According to Gram Research analysis, selenium supplementation significantly enhanced donkey milk’s immune and antioxidant properties in a controlled study of 14 donkeys. Selenium-supplemented milk showed increased levels of lactoferrin and immunoglobulins—protective proteins that boost immune function—along with 40-50% greater antioxidant activity compared to unsupplemented milk. Advanced molecular analysis revealed selenium activated multiple biological pathways involved in immune defense and cellular protection, suggesting potential nutritional benefits for consumers.
Researchers discovered that adding selenium to donkeys’ food significantly improves the quality of their milk. The study found that selenium-supplemented donkey milk contained higher levels of protective proteins and stronger antioxidant activity—substances that fight harmful molecules in your body. Scientists used advanced lab techniques to analyze the milk’s composition and found that selenium triggered beneficial changes in key metabolites and proteins. This research suggests that selenium supplementation could make donkey milk an even more nutritious food, potentially offering enhanced immune and antioxidant benefits for people who consume it.
Key Statistics
A 2026 study of 14 lactating donkeys found that dietary selenium supplementation (0.3 mg/kg) significantly increased lactoferrin and immunoglobulin concentrations in milk compared to control animals receiving minimal selenium (0.04 mg/kg).
Selenium-supplemented donkey milk demonstrated substantially enhanced antioxidant activity, with increased 2,2-diphenyl-1-picrylhydrazyl and hydroxyl radical scavenging capacity measured in whey samples from the supplemented group (P < 0.05).
Proteomic analysis of selenium-supplemented donkey milk identified 4 key differentially abundant proteins—ceroplasmin, lipopolysaccharide-binding protein, fatty acid binding protein 4, and interleukin 1 receptor type 1—involved in immune and metabolic signaling pathways.
Metabolomic analysis revealed selenium upregulated niacin and 4-hydroxyphenylpyruvic acid in donkey milk, activating nicotinate and tyrosine metabolism pathways associated with immune function and antioxidant defense.
The Quick Take
- What they studied: Whether adding selenium to donkeys’ diet improves the nutritional quality and protective compounds in their milk
- Who participated: 14 lactating donkeys divided into two groups: one eating normal feed and one eating feed with added selenium for 10 weeks
- Key finding: Donkeys fed selenium-enriched diets produced milk with significantly higher levels of immune-boosting proteins and stronger antioxidant power compared to the control group
- What it means for you: Selenium-supplemented donkey milk may offer enhanced immune and antioxidant benefits, though more human studies are needed to confirm practical health advantages
The Research Details
Scientists divided 14 lactating donkeys into two groups for 10 weeks. One group ate a standard diet with minimal selenium (0.04 mg per kilogram), while the other group received the same diet plus extra selenium from selenium yeast (0.3 mg per kilogram). The researchers then carefully analyzed the milk from both groups using two advanced laboratory techniques: metabolomics (which identifies small chemical compounds) and proteomics (which identifies proteins). This allowed them to see exactly how selenium changed the milk’s composition at a molecular level.
The study design is straightforward and practical—researchers simply changed one variable (selenium intake) and measured the resulting changes in milk quality. By comparing the two groups side-by-side, they could determine whether the differences were actually caused by the selenium supplementation rather than other factors.
This approach is valuable because it shows cause-and-effect relationships in a controlled setting, though the small number of animals means results should be confirmed with larger studies before making broad claims.
Using advanced proteomics and metabolomics techniques allowed researchers to identify exactly which proteins and chemical compounds changed in response to selenium. This level of detail goes beyond simple measurements and reveals the biological mechanisms—the ‘how’ and ‘why’—behind selenium’s effects. Understanding these mechanisms helps scientists predict whether the benefits might apply to other species, including humans.
Strengths: The study used randomized assignment (reducing bias), controlled the diet precisely, and employed cutting-edge analytical techniques. The findings showed statistical significance (P < 0.05), meaning the results are unlikely due to chance. Limitations: Only 14 animals were studied, which is a small sample size. The research was conducted in donkeys, so human benefits remain theoretical. The study lasted only 10 weeks, so long-term effects are unknown. No human consumption trials were conducted to verify practical health benefits.
What the Results Show
Selenium supplementation produced measurable improvements in donkey milk’s protective compounds. Lactoferrin—a protein that fights infections—increased significantly in selenium-supplemented milk. Immunoglobulins (antibodies that boost immune function) also increased substantially. The milk’s antioxidant power, measured by its ability to neutralize harmful free radicals, improved significantly in both tested methods (DPPH and hydroxyl radical scavenging).
Metabolomic analysis revealed that selenium triggered changes in important metabolic pathways. Specifically, selenium upregulated niacin and 4-hydroxyphenylpyruvic acid, compounds involved in energy metabolism and protein processing. These changes suggest selenium influences fundamental biochemical processes that support immune and antioxidant functions.
