to identify the optimal dose, measured multiple relevant outcomes, and used statistical analysis to confirm results were not due to chance. The study was published in Poultry Science, a peer-reviewed journal. However, the study focused only on male broiler chickens, so results may not apply to other types of poultry or different farming conditions. The researchers did not report some details about how the enzymolytic soybean meal was processed, which could affect reproducibility.
What the Results Show
The most important finding was that chickens receiving 3% enzymolytic soybean meal (called the T3 group) showed significantly better growth performance during the final three weeks of the study compared to control chickens. These chickens had higher average daily weight gain and a lower feed conversion ratio, meaning they needed less feed to gain each pound of body weight. This is economically important for chicken farmers because feed is typically the largest expense in raising chickens. The intestinal structure of these chickens also improved: they had taller finger-like projections called villi in their small intestines and a better ratio of villus height to crypt depth. These structural improvements are important because taller villi increase the surface area available for nutrient absorption, helping chickens get more nutrition from their food.
Chickens in the T3 group also showed changes in their gut bacteria composition, specifically an increase in a beneficial bacteria called Alistipes. In the group receiving 4% enzymolytic soybean meal (T4 group), researchers found significantly higher levels of propionate, a short-chain fatty acid that provides energy to intestinal cells and has anti-inflammatory properties. The study revealed a positive correlation between the amount of Alistipes bacteria and propionate levels, suggesting these bacteria may produce this beneficial compound. These microbial changes are important because a healthy, diverse gut microbiota supports overall digestive health and immune function in chickens.
This research builds on previous studies showing that enzyme-treated feed ingredients can improve nutrient availability and digestive health in poultry. Earlier research suggested that processing soybean meal with enzymes could break down complex compounds that normally reduce nutrient absorption. This study confirms those findings and goes further by showing specific improvements in intestinal structure and beneficial bacteria. The finding that 3% replacement appears optimal aligns with other research suggesting that moderate amounts of novel feed ingredients often work better than high levels, possibly because very high levels may disrupt normal digestive function.
The study only tested male broiler chickens, so results may not apply to female chickens, laying hens, or other poultry species. The experiment lasted 42 days, which is the typical lifespan for meat chickens, but we don’t know if benefits would continue longer or if there might be long-term effects. The study measured outcomes at the end of the experiment but didn’t track changes over time, so we don’t know exactly when improvements began. The research was conducted in a controlled laboratory setting, so results might differ in real farm conditions with variations in temperature, humidity, and management. Finally, the study didn’t report the cost of enzymolytic soybean meal compared to regular soybean meal, which is crucial for farmers deciding whether to use it.
The Bottom Line
For poultry farmers raising broiler chickens, replacing 3% of regular soybean meal with enzymolytic soybean meal appears to be a beneficial strategy with strong evidence from this controlled study. This level of replacement improved growth rate, feed efficiency, and digestive health without apparent negative effects. Farmers should consider testing this ingredient on a small scale first to evaluate cost-effectiveness in their specific operation. The recommendation is moderate confidence because the study was well-designed but limited to one chicken type and one controlled environment.
This research is most relevant to commercial broiler chicken farmers and feed manufacturers looking to improve chicken growth and feed efficiency. It may also interest poultry nutritionists and veterinarians who advise farmers. The findings are less directly applicable to backyard chicken keepers, egg-laying operations, or other livestock producers, though some principles about enzyme-treated ingredients may be relevant. Consumers of chicken meat might care indirectly if this ingredient becomes widely adopted and reduces production costs.
Based on this study, improvements in growth performance became apparent during the final three weeks of the 42-day experiment, suggesting that benefits develop gradually over several weeks rather than immediately. Farmers would likely see measurable improvements in feed conversion ratio and weight gain within 3 to 4 weeks of switching to feed containing 3% enzymolytic soybean meal. However, the optimal time to start this feed would be early in the chicken’s life to maximize total growth benefits.
Frequently Asked Questions
What is enzymolytic soybean meal and how is it different from regular soybean meal?
Enzymolytic soybean meal is regular soybean meal that has been treated with enzymes to break down complex compounds that normally reduce nutrient absorption. This processing makes nutrients more available for chickens to absorb and digest, improving feed efficiency and growth.
How much enzymolytic soybean meal should I add to my chicken feed?
Research indicates that replacing 3% of regular soybean meal with enzymolytic soybean meal provides optimal benefits for broiler chickens. This level improved growth performance and digestive health without negative effects. Higher levels (4%) showed some benefits but weren’t superior to the 3% level.
When will I see improvements in my flock if I switch to this ingredient?
Based on this study, improvements in growth rate and feed efficiency become noticeable during the final three weeks of the chicken’s life. For a typical 42-day broiler cycle, you’d expect to see measurable benefits starting around day 22 to 28 after introducing the new feed.
Does enzymolytic soybean meal work for all types of chickens?
This research specifically tested male broiler chickens raised for meat. Results may not apply to laying hens, breeding stock, or other poultry species. Farmers raising different types of chickens should seek research specific to their birds before making feed changes.
What are short-chain fatty acids and why do they matter in chicken feed?
Short-chain fatty acids like propionate are compounds produced by beneficial gut bacteria. They provide energy to intestinal cells, support immune function, and have anti-inflammatory properties. Higher levels indicate a healthier digestive system and better overall bird health.
Want to Apply This Research?
- If you raise chickens, track weekly weight gain and feed consumption for each flock to calculate feed conversion ratio (pounds of feed needed per pound of weight gain). Compare these metrics before and after introducing enzymolytic soybean meal to your feed to measure real-world impact on your operation.
- Switch your chicken feed supplier to one offering enzymolytic soybean meal, or request that your current supplier include 3% enzymolytic soybean meal in your broiler feed formulation. Start with one batch to test results before committing to larger quantities.
- Establish a baseline of your current feed conversion ratio and average daily weight gain over 2 to 3 flocks. After introducing the new feed, track these same metrics for 3 to 4 flocks to determine if you’re seeing the 3% to 5% improvement in efficiency that this research suggests is possible. Also monitor for any changes in bird health, mortality, or feed intake that might indicate the ingredient isn’t working well in your specific conditions.
This research applies specifically to broiler chickens and may not be relevant to other poultry species or production systems. The study was conducted in controlled laboratory conditions and results may vary in real-world farm settings. Before making changes to your chicken feed, consult with a poultry nutritionist or veterinarian familiar with your specific operation. This information is for educational purposes and should not replace professional agricultural or veterinary advice. Individual results may vary based on factors including feed quality, farm management practices, environmental conditions, and bird genetics.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.