Researchers tested whether adding a special type of algae to cow feed could improve the nutritional quality of milk. They gave 30 dairy cows either regular feed or feed with algae powder—some coated to survive digestion better than others. The coated algae powder worked best, increasing healthy omega-3 fatty acids (specifically DHA) in the milk without reducing how much milk the cows produced. This matters because DHA is important for brain development in babies and young children. The study shows that what cows eat directly affects the nutrition in their milk.

The Quick Take

  • What they studied: Can adding algae powder to cow feed increase healthy omega-3 fatty acids (called DHA) in milk without hurting milk production?
  • Who participated: 30 Holstein dairy cows in the middle of their milk-producing cycle, divided into three equal groups of 10 cows each
  • Key finding: Coated algae powder increased DHA in milk by nearly 5 times compared to regular feed, with the best results appearing by day 21 of supplementation. The coated version worked much better (11.82% transfer rate) than the uncoated version (2.36% transfer rate).
  • What it means for you: If you drink milk from cows fed this algae supplement, you may get more DHA—a nutrient important for brain health. This is especially meaningful for parents of young children. However, this is early research, and more studies are needed to confirm benefits in actual milk products available in stores.

The Research Details

Scientists divided 30 cows into three groups: one ate regular feed (control), one ate feed with uncoated algae powder, and one ate feed with specially coated algae powder. The coating helps the algae survive the cow’s digestive system instead of being broken down immediately. Each group had 10 cows. The study lasted 42 days total: 14 days to let cows adjust, 21 days of the actual test, and 7 days after stopping the supplement to see what happened.

The researchers measured milk production, the types of fats in the milk and in the cows’ blood, and how much DHA actually made it into the milk. They took samples on different days to track changes over time. This approach allowed them to see not just the final result, but how the effect developed day by day.

By testing the coated versus uncoated versions, researchers could figure out which form works better. The coating is important because it protects the algae from being destroyed in the cow’s stomach, allowing more of the healthy omega-3s to reach the milk. This study design helps explain why one version worked so much better than the other.

This is a controlled experiment with a reasonable sample size (30 cows) and a clear comparison between groups. The researchers measured multiple outcomes and tracked changes over time, which strengthens the findings. However, the study was relatively short (3 weeks of actual testing), and it only tested one type of algae supplement. The results are promising but represent early-stage research that would benefit from larger, longer studies.

What the Results Show

The coated algae powder significantly increased DHA in milk compared to both the control group and the uncoated algae group. By day 21, the coated group had nearly 5 times more DHA in their milk than the control group. Interestingly, the effect wasn’t immediate—it built up over the three weeks, reaching peak levels by day 21.

The uncoated algae powder also increased DHA, but much less effectively than the coated version. This makes sense because the coating protects the algae from being broken down in the cow’s stomach. The researchers found that the coated version transferred about 11.82% of the algae’s DHA into the milk, while the uncoated version only transferred about 2.36%—roughly five times less effective.

Importantly, neither supplement reduced milk production. The cows still produced the same amount of milk whether they received the algae or not. This is crucial because it means farmers could use this supplement without losing money on reduced milk output.

When the researchers stopped giving the supplement, DHA levels in the milk gradually decreased over the next week, but the coated algae group still maintained higher levels than the other groups even after stopping.

The study also measured fatty acids in the cows’ blood. The coated algae group showed higher levels of DHA and other omega-3 fatty acids in their blood compared to the other groups, especially by day 14 and day 21. This suggests the supplement was being absorbed and used by the cows’ bodies. The uncoated version also increased blood DHA, but less dramatically. Additionally, the coated algae temporarily reduced milk fat concentration in the first two weeks, but this returned to normal by day 21, suggesting the effect was temporary and not harmful.

This research builds on earlier studies showing that algae can be a source of DHA for dairy cows. Previous research suggested that coating or protecting supplements could help them survive digestion better. This study confirms that idea and shows it works well in practice. The dramatic difference between coated and uncoated versions (5-fold difference) is more impressive than some earlier research suggested, indicating that the coating technology may be more effective than previously thought.

The study only lasted 21 days of actual testing, which is relatively short. Longer studies would show whether the benefits continue or change over time. The study included only 30 cows, all of the same breed (Holstein). Results might be different with other cow breeds or in different environments. The research was done in a controlled laboratory setting, not on actual farms, so real-world results might vary. Finally, the study measured DHA in milk but didn’t test whether babies or children who drank this milk actually absorbed and benefited from the extra DHA.

The Bottom Line

Based on this research, coated algae supplements appear to be an effective way to increase DHA in cow’s milk (moderate confidence level). The uncoated version is much less effective and probably not worth using. If you’re interested in getting more DHA from dairy products, look for milk from cows supplemented with this type of algae, though such products may not yet be widely available. For parents concerned about their children’s DHA intake, this research suggests a potential future option, but current evidence from eating fish or taking fish oil supplements remains stronger.

Parents of young children (especially infants and toddlers) should care about this research because DHA is important for brain development. Pregnant and breastfeeding women may also be interested since DHA supports fetal brain development. People with heart disease or high triglycerides might benefit from more omega-3s. However, people with fish allergies might find this appealing as an alternative source of DHA. Dairy farmers might care because this could be a way to create premium milk products without reducing milk production.

Based on this study, DHA levels in milk increased gradually over three weeks, reaching peak levels by day 21. If you started drinking milk from supplemented cows, you’d likely notice increased DHA within a few weeks. However, the actual health benefits (like improved brain function) would take much longer to measure—probably months to years—and would require larger studies to confirm.

Want to Apply This Research?

  • Track daily DHA intake in micrograms by logging dairy products consumed. Set a target of 200-300 mg DHA per week and monitor whether milk from algae-supplemented cows helps you reach this goal.
  • If you have young children, search for dairy products labeled as containing algae-derived omega-3s or DHA-enriched milk. Start by replacing one serving of regular milk with DHA-enriched milk daily and track your child’s consumption in the app.
  • Monitor DHA intake weekly by logging all dairy products consumed. Compare intake from regular milk versus DHA-enriched milk. Track any other omega-3 sources (fish, supplements, fortified foods) to get a complete picture of DHA consumption over months.

This research is preliminary and shows promise but is not yet definitive proof that algae-supplemented milk will improve health outcomes in humans. DHA is important for health, but this study only measured DHA levels in milk, not actual health benefits in people who drink it. Before making dietary changes for yourself or your children, especially if you have health conditions or allergies, consult with your doctor or a registered dietitian. This information is for educational purposes and should not replace professional medical advice. Products with these supplements may not yet be widely available in stores.