According to Gram Research analysis, adding Tithonia diversifolia silage to lambs’ feed reduces heat stress in tropical climates. A 2026 study of 20 lambs found that those eating a 50-50 mixture of sugarcane and Tithonia diversifolia silage had significantly lower body temperatures and slower respiratory rates compared to lambs eating only sugarcane, with no increase in methane production.
Researchers tested whether adding a tropical plant called Tithonia diversifolia to lambs’ feed could help them handle heat better. Twenty young lambs were split into two groups: one eating only sugarcane silage and another eating a mix of sugarcane and Tithonia. The lambs eating the plant mixture had lower body temperatures and slower breathing rates, suggesting they were more comfortable in hot conditions. Interestingly, both groups produced similar amounts of methane gas, which is important for understanding how livestock affects the environment. This research suggests that mixing in Tithonia diversifolia could help farmers raise healthier lambs in tropical climates.
Key Statistics
A 2026 research study of 20 crossbred lambs found that lambs fed a 50-50 mixture of sugarcane silage and Tithonia diversifolia silage showed significantly lower body temperatures and respiratory rates compared to lambs fed sugarcane silage alone, suggesting improved heat tolerance in tropical conditions.
According to a 2026 animal nutrition study with 20 lambs, dietary supplementation with Tithonia diversifolia did not increase enteric methane production, indicating that the plant mixture could improve animal welfare without increasing environmental impact.
A 2026 study of 20 lambs in tropical conditions found that Tithonia diversifolia silage increased the abundance of Ruminococcus flavefaciens bacteria in the rumen, suggesting the plant promotes beneficial microbial populations in the digestive system.
The Quick Take
- What they studied: Whether feeding lambs a mixture of sugarcane and a tropical plant called Tithonia diversifolia would help them stay cooler and healthier in hot weather
- Who participated: Twenty young male lambs (crossbred Santa Inês and Dorper breeds), about 4 months old, weighing around 57 pounds each, raised in tropical conditions
- Key finding: Lambs eating the plant mixture had lower body temperatures and slower breathing rates compared to lambs eating only sugarcane, suggesting they were more comfortable in the heat
- What it means for you: Farmers in hot climates may be able to improve lamb health and comfort by mixing Tithonia diversifolia into their feed, though more research is needed to confirm long-term benefits
The Research Details
Scientists divided 20 young lambs into two equal groups. One group ate only sugarcane silage (a preserved grass food), while the other group ate a 50-50 mixture of sugarcane silage and Tithonia diversifolia silage (a tropical plant). Both groups received the same amount of grain and other nutrients. The researchers measured the lambs’ breathing rate, heart rate, and body temperature using both regular thermometers and special infrared cameras. They also collected air samples to measure how much methane gas the lambs produced and tested the bacteria living in the lambs’ stomachs.
This type of study is called a controlled experiment because the only major difference between the two groups was the type of plant in their feed. By keeping everything else the same, scientists could see if the plant mixture actually made a difference. The researchers used computer software to analyze all their measurements and determine if the differences between groups were real or just due to chance.
Understanding how different plants affect lamb health is important for farmers, especially in tropical regions where heat stress is a major problem. Heat stress makes animals uncomfortable, slows their growth, and can make them sick. If a simple change to their feed can help lambs stay cooler, it could improve both animal welfare and farm productivity. Additionally, methane production from livestock is a significant environmental concern, so finding feeds that don’t increase methane while improving animal comfort is valuable.
This study was published in a peer-reviewed journal, meaning other scientists reviewed it before publication. The sample size of 20 lambs is moderate—large enough to show clear differences but small enough that results should be confirmed with larger studies. The researchers used objective measurement tools (thermometers and gas collection equipment) rather than relying on observation alone. However, the study was conducted in one specific tropical location with one breed of lamb, so results may not apply everywhere or to all lamb types.
What the Results Show
Lambs fed the sugarcane-only diet showed significantly higher respiratory rates (faster breathing) and higher body temperatures on their skin and internal surfaces compared to lambs eating the plant mixture. This suggests that the Tithonia diversifolia addition helped the lambs’ bodies work less hard to stay cool. The difference was most noticeable in areas like the back, side, and rump of the lambs.
These findings are important because high body temperature and rapid breathing are signs that animals are experiencing heat stress. When animals are heat-stressed, they eat less, grow more slowly, and may become sick. By reducing these stress indicators, the plant mixture appears to help lambs cope better with hot weather.
The researchers also measured heart rate and other vital signs, and while some showed trends toward improvement in the plant mixture group, the differences weren’t large enough to be statistically significant. This means those changes could have happened by chance.
One interesting finding was that the bacteria in the lambs’ stomachs changed slightly based on diet. Specifically, a type of bacteria called Ruminococcus flavefaciens was more abundant in lambs eating the plant mixture. This suggests the Tithonia diversifolia plant may promote the growth of beneficial stomach bacteria. However, the researchers didn’t find major differences in overall bacterial populations or diversity between the two groups.
