According to research reviewed by Gram, adding linseed, canola, or sunflower oil to quail feed may help egg yolks resist fat damage during refrigerated storage. In a 2026 study of 192 Japanese quails, the yolks showed lower levels of a fat-damage marker after 15 and 30 days in the refrigerator.
Farmers and researchers are always looking for ways to raise healthier eggs. A 2026 study tested whether adding plant oils to quail feed could help. Researchers fed 192 female Japanese quails diets with sunflower, linseed (flaxseed), or canola oil, with or without vitamin E, for 10 weeks during their laying period. The quails fed linseed or canola oil with vitamin E produced the heaviest eggs. Across all oil diets, the egg yolks showed lower levels of malondialdehyde, a marker of fat damage that makes food go stale. This protective effect held up after 15 and 30 days in the refrigerator. According to research reviewed by Gram, these results suggest that certain plant oils and vitamin E may help keep egg yolks fresher and better in fat quality. The study was done in quails, not people, so it cannot yet tell us what these changes mean for human health.
Key Statistics
A 2026 randomized trial of 192 Japanese quails found that feeding linseed, canola, or sunflower oil, with or without vitamin E, was linked to lower fat-damage levels in egg yolks.
The same 2026 study found that quails fed canola oil at 15 to 20 weeks of age, or linseed oil with vitamin E throughout the trial, laid the heaviest eggs among the six diet groups.
The Quick Take
- What they studied: Do different plant oils in animal feed, with or without vitamin E, change how well quails lay eggs and how the fats in their egg yolks hold up over time?
- Who participated: 192 female Japanese quails, all about 10 weeks old at the start. They were split into six feed groups of 32 birds each, and each group was divided into four smaller pens of eight hens.
- Key finding: Quails eating canola oil or linseed oil with vitamin E laid the heaviest eggs. Across the oil diets, egg yolks had lower levels of a fat-damage marker, a sign that the yolks resisted spoiling during refrigerated storage for up to 30 days.
- What it means for you: This is early animal research, so it does not show that eating these oils or eggs will change your health. It does suggest that the type of fat in animal feed can affect egg freshness and fat quality, which may matter to egg producers and to people who care about the fats in their food.
The Research Details
Researchers ran a controlled feeding experiment over 10 weeks, covering the period when the quails were laying eggs, from about 10 to 20 weeks of age. The birds were randomly assigned to one of six diets. The diets used a 3 by 2 setup: three types of oil (sunflower, linseed, and canola, each at 3 percent of the feed) crossed with two vitamin E levels (none, or 250 milligrams per kilogram of feed).
Random assignment means that chance, not the researchers’ choices, decided which birds got which diet. This helps make sure the groups start out similar, so any differences seen later are more likely to come from the diet. Each group had 32 birds split into four pens of eight, which allowed the team to compare results across several small groups.
The team measured egg weight and egg yolk fat content at several points during the study. They also stored eggs in a refrigerator for 15 and 30 days and checked how much fat damage had built up in the yolks. This storage test shows how well the eggs keep their quality over time, which matters for real-world food handling.
The design is well organized, with clear randomization, a balanced number of birds per group, and repeated measurements. The study was published in a peer-reviewed journal. However, the sample is small, the birds were all one breed, and the study ran for only one laying period. The journal is not widely known in the nutrition field, so readers should treat these results as early evidence that needs confirmation in other studies.
What the Results Show
The main question was whether the type of oil, or adding vitamin E, changed how heavy the eggs were. The quails that received canola oil during weeks 15 to 20 and linseed oil with vitamin E for the whole trial period laid the heaviest eggs. Egg weight is an important measure for egg producers because larger eggs often sell for more.
The second major result concerned fat damage in the yolk. Researchers measured malondialdehyde, a chemical marker that rises when fats break down and go rancid. Adding plant oils to the diet lowered this marker at 15 and 20 weeks of age. The lower levels stayed lower after the eggs had been stored in the refrigerator for 15 and 30 days. In plain terms, the yolks appeared to hold up better against spoiling.
The researchers concluded that the combination of linseed oil, canola oil, and vitamin E improved egg production, fat metabolism in the yolk, and the yolk’s antioxidant protection during the laying period. They also suggested these changes might relate to heart health and a better fat profile in the egg, but this was a proposed link, not something the study directly measured in people.
