Scientists tested whether adding freeze-dried beneficial bacteria called Lactobacillus to lambs’ food could help them grow better and produce less methane gas (a type of pollution). Over 70 days, lambs that received this bacteria supplement grew 24% faster than lambs without it. The treated lambs also produced 30% less methane relative to their growth. This research suggests that using natural, safe bacteria supplements could help farms raise healthier animals while reducing environmental pollution from livestock.

The Quick Take

  • What they studied: Whether adding freeze-dried beneficial bacteria (Lactobacillus) to lamb feed would help them grow faster and produce less methane gas
  • Who participated: Growing lambs fed hay-based diets over a 70-day period; specific number of lambs not provided in the abstract
  • Key finding: Lambs receiving the bacteria supplement grew 24% faster and produced 30% less methane relative to their growth compared to lambs without the supplement
  • What it means for you: If you raise sheep or care about sustainable farming, this suggests a simple, natural way to improve animal growth and reduce environmental impact. However, these results are from a controlled study and may work differently on actual farms with varying conditions

The Research Details

Researchers divided growing lambs into two groups: one received freeze-dried Lactobacillus bacteria mixed into their grain feed (providing a very high dose of beneficial bacteria), while the other group received regular feed without the bacteria. Both groups ate hay-based diets for 70 days. Scientists measured how much weight the lambs gained, tracked changes in their body condition, collected and measured the methane gas they produced, and examined their carcass characteristics at the end.

The bacteria used were freeze-dried, meaning they were dried out to preserve them and make them easier to mix into feed. This freeze-drying process is important because it helps the bacteria survive better when stored and delivered to the animals. The researchers carefully controlled the feeding to ensure each lamb received the same amount of bacteria supplement.

This study design is important because it tests whether beneficial bacteria can work in a practical feeding situation (hay-based diets) rather than just in laboratory conditions. The 70-day timeframe is long enough to see real changes in growth and methane production. By measuring both growth and methane emissions, the researchers could determine whether the bacteria helped the lambs use their food more efficiently, which is the key to reducing pollution while improving productivity.

This is a controlled experiment published in a peer-reviewed scientific journal, which means other experts reviewed the work before publication. The study measured multiple outcomes (growth, body condition, methane production, and carcass quality), which strengthens the findings. However, the specific number of lambs used in the study was not provided in the abstract, which makes it harder to assess the study’s statistical power. The results show statistical significance for the main findings (growth and methane intensity), though methane production overall showed only a trend toward improvement rather than clear statistical significance.

What the Results Show

The most important finding was that lambs receiving the freeze-dried Lactobacillus bacteria grew significantly faster than control lambs. Specifically, their average daily weight gain was 24% greater, which is a substantial improvement. This means that over the 70-day study period, the treated lambs gained noticeably more weight each day compared to untreated lambs.

The second major finding involved methane production. Methane intensity—which measures how much methane is produced relative to how much weight the lamb gains—was 30% lower in the bacteria-treated group. This is important because it suggests the lambs were using their food more efficiently. While the total amount of methane produced each day showed only a slight (non-significant) decrease, the fact that methane intensity dropped significantly means the bacteria helped the lambs convert feed into body weight more efficiently, producing less pollution per pound of growth.

Body condition score, which measures how healthy and well-fed the lambs looked, also improved more in the treated group—28% greater change over the study period. This suggests the bacteria supplement helped the lambs develop better overall health and muscle development, not just gain weight.

The carcass characteristics (meat quality measurements) showed a tendency toward improvement in the bacteria-treated group, with slightly heavier carcasses, though this difference was not statistically significant. This suggests the bacteria may have helped produce slightly better-quality meat, though more research would be needed to confirm this. The results indicate that the bacteria supplement affected how the lambs’ bodies developed, not just how much they weighed.

Previous research had shown that Lactobacillus bacteria could reduce methane in ruminant animals (like sheep and cattle), but scientists weren’t sure how well this would work in practical farming situations, especially with animals grazing or eating hay. This study confirms that the bacteria can work effectively in a more realistic feeding scenario. The magnitude of improvement in growth (24%) is notably strong compared to many other feed additives tested in similar studies, suggesting this particular bacteria formulation may be particularly effective.

The study abstract does not specify how many lambs were used, which makes it difficult to assess whether the sample size was large enough to detect real differences. The study was conducted under controlled conditions with hay-based diets, so results may differ on actual farms where lambs eat different types of feed or graze on pasture. The study lasted 70 days, which is a reasonable timeframe but doesn’t tell us whether the benefits would continue if lambs received the supplement for longer periods. Additionally, the study measured methane production in a controlled setting, which may not perfectly reflect methane production in real farm environments. The study did not provide information about cost-effectiveness, which would be important for farmers deciding whether to use this supplement.

The Bottom Line

Based on this research, freeze-dried Lactobacillus supplementation appears to be a promising tool for improving lamb growth and reducing methane emissions. The evidence is moderately strong for growth improvement and methane intensity reduction. However, farmers should consider: (1) This was a controlled study, so real-world results may vary; (2) The cost of the supplement compared to the value of improved growth; (3) Whether their specific farming situation matches the study conditions (hay-based diet, growing lambs); (4) Consulting with a veterinarian or animal nutritionist before implementing this on their farm. Confidence level: Moderate for growth benefits, Moderate for methane reduction.

Sheep farmers, especially those raising lambs for meat production, should be interested in these findings. Environmental advocates concerned about livestock’s impact on climate change may also find this relevant. This research is less directly applicable to people who don’t raise livestock, though it does relate to broader questions about sustainable food production. The findings are specific to growing lambs and may not apply to adult sheep or other animals.

Based on the study, improvements in growth rate and methane intensity appeared within the 70-day study period. Farmers could likely expect to see changes in lamb growth within a few weeks of starting supplementation, though the full benefits may take several weeks to become apparent. The study doesn’t indicate whether benefits would continue indefinitely or plateau over time.

Want to Apply This Research?

  • If managing a flock, track daily weight gain (in pounds or kilograms) and feed efficiency (pounds of feed per pound of weight gained) weekly for lambs receiving the supplement versus control lambs. This allows direct comparison to the study’s 24% improvement metric.
  • For farmers: Implement a controlled feeding protocol where freeze-dried Lactobacillus supplement is mixed into grain at the recommended dose (1 × 10¹¹ CFU per kilogram of feed) and provided daily to growing lambs. For general users interested in sustainable food: Support or purchase from farms using science-backed methods like this to reduce livestock’s environmental impact.
  • Track lamb weight weekly and calculate average daily gain monthly. Monitor feed consumption to calculate feed efficiency. If possible, measure methane production using available farm tools or work with researchers. Compare results to baseline performance before supplementation began. Continue monitoring for at least 70 days to match the study duration and allow time for benefits to fully manifest.

This research describes results from a controlled scientific study on sheep and should not be considered medical or veterinary advice. Before implementing any feed supplements or changes to livestock management, consult with a licensed veterinarian or animal nutritionist familiar with your specific farming situation. Results from controlled studies may not replicate in all farm environments due to differences in feed, climate, animal genetics, and management practices. This summary is for informational purposes and does not constitute professional agricultural or veterinary guidance. Always follow label instructions and local regulations when using any animal feed additives.