Contrary to expectations, both groups of lambs produced similar amounts of methane gas. This is actually good news because it means the plant mixture didn’t increase environmental impact while improving animal comfort.
Previous research has shown that tropical plants can help livestock stay cooler and reduce heat stress. This study adds to that body of knowledge by specifically testing Tithonia diversifolia with lambs in tropical conditions. The finding that methane production didn’t increase aligns with other research suggesting that plant-based feed changes can improve animal welfare without harming the environment. However, most previous studies focused on cattle rather than sheep, so this research fills an important gap.
The study only included 20 lambs, which is a relatively small number. A larger study would provide more confidence in the results. The research was conducted in one specific tropical location, so the results might be different in other climates or regions. The study only lasted for a specific period, so we don’t know if the benefits would continue long-term or if lambs would adapt over time. Additionally, the study used only one breed combination of lambs, so results might differ with other sheep breeds. Finally, the researchers didn’t measure whether the plant mixture affected how much the lambs grew or how much feed they ate, which are important practical concerns for farmers.
The Bottom Line
Based on this research, farmers in tropical regions may consider mixing Tithonia diversifolia silage with sugarcane silage at a 50-50 ratio to help reduce heat stress in lambs. The evidence is moderate in strength because the study was small and conducted in one location. Before making large-scale changes, farmers should test this approach on a small portion of their flock first. Consult with a veterinarian or animal nutritionist to ensure the diet meets all nutritional requirements for your specific situation.
This research is most relevant to sheep farmers in tropical and subtropical climates where heat stress is a regular problem. It may be particularly useful for farmers raising Santa Inês or Dorper breed lambs, though the principles might apply to other breeds. Farmers in temperate climates with mild summers may see less benefit. Environmental scientists and policymakers interested in reducing livestock methane emissions should also note that this approach didn’t increase methane production.
Based on the study design, the benefits to body temperature and breathing rate appeared within the timeframe of the experiment. However, the study didn’t measure growth rates or long-term health outcomes, so we don’t know how quickly farmers would see practical benefits like faster-growing lambs or improved survival rates. Expect to see changes in body temperature within days to weeks of dietary change, but allow several weeks to months to assess impacts on growth and overall health.
Frequently Asked Questions
Can adding Tithonia diversifolia to sheep feed help them stay cooler in hot weather?
Yes, a 2026 study of 20 lambs found that a 50-50 mixture of sugarcane and Tithonia diversifolia silage significantly reduced body temperature and respiratory rate compared to sugarcane alone, indicating improved heat tolerance in tropical climates.
Does Tithonia diversifolia increase methane production in sheep?
No, a 2026 research study found no significant differences in methane production between lambs fed Tithonia diversifolia mixture and those fed sugarcane alone, suggesting the plant provides heat stress benefits without increasing environmental impact.
What type of bacteria does Tithonia diversifolia promote in sheep stomachs?
A 2026 study found that Tithonia diversifolia silage increased Ruminococcus flavefaciens abundance in the rumen, a bacterium involved in fiber digestion, suggesting the plant promotes beneficial microbial populations.
How much Tithonia diversifolia should I feed my lambs?
The 2026 study used a 50-50 mixture of sugarcane and Tithonia diversifolia silage as the forage portion of the diet. Consult with a veterinarian or animal nutritionist to ensure proper nutritional balance for your specific flock and conditions.
Is Tithonia diversifolia safe for all sheep breeds?
The 2026 study tested crossbred Santa Inês and Dorper lambs. While results may apply to other breeds, the research is limited to one breed combination, so consult with a veterinarian before introducing it to different sheep types.
Want to Apply This Research?
- Track your lambs’ respiratory rate (breaths per minute) and body surface temperature weekly using a simple thermometer. Record these measurements at the same time each day to account for natural daily temperature variations. Compare measurements before and after introducing the plant mixture to see if your lambs show similar improvements to those in the study.
- If you’re a farmer, gradually introduce Tithonia diversifolia silage into your lambs’ diet over 7-10 days, starting at 25% of the forage portion and increasing to 50%. Monitor your lambs for any digestive changes or reduced feed intake. If you’re a researcher or student, use the app to log observations about animal behavior, feed consumption, and environmental conditions to build your own dataset.
- Establish a baseline of your current lambs’ vital signs and heat stress indicators before making dietary changes. After introducing the plant mixture, measure the same indicators weekly for at least 4-6 weeks. Track environmental temperature and humidity alongside animal measurements to account for weather variations. Document any changes in feed intake, growth rate, or health problems. Share your data with other farmers or researchers to build a larger evidence base.
This research describes findings from a single study with a small sample size (20 lambs) conducted in specific tropical conditions. Results may not apply to all climates, sheep breeds, or farming systems. Before making significant changes to your livestock feeding program, consult with a veterinarian, animal nutritionist, or agricultural extension specialist familiar with your local conditions. This information is for educational purposes and should not replace professional veterinary or agricultural advice. Individual results may vary based on factors including breed, age, health status, environmental conditions, and overall diet composition.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.