Sunflower oil also contributed to the lower fat-damage levels in egg yolks, although it did not produce the same top egg weights as canola or linseed oil. The findings point to a general benefit of adding plant oils to feed rather than one single winning oil. Vitamin E seemed to add extra protection in some groups, particularly when paired with linseed oil. Because the study looked at several outcomes, some results may be the product of chance, so they should be viewed as leads for future research rather than firm conclusions.
Previous research in poultry has often found that feeding fats rich in omega-3 fatty acids, such as flaxseed (linseed) oil, can change the fatty acid makeup of eggs. Vitamin E is widely known as an antioxidant that helps slow fat breakdown. This quail study fits with that body of work by showing that these ingredients also influence egg yolk stability during storage. Still, most research in this area has been done in chickens, so the quail results add to the picture rather than settling the question.
The study used only 192 birds from a single breed, which limits how far the results can be generalized to other quails, to chickens, or to larger farms. It lasted one laying period, so it cannot show whether benefits continue over years. The study measured changes in fat-damage markers and egg weight, but it did not test how these eggs affect human health, heart disease risk, or cholesterol. The full study details may also include factors that were not summarized in the abstract, such as exact costs, feed conversion, and how the diets affected the birds’ overall health. Finally, the study was funded and reported by its authors, and it has not yet been widely repeated by independent labs.
The Bottom Line
Based on this single animal study, there is early, moderate-strength evidence that adding linseed oil, canola oil, or sunflower oil to quail feed may improve egg weight and slow fat damage in egg yolks. Adding vitamin E may add extra protection, especially with linseed oil. Confidence is low to moderate for these claims because the study is small and has not yet been repeated. Egg producers may want to test these feed changes on a small scale before making big changes.
Quail and poultry farmers, feed formulators, and researchers in animal nutrition should pay the most attention to these findings. People who buy eggs and care about fat quality may also find them interesting. Consumers should not treat this study as proof that the eggs themselves are healthier for them, and people with heart conditions or special diets should talk to a doctor or registered dietitian before making changes based on this research.
Changes in feed affect egg production within weeks, so producers might notice differences in egg weight during a single laying cycle. Changes in egg yolk fat stability were measured after storage periods of 15 and 30 days. Any health effects for people would take much longer to study and are not known from this research.
Frequently Asked Questions
Does adding flaxseed oil to animal feed make eggs healthier?
A 2026 study of 192 quails found that linseed (flaxseed) oil, especially with vitamin E, was linked to heavier eggs and lower fat-damage levels in the yolks. The study was done in animals, so it does not prove the eggs are healthier for people.
What is malondialdehyde in egg yolks?
Malondialdehyde is a chemical marker that rises when fats in food break down and go rancid. In a 2026 quail study, lower levels of this marker in egg yolks suggested that the yolks held up better against spoiling during storage.
How long do eggs stay fresh in the refrigerator according to recent quail research?
A 2026 quail study tested egg yolks after 15 and 30 days of refrigerated storage. Yolks from birds fed plant oils showed lower fat-damage markers at both time points than many untreated yolks, suggesting better stability during storage.
Can vitamin E in chicken or quail feed improve egg quality?
Vitamin E appears to add antioxidant protection in animal feed. In a 2026 study of 192 quails, adding 250 milligrams of vitamin E per kilogram of feed was tested alongside plant oils, and the combination with linseed oil produced some of the best results.
Want to Apply This Research?
- If you raise quail or other laying birds, log the average weight of eggs from each flock each week and note the type of oil and vitamin E level in the feed. Track how many eggs stay fresh after 15 and 30 days in the refrigerator by checking yolk appearance and smell at each interval.
- Use the app to compare feed batches side by side. If you are a home egg keeper, record which feed you use and how long eggs stay good, then look for patterns over several months. Share your findings with a veterinarian or poultry expert before making major feed changes.
- Track egg weight, storage life, and feed costs over at least one full laying season. Review your data every few months and compare it to baseline numbers from before any feed change. If you notice consistent improvements, consider repeating the test with a larger group of birds to confirm the results.
This article summarizes an early animal study in Japanese quails. The findings apply to feed and egg quality in birds and have not been tested for effects on human health. This information is for general education and is not medical, nutritional, or veterinary advice. Consult a qualified veterinarian, poultry specialist, or registered dietitian before making changes to feed or diet.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.