A flaxseed oil-based supplement called Persialin improved sperm quality in aging roosters, increasing sperm membrane integrity from 83.8% to 88.4% and sperm functionality from 38.9% to 48.2% in a 2026 study of 32 birds. According to Gram Research analysis, the supplement also changed beneficial fatty acids in testicular tissue and affected hormone levels, though actual fertility improvements were not measured.
Researchers tested a dietary supplement called Persialin, made from flaxseed oil and calcium, on older roosters to see if it could improve their reproductive health. The study found that roosters receiving the supplement had better sperm quality, with improvements in sperm membrane integrity and overall function. The supplement also changed the types of fats in the roosters’ testicles and affected hormone levels. While the supplement didn’t change body weight or basic sperm production, it showed promise for maintaining reproductive performance as roosters age, though more research is needed to confirm these benefits translate to actual fertility improvements.
Key Statistics
A 2026 study of 32 aging roosters found that dietary Persialin supplement increased sperm plasma membrane integrity from 83.8% to 88.4% and sperm functionality from 38.9% to 48.2% over six weeks.
Roosters receiving the flaxseed oil-based supplement showed increased docosahexaenoic acid levels in testicular tissue and decreased arachidonic acid, with testosterone peaking at the lowest supplement dose of 1.4%.
The supplement reduced apoptosis-related gene expression in testicular tissue, with the highest dose of Persialin (4.2%) most effectively decreasing Bax expression and the Bax/Bcl2 ratio in aging roosters.
The Quick Take
- What they studied: Whether a flaxseed oil-based supplement called Persialin could improve sperm quality and reproductive health in older roosters.
- Who participated: Thirty-two roosters that were 70 weeks old (equivalent to elderly birds). They were divided into four groups: one control group receiving regular feed, and three groups receiving different amounts of the Persialin supplement mixed into their feed for six weeks.
- Key finding: Roosters given the supplement had significantly better sperm quality. Sperm membrane integrity improved from 83.8% to 88.4%, and sperm functionality jumped from 38.9% to 48.2%. The supplement also increased beneficial fatty acids in testicular tissue and affected testosterone levels.
- What it means for you: This research suggests that dietary supplements containing flaxseed oil might help maintain reproductive health in aging animals. However, this study was conducted in roosters, not humans, so results may not directly apply to people. Anyone considering similar supplements should consult with a healthcare provider first.
The Research Details
Researchers divided 32 older roosters into four equal groups of eight birds each. One group received normal feed as a control, while the other three groups received the same feed mixed with different amounts of Persialin supplement (1.4%, 2.8%, or 4.2% by weight). All birds ate their assigned diet for six weeks. The researchers collected sperm samples at three different time points (weeks 4, 7, and 10 of the study) and blood samples at the same times. At the end of the study, they also removed and examined testicular tissue from all birds. They analyzed the sperm for quality markers, examined the testicular tissue under a microscope, measured hormone levels in the blood, and identified specific genes related to cell death in the testicular tissue.
This research approach matters because it allowed scientists to track changes over time in multiple reproductive measures. By collecting samples at different points rather than just at the end, researchers could see how the supplement affected the roosters as they aged. Examining both sperm quality and the actual tissue structure of the testicles provided a complete picture of reproductive health. Testing for specific genes related to cell death helped explain the biological mechanisms behind any improvements observed.
The study used a randomized design, meaning roosters were randomly assigned to groups, which reduces bias. The researchers measured multiple outcomes rather than relying on a single marker, which strengthens confidence in the findings. However, the study included only 32 birds total, which is a relatively small sample size. The study was conducted in roosters, not humans, so results may not directly apply to people. The researchers did not measure actual fertility or breeding success, only markers of reproductive health. The study lasted only six weeks, so long-term effects remain unknown.
What the Results Show
The supplement improved sperm quality in several important ways. Sperm plasma membrane integrity, which measures how well the outer coating of sperm cells is preserved, increased from 83.8% in control birds to 88.4% in supplemented birds. Sperm functionality, a measure of how well sperm can perform their biological role, improved even more dramatically, rising from 38.9% to 48.2%. These improvements followed a linear dose-response pattern, meaning higher doses of the supplement produced better results. Interestingly, the supplement did not affect body weight, the volume of ejaculate, or basic sperm motility, suggesting it specifically targeted sperm quality rather than overall reproductive output. The supplement also changed the composition of fatty acids in testicular tissue, increasing beneficial omega-3 fatty acids like docosahexaenoic acid while decreasing arachidonic acid, a less favorable fatty acid for reproductive health.