Proteomic analysis identified several key proteins that changed in response to selenium, including ceroplasmin (which manages iron), lipopolysaccharide-binding protein (which detects bacterial threats), and fatty acid binding protein 4 (which regulates metabolism). These proteins participate in signaling pathways that control inflammation and cellular defense mechanisms.
Together, these findings paint a picture of selenium working at multiple biological levels—boosting immune proteins, enhancing antioxidant capacity, and activating protective metabolic pathways.
The research identified specific signaling pathways activated by selenium supplementation, including ferroptosis (a type of cell death that prevents damage), NF-kappa B signaling (which controls immune responses), and PPAR signaling (which regulates metabolism and inflammation). These pathways are important because they’re involved in how the body fights infection and manages oxidative stress. The fact that selenium influenced multiple pathways suggests its benefits are comprehensive rather than limited to a single mechanism.
This research builds on existing knowledge that selenium is essential for immune function and antioxidant defense in mammals. Previous studies have shown selenium’s importance in human nutrition, but this is among the first to comprehensively map how selenium supplementation changes milk composition using modern proteomics and metabolomics. The findings align with broader research showing that dietary interventions can enhance the nutritional profile of animal products, similar to how omega-3 enriched eggs are produced by feeding hens special diets.
The study involved only 14 donkeys, which is a small sample size that may not represent all donkeys or predict effects in humans. The 10-week duration is relatively short, so long-term effects of selenium supplementation remain unknown. The research measured changes in milk composition but did not test whether humans consuming this milk would actually experience the predicted immune or antioxidant benefits. Donkey milk is not widely consumed in many countries, limiting the practical applicability for most people. The study did not examine potential negative effects of long-term selenium supplementation or optimal dosage levels.
The Bottom Line
Based on this research, selenium supplementation appears to enhance the nutritional quality of donkey milk (moderate confidence). However, recommendations for human consumption should await studies directly testing health outcomes in people who drink selenium-enriched donkey milk. If you consume donkey milk, sourcing from animals receiving adequate selenium may offer theoretical benefits, though this should not replace established dietary practices.
This research is most relevant to: donkey dairy producers seeking to improve milk quality, consumers of donkey milk products (particularly in regions where it’s traditional), and nutritional scientists studying how to enhance animal product quality. It’s less immediately relevant to people who don’t consume donkey milk. The findings may eventually inform strategies for enhancing other animal milks (cow, goat, sheep) through dietary interventions.
If the findings apply to humans, benefits would likely develop gradually over weeks to months as selenium accumulates in the body and influences immune and antioxidant systems. However, no human studies have yet measured the timeline for experiencing benefits from consuming selenium-enriched donkey milk.
Frequently Asked Questions
Does selenium supplementation actually improve milk quality?
Yes, according to this 2026 research, selenium supplementation significantly increased protective immune proteins (lactoferrin and immunoglobulins) and antioxidant activity in donkey milk. However, human studies are needed to confirm whether these changes translate to actual health benefits for people drinking the milk.
How much selenium do donkeys need to improve their milk?
In this study, donkeys receiving 0.3 mg of selenium per kilogram of feed showed significant improvements compared to those receiving only 0.04 mg/kg. However, optimal dosage for different donkey breeds and production goals requires further research.
Can I get these benefits from regular cow’s milk instead?
This study specifically examined donkey milk, so direct comparisons aren’t available. However, similar selenium supplementation strategies might work for cow, goat, or sheep milk. Consult with dairy producers about selenium-enriched options in your region.
What are antioxidants and why do they matter?
Antioxidants are molecules that neutralize harmful free radicals—unstable compounds that damage cells and contribute to aging and disease. Enhanced antioxidant activity in milk could theoretically provide additional protection against cellular damage, though human studies are needed to confirm benefits.
Is donkey milk safe for everyone to drink?
Donkey milk is generally safe for most people and is hypoallergenic compared to cow’s milk, making it suitable for those with dairy sensitivities. However, consult your doctor before consuming it regularly, especially if you have selenium sensitivity or take medications that interact with selenium.
Want to Apply This Research?
- If tracking donkey milk consumption, log weekly intake amount (cups or milliliters) and note any changes in energy levels, immune health (frequency of colds/infections), or skin condition over 8-12 weeks
- For users interested in antioxidant-rich foods, add donkey milk products to their weekly shopping list and track consumption patterns alongside other selenium sources (Brazil nuts, eggs, whole grains) to ensure adequate intake
- Create a 12-week tracking protocol measuring subjective immune markers (illness frequency, recovery time) and energy levels, while maintaining a food diary documenting all selenium sources to correlate intake with wellness metrics
This research demonstrates changes in donkey milk composition following selenium supplementation but has not been tested in humans. The study involved only 14 animals over 10 weeks, so results should be considered preliminary. Selenium supplementation can be toxic at high doses—consult a healthcare provider before significantly increasing selenium intake or giving selenium-supplemented products to children. This article is for informational purposes and should not replace professional medical advice. If you have concerns about selenium intake or immune health, speak with your doctor or registered dietitian.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.