Adding butterfly pea hay to corn silage significantly increases how much lambs eat and improves their final meat weight, according to a 2026 research study of 20 lambs. Lambs fed the butterfly pea hay combination showed better protein digestion and heavier carcasses at processing compared to lambs without the hay. Keeping corn cobs in the feed also improved starch digestion and water balance. Gram Research analysis shows this tropical plant could help farmers produce more meat efficiently using locally available feed sources.
Researchers tested whether adding butterfly pea hay to corn feed could help lambs grow better. They fed 20 young lambs different combinations of corn silage with and without corn cobs, some mixed with butterfly pea hay. According to Gram Research analysis, lambs that ate the butterfly pea hay combination ate more food, digested nutrients better, and ended up with heavier meat when processed. The study shows that this colorful plant could be a practical way to improve lamb farming in tropical areas where it grows naturally.
Key Statistics
A 2026 study of 20 lambs found that adding butterfly pea hay to corn silage increased dry matter intake with statistical significance (P less than 0.001) and improved crude protein digestibility (P equals 0.006).
Lambs fed butterfly pea hay had significantly heavier hot carcass weight (P equals 0.011) and cold carcass weight (P equals 0.009) compared to lambs without the hay in a 2026 controlled feeding trial.
Corn cobs in lamb feed improved starch digestibility (P equals 0.015) and enhanced water balance (P equals 0.021) while increasing hot carcass yield (P equals 0.021) in a 2026 research study.
A 2026 trial with 20 lambs showed that butterfly pea hay inclusion increased nitrogen absorption (P equals 0.006), a key nutrient for muscle development and meat production.
The Quick Take
- What they studied: Whether adding butterfly pea hay (a nutritious plant) to corn-based animal feed would help lambs eat more, digest food better, and grow larger.
- Who participated: Twenty young male lambs weighing about 18 kilograms each were divided into four groups and fed different combinations of corn silage with or without corn cobs, some mixed with butterfly pea hay.
- Key finding: Lambs fed butterfly pea hay ate significantly more food and had heavier carcasses at processing compared to lambs without the hay. Corn cobs in the feed also improved how well the lambs digested starch and maintained water balance.
- What it means for you: Farmers raising lambs in warm climates could use butterfly pea hay as an affordable, natural way to improve animal nutrition and meat production. This approach uses locally available plants, making farming more sustainable and cost-effective.
The Research Details
Scientists conducted a controlled feeding experiment with 20 young lambs divided into four equal groups. Each group received a different diet: corn silage with cobs, corn silage with cobs plus butterfly pea hay, corn silage without cobs, or corn silage without cobs plus butterfly pea hay. The lambs were randomly assigned to groups and the experiment was designed so that researchers could measure the separate effects of both the corn cobs and the butterfly pea hay. Researchers carefully measured how much each lamb ate, how well they digested their food, their water and nitrogen balance, and the weight and quality of their meat after processing.
This research design allowed scientists to test two variables at once: whether corn cobs matter and whether butterfly pea hay matters. By using a controlled experiment with random assignment, the researchers could be confident that any differences between groups came from the feed itself, not from other factors like age or genetics. Measuring multiple outcomes like food intake, digestion, and final meat weight gives a complete picture of how the feed affects the whole animal.
The study used a randomized design with five replicate animals per treatment group, which strengthens confidence in the results. The researchers measured multiple important outcomes including nutrient digestibility and carcass characteristics. However, the study involved only 20 lambs total, which is a relatively small number. The research was published in a peer-reviewed journal, meaning other experts reviewed the methods and findings before publication. Results with very low P-values (like P less than 0.001) indicate strong statistical evidence, while the numerical increase in daily weight gain (P equals 0.062) suggests a trend that didn’t quite reach statistical significance.
What the Results Show
Lambs that received butterfly pea hay in their diet ate significantly more dry matter (the solid nutrients in feed) compared to lambs without the hay. This increased food intake was statistically significant, meaning it was a real effect and not due to chance. Additionally, these lambs showed better digestion of crude protein (the main nutrient for building muscle) and absorbed more nitrogen, which is essential for growth. The most practical result was that lambs fed butterfly pea hay had heavier carcasses both when freshly processed (hot carcass weight) and after cooling (cold carcass weight), with differences that were statistically significant. Corn cobs in the feed improved how well lambs digested starch, the main energy source in corn, and helped them maintain better water balance in their bodies. Corn cobs also increased the percentage of carcass weight relative to total body weight, meaning more of the lamb’s weight was usable meat.