The supplement affected testosterone levels in a dose-dependent manner, with the middle dose (2.8%) producing the largest seminiferous tubules, which are the structures in testicles that produce sperm. Testosterone levels peaked at the lowest supplement dose (1.4%), increasing from 3.38 to 3.95 nanograms per milliliter of blood. The supplement also reduced expression of genes related to cell death in testicular tissue, particularly decreasing the Bax gene and the ratio of Bax to Bcl2. This suggests the supplement may protect testicular cells from dying prematurely. These secondary findings indicate that the supplement works through multiple biological pathways to support reproductive health.
This study builds on existing research showing that omega-3 fatty acids and flaxseed oil can support reproductive health in various species. Previous research has demonstrated that dietary fats influence sperm quality and testicular function, but this appears to be one of the first studies examining a specific flaxseed oil-based supplement in aging roosters. The findings align with broader research suggesting that nutritional interventions can help maintain reproductive performance during aging. However, most previous studies have focused on younger animals or humans, making this research particularly relevant for understanding how aging affects reproductive health and how supplements might help.
The study was conducted only in roosters, so results may not apply to humans or other species. The sample size was small (32 birds total), which limits the strength of conclusions. The study lasted only six weeks, so long-term effects and safety are unknown. The researchers did not measure actual fertility or breeding success, only markers of reproductive health. It remains unclear whether the improvements in sperm quality would actually result in better breeding outcomes. The study did not include a comparison with other supplements or treatments. The mechanism by which the supplement works is not fully understood, though the changes in fatty acids and gene expression provide clues.
The Bottom Line
Based on this research, Persialin supplement at a dose of 2.8% appears most effective for improving sperm membrane quality and testicular structure in aging roosters. The 1.4% dose was most effective for increasing testosterone. These findings suggest potential benefits for maintaining reproductive health in aging birds, though confidence in these recommendations is moderate because the study was small and conducted only in roosters. More research is needed before drawing firm conclusions about human applications or other species.
This research is most relevant to poultry farmers and breeders who work with aging roosters and want to maintain reproductive performance. Veterinarians specializing in poultry may find these results useful for recommending nutritional interventions. Researchers studying aging and reproductive health may find this work valuable for understanding how dietary supplements affect reproductive tissues. The general public should note that this research was conducted in birds, not humans, so direct application to human health is not yet established.
In this study, improvements in sperm quality were measurable within four weeks of starting the supplement. Testosterone levels and testicular tissue changes were observed after six weeks. Realistic expectations would be to see changes in reproductive markers within 4 to 6 weeks if similar supplements were used in other species, though individual variation would likely occur. Long-term effects beyond six weeks remain unknown.
Frequently Asked Questions
Can flaxseed oil supplements improve sperm quality in older males?
Research in aging roosters shows flaxseed oil-based supplements can improve sperm membrane integrity and functionality. However, this study was conducted in birds, not humans, so results may not directly apply to people. Consult a healthcare provider before starting any supplement.
What dose of flaxseed supplement is most effective for reproductive health?
In the rooster study, a 2.8% dose of Persialin produced the best improvements in sperm membrane quality and testicular structure, while a 1.4% dose most effectively increased testosterone levels. Optimal doses for humans remain unknown.
How long does it take to see benefits from flaxseed oil supplements?
In this study, improvements in sperm quality were measurable within four weeks, with more pronounced changes by six weeks. Individual results vary, and long-term effects beyond six weeks have not been studied.
Does flaxseed oil supplement affect body weight or overall health?
In the rooster study, the supplement did not affect body weight or basic reproductive measures like ejaculate volume. It specifically improved sperm quality markers and testicular tissue composition without causing weight changes.
What fatty acids does flaxseed oil add to the body?
Flaxseed oil increased beneficial omega-3 fatty acids like docosahexaenoic acid and oleic acid in testicular tissue while decreasing arachidonic acid. These changes in fatty acid composition may support reproductive health.
Want to Apply This Research?
- Users could track supplement intake by logging daily doses of flaxseed oil-based products and noting the specific amount in grams or percentage. Pair this with periodic measurements of energy levels or general wellness markers to monitor overall effects.
- Users interested in reproductive health could set a daily reminder to take a flaxseed oil supplement at a consistent time, such as with breakfast. They could also track dietary sources of omega-3 fatty acids from foods like flaxseeds, walnuts, and fatty fish to ensure adequate intake from multiple sources.
- Over a 6 to 12 week period, users could monitor general health markers such as energy levels, mood, and any changes in physical performance. For those specifically concerned with reproductive health, working with a healthcare provider to track relevant biomarkers would provide objective data on supplement effectiveness.
This research was conducted in roosters, not humans. Results may not apply directly to human reproductive health. Flaxseed oil supplements are generally considered safe but may interact with certain medications or medical conditions. Anyone considering flaxseed oil or other reproductive health supplements should consult with a qualified healthcare provider before starting. This article is for informational purposes only and should not replace professional medical advice. The study measured sperm quality markers but did not confirm actual fertility improvements. Long-term safety and effectiveness in humans remain unknown.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.