Gram Research analysis shows that feeding bromoform supplements to sheep twice daily reduces methane emissions by 60%, compared to only 38% reduction with once-daily feeding. In a study of 72 young sheep, researchers kept the total bromoform dose identical across all groups but varied the feeding schedule. Sheep receiving the supplement split between morning and afternoon meals cut methane production by 22 percentage points more than sheep receiving the full dose once daily. The timing of supplement delivery proved just as important as the total amount given.
Researchers tested different ways to give sheep a methane-reducing supplement called bromoform to see which schedule worked best. They found that giving the supplement twice a day cut methane emissions by up to 60%, compared to only 38% reduction when given once daily. The study involved 72 young sheep eating a forage diet over 61 days. Importantly, the total amount of bromoform stayed the same across all groups, so the timing of delivery made the difference. This finding suggests that how often animals receive methane-reducing additives matters just as much as the total amount they receive.
Key Statistics
A randomized controlled trial of 72 Merino sheep published in 2026 found that twice-daily bromoform supplementation reduced methane production by 60% compared to control pellets, versus only 38% reduction with once-daily bromoform feeding.
According to research reviewed by Gram, sheep receiving bromoform on alternate days with two daily feedings reduced methane by 51%, while those receiving the same total dose on alternate days with one daily feeding reduced methane by only 32%, demonstrating that within-day feeding frequency matters significantly.
The 2026 sheep study showed that splitting bromoform supplementation into two daily meals increased methane abatement by 22 percentage points (from 38% to 60%) compared to once-daily feeding, without affecting animal growth or feed conversion efficiency.
The Quick Take
- What they studied: Whether giving sheep a methane-reducing chemical called bromoform at different times of day would change how much methane they produced, even if the total amount of bromoform stayed the same.
- Who participated: Seventy-two young Merino sheep (a common wool and meat breed) weighing about 23 kilograms each, housed individually and fed a diet of lucerne and wheat chaff.
- Key finding: Sheep that received bromoform twice daily reduced their methane production by 60% compared to sheep getting control pellets twice daily. Even sheep getting bromoform once daily cut methane by 38% compared to controls receiving it once daily.
- What it means for you: If you raise sheep, the timing of when you give methane-reducing supplements matters significantly. Twice-daily feeding appears much more effective than once-daily feeding. However, this was tested in controlled conditions, so real-world grazing results may differ.
The Research Details
Scientists divided 72 young sheep into six groups and gave each group different feeding schedules over 91 days. Some groups received control pellets (no active ingredient), while others received pellets containing bromoform, a chemical that reduces methane production in the animal’s stomach. The key experiment was changing when the pellets were given: once daily in the morning, twice daily (morning and afternoon), or on alternate days. The total amount of bromoform each sheep received over two days stayed exactly the same across all bromoform groups, so researchers could isolate the effect of timing alone.
Throughout the study, scientists measured how much methane each sheep produced using special chambers that capture and measure gases. They took measurements every 19 days and also tracked how much food each sheep ate and how much weight they gained. This careful tracking allowed them to see whether the timing of supplement delivery affected methane production without changing how well the sheep grew or converted feed into body weight.
The study was designed as a randomized controlled trial, meaning sheep were randomly assigned to groups and one group received no active treatment (the control). This design helps ensure that differences between groups came from the treatment itself, not from other factors.
Understanding the best way to deliver methane-reducing supplements is important because livestock farming contributes significantly to climate change through methane emissions. If scientists can figure out the most effective feeding schedule, farmers could reduce environmental impact without needing to use more of the expensive chemical. This study is particularly valuable because it shows that timing matters as much as total dose, which is a finding that could apply to other animal treatments and supplements.
This study has several strengths: it used a large sample size (72 animals), randomly assigned animals to groups, measured methane production directly using scientific equipment rather than estimating it, and tracked multiple outcomes including growth and feed efficiency. The study lasted long enough (61 days of measurement) to see real effects. However, the study was conducted in controlled indoor conditions with individual pens, which differs from how sheep typically graze outdoors in groups. The researchers themselves noted that grazing trials in more realistic farm settings are needed to confirm these findings.
What the Results Show
The timing of bromoform delivery had a dramatic effect on methane reduction. When sheep received bromoform once daily in the morning only (DLY-1), they reduced methane production by 38% compared to sheep receiving control pellets once daily. When the same total amount of bromoform was split into two daily feedings (DLY-2), methane reduction jumped to 60% compared to sheep receiving control pellets twice daily. This 22-percentage-point difference shows that splitting the dose into two meals was significantly more effective than giving it all at once.
Alternate-day feeding also showed benefits but was less effective than daily feeding. Sheep receiving bromoform on alternate days in the morning only (ALT-1) reduced methane by 32%, while those receiving it on alternate days with two daily feedings (ALT-2) reduced methane by 51%. Comparing these results to the daily feeding groups shows that more frequent daily dosing consistently outperformed less frequent dosing.
Importantly, the total amount of bromoform each sheep received over a 48-hour period was identical across all bromoform treatment groups. This means the differences in methane reduction came purely from how the supplement was distributed across meals and days, not from receiving more or less of the active ingredient. The researchers found that the timing within a single day (morning only versus morning and afternoon) had a bigger effect on methane reduction than spreading the same dose across more days.
