According to Gram Research analysis, both nitrate and 3-NOP feed additives significantly reduce methane emissions from dairy cows, with 3-NOP reducing methane by 29% and nitrate by 19% in a study of 201 first-lactation Holstein cows. However, the additives work best in different types of cows: 3-NOP is most effective in high-producing cows with good feed intake, while nitrate works better in cows that naturally produce high amounts of methane. This means farmers may get better results by matching the additive to each cow’s individual characteristics rather than using the same additive for all cows.
Researchers tested two feed additives designed to reduce methane gas from dairy cows and discovered that the additives work differently depending on each cow’s individual characteristics. In a study of 201 first-lactation Holstein cows, methane emissions dropped by 19% to 29% when cows ate special feeds containing nitrate or 3-NOP. However, cows with higher milk production and better feed intake responded best to these additives. The findings suggest that farmers might get better results by matching feed additives to each cow’s natural traits, rather than using a one-size-fits-all approach.
Key Statistics
A 2026 study of 201 first-lactation Holstein dairy cows found that the 3-NOP feed additive reduced methane emissions by 29% and nitrate reduced them by 19% compared to a control diet.
Research published in the Journal of Dairy Science in 2026 showed that high-producing dairy cows responded best to the 3-NOP additive, while cows with naturally high methane production responded better to nitrate supplementation.
In a controlled study of 201 dairy cows, the 3-NOP additive reduced methane intensity (methane per unit of milk) by 28%, though it also decreased feed intake by 4% and milk production compared to the control diet.
A 2026 analysis of 201 Holstein cows revealed that cows with higher ruminal propionic acid proportions showed poorer methane reduction responses to nitrate, demonstrating that stomach chemistry influences additive effectiveness.
The Quick Take
- What they studied: Whether two different feed additives (nitrate and 3-NOP) could reduce the amount of methane gas that dairy cows produce, and whether some cows respond better to these additives than others.
- Who participated: 201 young Holstein dairy cows in their first lactation cycle. The cows were divided into three groups and fed different diets over a 21-day period to compare how much methane each group produced.
- Key finding: Both additives significantly reduced methane emissions: nitrate reduced methane by 19% and 3-NOP reduced it by 29%. However, cows that produced more milk and ate more feed showed the biggest reductions in methane when given 3-NOP, while cows that naturally produced high amounts of methane responded better to nitrate.
- What it means for you: If you work in dairy farming, this research suggests that using these feed additives could help reduce environmental impact from cattle. However, the additives work best in certain types of cows, so farmers may need to test which additive works best for their specific herd. For consumers, this could eventually lead to more environmentally friendly milk production.
The Research Details
Scientists conducted a controlled experiment using 201 first-lactation Holstein cows, which are young cows having their first calf. The cows were divided into three groups, each receiving a different diet for 21 days at a time. One group ate a regular control diet, one group ate feed mixed with nitrate (a chemical compound), and one group ate feed containing 3-NOP (another chemical compound designed to reduce methane). The researchers measured how much methane each cow produced, how much feed they ate, how much milk they made, and their body weight. They also collected samples of stomach fluid, milk, and blood to understand what was happening inside each cow’s digestive system.
The study used a Latin square design, which is a special arrangement that helps researchers compare treatments fairly by having each cow experience each diet at different times. This design reduces the effect of individual cow differences and makes it easier to see the true effect of each diet. The researchers used statistical models to analyze the data, looking at how each cow deviated from average responses to understand why some cows benefited more from the additives than others.
The key innovation was examining individual cow characteristics, such as milk production level, feed intake, and the types of acids produced in their stomachs, to predict which cows would respond best to each additive. This personalized approach to understanding methane reduction is more useful for farmers than just knowing the average effect across all cows.
Understanding why some cows respond better to methane-reducing additives than others is important because it allows farmers to use these additives more efficiently. Rather than giving the same additive to all cows, farmers could potentially match additives to individual cows based on their characteristics, saving money and improving environmental outcomes. This research also helps scientists understand the biological mechanisms behind methane production in cattle, which could lead to better additives in the future.
