According to Gram Research analysis, replacing soybean oil with linseed oil in dairy sheep feed does not meaningfully improve their recovery from udder infections. A 2026 study of 22 lactating sheep found that both groups recovered similarly from a bacterial udder challenge within three weeks, with only minor differences in feed intake and blood enzymes between diets. The omega-3 rich linseed oil provided no significant advantage over the omega-6 rich soybean oil for fighting inflammation or speeding recovery.
Researchers tested whether switching dairy sheep from soybean oil to linseed oil could help them recover faster from udder infections. Linseed oil is rich in omega-3 fatty acids, which are known to reduce inflammation in the body. The study involved 22 lactating sheep that were given either soybean oil or linseed oil in their feed, then exposed to a mild bacterial infection in their udders. While both groups recovered well, the linseed oil diet didn’t provide any extra benefit compared to soybean oil. The findings suggest that simply changing the type of oil in sheep feed may not be enough to improve their immune response to udder infections.
Key Statistics
A 2026 research article published in the Journal of Dairy Science tested 22 lactating Assaf sheep and found that replacing soybean oil with linseed oil produced almost no meaningful differences in immune response or recovery time from an induced udder infection.
In the study, both sheep groups recovered from the bacterial udder challenge within three weeks, with milk production and immune markers returning to normal levels regardless of whether they were fed soybean oil or linseed oil.
The only statistically significant differences between the linseed oil and soybean oil groups were minor variations in daily feed intake and a blood enzyme called lactate dehydrogenase, changes too small to matter in practical sheep farming.
The Quick Take
- What they studied: Whether feeding dairy sheep linseed oil (rich in omega-3s) instead of soybean oil (rich in omega-6s) would help them recover faster from udder infections.
- Who participated: 22 lactating Assaf sheep (a dairy breed) were divided into two groups: one fed soybean oil and one fed linseed oil for several weeks.
- Key finding: Both groups recovered similarly from the induced udder infection, with no meaningful advantage for the linseed oil group. Most health markers returned to normal within 3 weeks in both groups.
- What it means for you: If you raise dairy sheep, switching to linseed oil alone won’t significantly improve their ability to fight udder infections. Other strategies may be needed to support sheep health during infections.
The Research Details
This was a controlled experiment where researchers deliberately gave dairy sheep a mild udder infection to see how different diets affected their recovery. The 22 sheep were split into two equal groups: one group received feed supplemented with 2% soybean oil (which contains omega-6 fatty acids that promote inflammation), while the other group received the same feed but with linseed oil instead (which contains omega-3 fatty acids that reduce inflammation). Before the infection was introduced, the sheep ate their assigned diet for several weeks to allow their bodies to adjust. Then researchers injected a harmless bacterial component into each sheep’s udder to trigger a mild, controlled infection. The researchers measured multiple health indicators before the infection, immediately after, and for three weeks afterward, including how much the sheep ate, how much milk they produced, milk quality, and various blood markers of immune function.
This research approach is important because it creates a controlled situation where scientists can isolate the effect of diet on immune response. By deliberately causing a mild infection rather than waiting for natural disease, researchers can ensure all sheep experience the same challenge at the same time, making it easier to compare the two diets fairly. The three-week monitoring period allows researchers to track not just the immediate response but also how quickly each group recovers.
This study has several strengths: it used a controlled experimental design with clear before-and-after measurements, it monitored multiple health indicators rather than just one, and it tracked recovery over time. However, the study involved only 22 sheep, which is a relatively small number, so results may not apply to all sheep populations. The infection was intentionally mild, so results might differ with more severe infections. The study was published in the Journal of Dairy Science, a respected peer-reviewed journal in animal nutrition.
What the Results Show
The main finding was that switching from soybean oil to linseed oil produced almost no meaningful differences in how the sheep responded to or recovered from the udder infection. Both groups showed similar patterns: their feed intake dropped after the infection, their milk production decreased temporarily, and their immune cell counts in the blood decreased. Importantly, both groups recovered well, with most measurements returning to normal levels within three weeks. The only statistically significant differences between groups were very minor—one group had slightly different feed intake on certain days, and there were small differences in a blood enzyme called lactate dehydrogenase. These differences were so small that they wouldn’t matter in real-world sheep farming.
The study confirmed that the bacterial challenge itself caused predictable changes in the sheep’s bodies: milk production dropped by about 30-40% immediately after infection, the number of white blood cells in the udder increased dramatically (a normal immune response), and overall feed intake decreased. Interestingly, the sheep’s bodies handled this mild infection very efficiently—most returned to normal function within a few days to a week. Milk composition (fat and protein content) remained relatively stable despite the infection, suggesting the sheep’s bodies prioritized maintaining milk quality even while fighting infection.