The study measured whether different feeding schedules affected how much the sheep grew or how efficiently they converted feed into body weight. Neither average daily weight gain nor feed conversion ratio showed significant differences between groups. This is good news because it means the methane-reducing supplement and its feeding schedule did not negatively impact the sheep’s growth or productivity. Sheep in all groups maintained normal growth rates, suggesting that optimizing the feeding schedule for methane reduction does not require sacrificing animal performance.
Previous research on bromoform in sheep showed methane reductions of only 6% to 23%, which is much lower than the 60% reduction found in this study. The key difference appears to be feeding frequency. Earlier studies typically gave bromoform once daily, while this research tested twice-daily dosing and found much better results. Interestingly, studies in cattle (both beef and dairy) have reported much higher methane reductions of 39% to 99%, and those studies also used more frequent dosing schedules. This new sheep research suggests that the species difference in previous results may have been partly due to different feeding frequencies rather than fundamental differences between sheep and cattle.
The most important limitation is that this study was conducted in controlled laboratory conditions with sheep housed individually in pens. Real sheep on farms typically graze outdoors in groups, which could affect how well they consume supplements and how their digestive systems work. The study also used young sheep (weaners) of a single breed, so results may not apply to adult sheep or other breeds. Additionally, the study only measured methane production for short periods (two days at a time) at 19-day intervals, rather than continuously. Finally, the researchers did not measure changes in the sheep’s rumen fluid chemistry that might explain why more frequent dosing worked better, so the exact biological mechanism remains unclear.
The Bottom Line
If you use bromoform or similar methane-reducing supplements for sheep, divide the daily dose into two feedings (morning and afternoon) rather than giving it all at once. This approach appears to reduce methane production by about 22 percentage points more than once-daily feeding. However, these results come from controlled research conditions, so consult with a veterinarian or animal nutritionist before changing your feeding practices. The supplement did not affect sheep growth or feed efficiency in this study, so there is no downside to trying twice-daily feeding from a productivity standpoint.
Sheep farmers and producers interested in reducing environmental impact should pay attention to these findings. Environmental scientists and policymakers working on livestock emissions will find this relevant. Feed manufacturers and supplement companies could use this information to recommend better dosing schedules. However, if you raise cattle or other livestock species, these results may not directly apply, though they suggest that feeding frequency deserves investigation in those species too.
Methane reduction appeared immediately when sheep switched to twice-daily feeding. The study measured methane production at 19-day intervals and found consistent effects throughout the 61-day measurement period, suggesting that the benefit is sustained over time. You would not need to wait weeks to see whether a twice-daily feeding schedule is working, as the effect should be apparent within the first few measurement cycles.
Frequently Asked Questions
How much does twice-daily bromoform feeding reduce methane in sheep compared to once-daily feeding?
Twice-daily bromoform feeding reduced methane by 60% versus 38% for once-daily feeding, a difference of 22 percentage points. This improvement occurred without changing the total bromoform dose, showing that timing of delivery significantly affects effectiveness.
Does giving bromoform supplements more frequently affect how much sheep grow?
No, the study found no significant differences in weight gain or feed conversion between sheep receiving bromoform on different schedules. All groups maintained normal growth rates, indicating that optimizing supplement timing does not compromise animal productivity.
Why does bromoform work better when given twice daily instead of once daily?
The exact biological mechanism is unclear from this study, but researchers suggest that more frequent dosing may maintain higher levels of the active ingredient in the sheep’s digestive system. The rumen (stomach) may process the supplement more effectively when it arrives in smaller, more frequent doses.
Can these sheep results be applied to cattle or other livestock?
These findings are specific to sheep in controlled conditions. Previous cattle studies used more frequent dosing and achieved higher methane reductions (39-99%), suggesting frequency matters in cattle too, but direct comparison requires additional research in cattle.
Would these results apply to sheep grazing outdoors on pasture?
This study used sheep in individual pens indoors, so results may differ in grazing conditions. The researchers specifically noted that grazing trials in near-commercial environments are needed to confirm whether twice-daily feeding remains superior in real-world farm settings.
Want to Apply This Research?
- Track daily methane production (in grams per day) for each animal or group, recorded at consistent times. Compare methane levels before and after switching to twice-daily bromoform supplementation, noting the date of the change. Record the exact times of morning and afternoon feedings to ensure consistency.
- If using a livestock management app, set up feeding reminders for both morning and afternoon bromoform supplement delivery. Create a custom alert system that tracks whether supplements were delivered on schedule, since timing appears critical to effectiveness. Log any changes in animal behavior or feed intake that might indicate the supplement is working.
- Establish a baseline methane measurement before starting twice-daily supplementation, then measure every 19 to 21 days using the same method and time of day. Create a simple chart showing methane levels over time to visualize whether the twice-daily schedule is delivering the expected 60% reduction. Compare actual results to the 38% reduction you would expect from once-daily feeding to verify the benefit of your new schedule.
This research was conducted on young sheep in controlled laboratory conditions and may not apply directly to adult sheep, different breeds, grazing systems, or other livestock species. Bromoform is a chemical compound that may be regulated differently in various countries and jurisdictions. Before implementing any changes to your sheep feeding program, consult with a veterinarian, animal nutritionist, or your local agricultural extension office. This article summarizes research findings and should not be considered veterinary or agricultural advice. Individual animal responses may vary, and farm-specific factors such as diet composition, climate, and management practices can influence results.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.