This study has several strengths that make the findings reliable. The sample size of 201 cows is substantial, providing good statistical power to detect real differences. The controlled Latin square design is a gold standard in animal nutrition research because it accounts for individual animal variation. The researchers measured multiple outcomes (methane, milk production, feed intake, body weight, and stomach chemistry) rather than just one, giving a complete picture of how the additives work. The study was published in the Journal of Dairy Science, a peer-reviewed journal with high standards. However, the study only looked at first-lactation Holstein cows, so results may not apply to older cows or other dairy breeds. The study was also conducted in a controlled research setting, which may differ from typical farm conditions.
What the Results Show
Both feed additives successfully reduced methane emissions from dairy cows. The nitrate additive reduced methane yield (the amount of methane produced per unit of feed eaten) by 19%, while the 3-NOP additive reduced it by 28 to 29%. When measuring methane intensity (methane per unit of milk produced), nitrate reduced it by 20% and 3-NOP reduced it by 28%. These reductions are substantial and suggest both additives have real potential for reducing the environmental impact of dairy farming.
However, the additives had different effects on other important measures. When cows ate the nitrate diet, they maintained their normal feed intake and milk production stayed stable. In contrast, when cows ate the 3-NOP diet, they ate 4% less feed and produced less milk, while also losing more body weight. This suggests that 3-NOP may have a cost in terms of reduced productivity, even though it reduces methane more effectively.
The most important finding was that individual cow characteristics strongly influenced how well each additive worked. Cows that naturally produced high amounts of methane responded best to the nitrate additive, while cows with higher milk production and better feed intake responded best to 3-NOP. This suggests that the same additive does not work equally well for all cows, and farmers might achieve better results by matching additives to individual cow characteristics.
The researchers discovered that cows with naturally high methane production had different stomach chemistry than low-methane cows. High-methane cows had higher levels of acetic and butyric acids in their stomachs, while low-methane cows had higher levels of propionic acid. These differences in stomach acid composition appear to influence how well each additive works. Additionally, cows with high ruminal ammonia (a nitrogen compound in the stomach) responded differently to the additives, with nitrate being more effective in cows with low ammonia levels. The additives also affected milk composition differently depending on cow characteristics, with 3-NOP producing higher milk energy content in cows with high milk fat or lactose, but lower energy content in cows with naturally high methane production.
This research builds on previous studies showing that both nitrate and 3-NOP can reduce methane in dairy cows, but it goes further by explaining why individual cows respond differently. Earlier research established that these additives work by changing how food is broken down in the cow’s stomach, but this study identifies specific cow characteristics that predict which additive will work best. The finding that high-producing cows respond better to 3-NOP aligns with some previous research suggesting that additives may work better in more efficient cows. However, the finding that high-methane cows respond better to nitrate is a new insight that could help farmers make better decisions about which additive to use.
This study only examined first-lactation (young) Holstein cows, so the results may not apply to older cows or other dairy breeds that might respond differently to these additives. The study was conducted in a controlled research setting with carefully managed diets and conditions, which may differ from typical farm environments where cows eat more variable feed and experience different stresses. The study lasted only 21 days per treatment period, so it does not show whether the additives remain effective over longer periods or whether cows adapt to them over time. Additionally, the study did not examine the cost-effectiveness of using these additives on real farms, so farmers would need to do their own economic analysis. Finally, the study measured methane production using indirect methods rather than directly capturing all methane, which could introduce some measurement error.
The Bottom Line
Based on this research, dairy farmers should consider using methane-reducing feed additives, particularly 3-NOP for high-producing cows and nitrate for cows with naturally high methane production. However, farmers should be aware that 3-NOP may reduce feed intake and milk production in some cows, so careful monitoring is needed. Before implementing these additives on a large scale, farmers should test them on a small group of cows to see how their specific herd responds. The confidence level for these recommendations is moderate to high for methane reduction, but lower for predicting effects on milk production and feed intake in individual herds.