Previous research has shown that omega-3 fatty acids generally reduce inflammation in the body, which is why scientists hypothesized they would help sheep recover from infections. However, this study suggests that simply adding omega-3 oils to feed may not be enough to meaningfully improve immune response to udder infections in sheep. This doesn’t mean omega-3s are useless—it may mean that other factors (like overall nutrition, genetics, or infection severity) play larger roles, or that the benefit of omega-3s only appears in more severe infections.
The study had several limitations worth noting: only 22 sheep were tested, which is a small number that may not represent all sheep populations; the infection was intentionally mild, so results might differ with naturally occurring, more severe infections; the study only lasted three weeks after infection, so long-term effects weren’t measured; and the study focused only on sheep, so results may not apply to other dairy animals like cows. Additionally, the researchers only tested one specific amount of oil (2% of the diet), so different amounts might produce different results.
The Bottom Line
Based on this research, farmers should not expect that simply switching from soybean oil to linseed oil will significantly improve their sheep’s ability to fight udder infections. If udder infections are a problem in your flock, other strategies—such as improved milking hygiene, better housing conditions, or veterinary treatment—are likely to be more effective. However, omega-3 fatty acids may still have other health benefits not measured in this study, so the decision to use linseed oil should be based on overall farm management goals rather than infection prevention alone. Confidence level: Moderate—the study was well-designed but involved a small number of animals.
Dairy sheep farmers should pay attention to these findings, especially those considering dietary changes to prevent mastitis (udder infections). Veterinarians advising sheep farmers should know that oil type alone is unlikely to be a game-changer for infection prevention. This research is less relevant to people raising other types of livestock or to consumers, as it specifically addresses sheep nutrition.
In this study, sheep recovered from the mild infection within 3 weeks regardless of diet. If you were to change your sheep’s diet, you wouldn’t expect to see dramatic improvements in infection prevention immediately—any benefits would likely take weeks or months to appear, if they appear at all.
Frequently Asked Questions
Does omega-3 oil help sheep fight udder infections?
A 2026 study of 22 sheep found that linseed oil (rich in omega-3s) provided no meaningful advantage over soybean oil (rich in omega-6s) in fighting udder infections. Both groups recovered similarly within three weeks, suggesting diet alone may not be the key factor in infection recovery.
Should I switch my dairy sheep to linseed oil to prevent mastitis?
Based on this research, switching to linseed oil alone is unlikely to significantly prevent mastitis in sheep. Other strategies like improved milking hygiene, better housing, and prompt veterinary treatment are likely more effective for preventing udder infections.
How long does it take sheep to recover from udder infections?
In this study, sheep recovered from a mild bacterial udder infection within three weeks, with most health markers returning to normal within days to a week. Recovery time may vary depending on infection severity and overall flock health management.
What’s the difference between omega-3 and omega-6 fatty acids for animal health?
Omega-3 fatty acids generally reduce inflammation, while omega-6 fatty acids tend to promote it. However, this study shows that simply switching between them in sheep feed doesn’t significantly improve immune response to udder infections, suggesting other factors are more important.
Can diet changes improve sheep immune function?
While diet plays a role in overall health, this study suggests that changing oil type alone won’t dramatically improve a sheep’s ability to fight infections. A comprehensive approach including nutrition, hygiene, housing, and veterinary care is likely more effective than any single dietary change.
Want to Apply This Research?
- If managing a dairy sheep operation, track weekly milk production and somatic cell count (SCC) in milk samples. Record any mastitis cases with date, severity, and treatment. Compare these metrics month-to-month to identify trends, rather than expecting immediate changes from dietary modifications.
- If you’re a sheep farmer considering this diet change, focus instead on tracking and improving milking hygiene practices, udder health monitoring, and prompt treatment of infections. Use the app to log daily observations of individual sheep’s udder health and milk appearance rather than relying on diet alone.
- Establish a baseline of your current infection rates and milk quality over 2-3 months. If you do make dietary changes, continue monitoring these same metrics for at least 3-6 months to determine if any real improvements occur. Document any changes in feed intake, milk yield, or health events to build a complete picture of your flock’s response.
This research applies specifically to dairy sheep and may not generalize to other livestock species. The study involved a mild, controlled infection rather than naturally occurring disease, so results may differ in real-world conditions. This information is for educational purposes and should not replace professional veterinary advice. Farmers considering dietary changes to prevent mastitis should consult with a veterinarian or animal nutritionist to develop a comprehensive herd health strategy. Individual sheep may respond differently to dietary interventions based on genetics, overall health status, and management practices.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.