Researchers tested a special feed additive called 3-NOP that helps reduce the amount of methane gas that dairy cows produce. Methane is a greenhouse gas that contributes to climate change. In a year-long study with 79 Norwegian dairy cows, scientists discovered that cows don’t all respond the same way to this additive—some cows reduced their methane emissions more than others. This difference appears to be partly genetic, meaning it’s passed down through families of cows. The findings suggest that farmers might be able to breed cows that naturally respond better to methane-reducing feed additives in the future.
The Quick Take
- What they studied: Whether dairy cows have different genetic abilities to reduce their methane gas emissions when given a special feed additive
- Who participated: 79 Norwegian Red dairy cows on a working farm. Some cows (54) received the feed additive for a year, while 25 cows served as a comparison group without the additive
- Key finding: Cows showed different levels of response to the feed additive, and about 15% of this difference appears to be due to genetics. This means some cows are naturally better at reducing methane when given this additive
- What it means for you: If you work with dairy farms or care about reducing greenhouse gases, this suggests farmers could eventually breed cows that are naturally better at reducing methane. However, this is early research with a small group of cows, so more studies are needed before making big changes
The Research Details
Scientists conducted a one-year study on a real dairy farm in Norway. They measured how much methane gas each cow produced using special equipment called a GreenFeed unit. They collected over 14,000 daily measurements of methane from the cows. Some cows received a feed additive (3-NOP) at a dose of 1.2 to 1.5 grams per day, while other cows ate regular feed without the additive. The researchers measured each cow’s methane levels during periods without the additive (to establish a baseline) and then compared it to their methane levels after receiving the additive. This allowed them to calculate how much each individual cow reduced their methane in response to the additive. They then used statistical methods to determine if the differences in how cows responded were related to their genetics.
This research approach is important because it looks at real cows on a real farm rather than just laboratory conditions. By measuring the same cows over time and comparing their baseline methane to their methane after receiving the additive, researchers could see individual differences in response. Using genetic analysis on these individual responses helps identify whether these differences are inherited traits that could be selected for in breeding programs
This study has some important limitations to understand. The sample size is relatively small (79 cows total, with only 42 cows receiving the additive), which means the results are less certain than studies with larger groups. The researchers themselves note that results should be interpreted cautiously. However, the study was conducted on a working farm with real cows, which makes the findings more applicable to actual farming conditions. The long measurement period (one year) and large number of daily measurements (over 14,000) provide good quality data for each cow
What the Results Show
The study found that cows produced an average of 387 grams of methane per day. When cows received the 3-NOP feed additive, they reduced their methane emissions, but the amount of reduction varied significantly from cow to cow. Some cows responded very well to the additive and reduced their methane a lot, while others showed smaller reductions. The researchers calculated that about 15% of the variation in how well cows responded to the additive was due to genetic differences between cows. This is a moderate level of genetic influence, suggesting that breeding could potentially improve how well cows respond to this type of feed additive. The standard error of 0.03 indicates there is some uncertainty in this estimate, but the finding still suggests real genetic variation exists
The study also tracked how methane production changed based on other factors like how many times a cow had given birth (parity), what stage of lactation the cow was in, and the specific test day. These factors all influenced methane production, but the main finding about genetic variation in response to the additive remained consistent even after accounting for these other factors
Previous research has shown that 3-NOP feed additives can reduce methane emissions in dairy cows by about 30% on average. This study builds on that knowledge by asking a new question: do all cows benefit equally? The finding that genetic variation exists in response to the additive is novel and suggests that future research could identify which cows or cow breeds are naturally better responders. This aligns with the broader agricultural trend of using genetics to improve farming practices
The main limitation is the small number of cows studied (only 42 cows received the additive), which makes the results less certain than larger studies would be. The study lasted one year, which is good, but longer-term studies might show different patterns. The study only included one breed (Norwegian Red cows) in one country, so results might not apply to other cow breeds or different farming conditions. The researchers only tested one specific feed additive at one specific dose, so we don’t know if other additives or different amounts would show similar genetic variation. Finally, the study was conducted on one commercial farm, so results from different farms or farming systems might differ
The Bottom Line
Based on this research, farmers interested in reducing methane emissions may want to consider using 3-NOP feed additives, as they appear effective. However, this study suggests that in the future, farmers might be able to select breeding animals that naturally respond better to these additives. At this point, the recommendation is moderate confidence—the additive works, but we need more research to understand individual cow differences. Farmers should consult with their veterinarians or agricultural advisors before making changes to their feeding programs
Dairy farmers and agricultural professionals should pay attention to this research, especially those interested in reducing their environmental impact. Environmental scientists and policymakers working on climate change solutions may find this relevant. Cattle breeders could use this information to guide future breeding decisions. General consumers who care about sustainable dairy farming might find this interesting. However, individual consumers don’t need to change their behavior based on this single study—it’s primarily relevant to people working in agriculture
If a farmer started using 3-NOP feed additives today, they would likely see methane reductions within weeks, as previous research shows the additive works relatively quickly. However, if farmers wanted to breed cows that naturally respond better to the additive, that would take many years (typically 5-10 years for noticeable changes through selective breeding). More research is needed before we can predict how long it would take to develop a population of cows with significantly improved responses
Want to Apply This Research?
- If using a dairy farm management app, track daily methane emissions (if you have measurement equipment) or track feed additive usage and correlate it with milk production and cow health metrics. Record which individual cows show the best response to the additive by monitoring changes in their productivity and health indicators
- Farmers could implement a trial period where they add 3-NOP to their herd’s feed and track methane reduction (if measurable) or monitor for any changes in milk production, feed efficiency, or cow health. They could also begin keeping detailed records on individual cow responses to identify which animals might be naturally better responders for future breeding decisions
- Establish a baseline measurement of methane or related metrics before introducing the additive, then monitor monthly for at least 3-6 months to see individual cow responses. Keep records organized by individual cow to identify patterns. If possible, work with a veterinarian or agricultural extension service to ensure proper tracking and interpretation of results over time
This research is preliminary and based on a small study of 79 cows. Results should not be considered definitive guidance for farm management decisions. Before implementing any changes to cattle feed or management practices, consult with a veterinarian, animal nutritionist, or agricultural extension specialist. This study examines genetic potential in one breed under specific conditions and may not apply to all farms, regions, or cattle breeds. The findings are intended for agricultural professionals and researchers, not as medical or veterinary advice. Always follow local regulations and best practices for animal care when implementing new feeding strategies.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.