Dairy farmers and agricultural professionals should care about this research because it offers practical tools for reducing environmental impact while maintaining productivity. Environmental regulators and sustainability-focused consumers should care because methane reduction from cattle is important for climate change mitigation. Veterinarians and animal nutritionists should care because this research helps them make better recommendations to farmers. However, small-scale farmers with limited resources may find the cost of these additives prohibitive, and farmers in regions with different cattle breeds or management systems may need to conduct their own trials before adopting these additives.
Farmers should expect to see methane reductions within the first few weeks of feeding these additives, as the study showed effects within 21 days. However, effects on milk production and body weight may take longer to stabilize, so farmers should monitor cows for at least 4 to 8 weeks before making final decisions about continuing the additives. The long-term sustainability of these effects beyond several months is not yet known from this research.
Frequently Asked Questions
Do methane-reducing feed additives work for all dairy cows?
No, effectiveness varies by individual cow. A 2026 study of 201 cows found that 3-NOP works best in high-producing cows, while nitrate is more effective in cows with naturally high methane production. Farmers should test additives on their specific herd to see which works best.
How much methane can feed additives reduce in dairy cows?
Research shows 3-NOP reduces methane by 28 to 29%, while nitrate reduces it by 19 to 20%. These reductions are measured both as total methane produced and as methane per unit of milk produced, making both additives potentially valuable for reducing environmental impact.
Will methane-reducing additives affect my cow’s milk production?
It depends on the additive. Nitrate maintains normal milk production, but 3-NOP may reduce milk production by a small amount while also reducing feed intake by about 4%. Farmers should monitor individual cows to see how they respond.
What determines whether a cow will respond well to methane additives?
Cow characteristics like milk production level, feed intake, body weight, and stomach chemistry influence response. A 2026 study found that cows with high milk production respond best to 3-NOP, while cows with naturally high methane production respond better to nitrate supplementation.
How quickly do methane-reducing additives start working?
Research shows effects appear within 21 days of feeding the additive. However, farmers should monitor cows for 4 to 8 weeks to see the full impact on milk production and body weight before deciding whether to continue using the additive.
Want to Apply This Research?
- Track daily feed intake (in kilograms), milk production (in liters), and body weight (in kilograms) for each cow before and after introducing the methane-reducing additive. Record these measurements at the same time each day to ensure consistency. Compare the data from the two weeks before starting the additive to the data from weeks 3 to 4 after starting it to see if the additive is working as expected for your specific cows.
- If using a dairy management app, input which cows are receiving which additive and set reminders to monitor their feed intake and milk production daily. Create alerts if any cow’s feed intake drops more than 5% or milk production drops more than 10%, as these could indicate the additive is not working well for that individual cow. Use the app to compare responses across your herd to identify which cows benefit most from each additive.
- Establish a baseline measurement period of 2 to 3 weeks before introducing the additive, recording feed intake, milk production, and body weight for each cow. After starting the additive, continue measuring these same variables weekly for at least 8 weeks. Use the app to calculate the percentage change from baseline for each cow. Cows showing greater than 20% reduction in methane-related metrics (based on feed intake and milk production patterns) are responding well, while cows showing less than 10% reduction may benefit from switching to a different additive or discontinuing use.
This research describes the effects of feed additives (nitrate and 3-NOP) on methane production in dairy cows under controlled research conditions. Results may vary in real-world farm settings depending on cow breed, age, diet composition, and management practices. Before implementing these additives on your farm, consult with a veterinarian or animal nutritionist to ensure they are appropriate for your specific herd and to monitor for any adverse effects. This article is for informational purposes only and should not replace professional agricultural or veterinary advice. The study only examined first-lactation Holstein cows, so results may not apply to other breeds or older cows. Long-term safety and efficacy data beyond the study period are not available.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.