While lambs fed butterfly pea hay showed a numerical increase in average daily weight gain, this difference was not statistically significant, though it approached significance. This suggests the hay may help with growth, but the effect on daily weight gain was not as clear as the effects on food intake and final carcass weight. The combination of improved nutrient digestion and increased food intake likely explains why the lambs had heavier carcasses despite not showing a dramatic increase in daily growth rate.
This research builds on previous studies showing that legume hays (plants in the pea family) can improve animal nutrition. Butterfly pea is a tropical plant that grows well in warm climates and has been used in traditional farming. This study is among the first to systematically test butterfly pea hay combined with modern corn silage feeding systems. The findings align with general knowledge that adding protein-rich plants to grain-based diets improves nutrient utilization in livestock.
The study involved only 20 lambs, which is a small number for drawing broad conclusions. The research was conducted in one location under specific conditions, so results may differ in other climates or farming systems. The study did not measure the cost of butterfly pea hay compared to other feed options, so farmers would need additional information to decide if it is economically worthwhile. The lambs were all young males of similar weight, so the results may not apply to older lambs, females, or different breeds. The study did not test butterfly pea hay at different inclusion levels, so the optimal amount to add to feed is unknown.
The Bottom Line
Farmers in tropical regions who raise lambs should consider adding butterfly pea hay to corn silage-based diets to improve meat production. The evidence is moderately strong that this approach increases food intake and final carcass weight. Farmers should also maintain corn cobs in their silage to improve starch digestion and water balance. These recommendations are most confident for young male lambs similar to those in the study. Before making large-scale changes, farmers should test the approach on a small scale and compare costs with their current feeding system.
Lamb farmers in tropical and subtropical regions where butterfly pea grows naturally should pay attention to these findings. The approach is most relevant for farmers using corn silage as a base feed and looking to improve meat production efficiency. Farmers in cooler climates may find butterfly pea hay harder to grow or source. This research is less directly applicable to sheep farmers raising animals for wool or breeding rather than meat production.
Farmers would likely see improved food intake within days of adding butterfly pea hay to the feed, as animals typically adjust to new foods quickly. Improvements in carcass weight would become apparent over weeks to months of feeding, depending on how long lambs are raised before processing. The study did not specify the exact length of the feeding period, but typical lamb fattening takes 8 to 12 weeks.
Frequently Asked Questions
Does butterfly pea hay help lambs grow faster and produce more meat?
Research shows butterfly pea hay increases food intake and final carcass weight in lambs. While daily weight gain showed a numerical increase, it was not statistically significant. The heavier final carcasses suggest improved overall meat production efficiency.
What is butterfly pea and where does it grow?
Butterfly pea (Clitoria ternatea L.) is a legume plant that grows naturally in tropical and subtropical regions. It produces nutritious hay rich in protein and is used in traditional farming systems. The plant thrives in warm climates where corn also grows well.
Should farmers keep corn cobs in silage or remove them?
Research indicates keeping corn cobs in silage improves starch digestion and water balance in lambs. Cobs also increased the percentage of usable meat relative to total body weight, suggesting they should be retained rather than removed from the feed.
How much butterfly pea hay should be added to lamb feed?
The study did not test different inclusion levels of butterfly pea hay, so the optimal amount is unknown. Farmers should start with small amounts (10 to 20 percent of total hay) and monitor lamb response before increasing the proportion based on their results.
Is butterfly pea hay suitable for all types of sheep and lambs?
This research tested only young male lambs of similar weight and age. Results may differ for older sheep, females, different breeds, or sheep raised for wool rather than meat. Farmers should test the approach on a small scale before making large changes.
Want to Apply This Research?
- Track daily feed consumption per lamb and weekly body weight measurements. Record the percentage of butterfly pea hay in the diet and monitor changes in feed intake and growth rate over 4-week intervals.
- If you manage a farm, start by replacing 10 to 20 percent of your regular hay with butterfly pea hay in your corn silage mix. Observe how your lambs respond over two to three weeks before increasing the proportion. Keep detailed records of feed costs and meat quality to determine if the change is economically beneficial for your operation.
- Establish a baseline of current feed intake and carcass weights before making changes. After introducing butterfly pea hay, measure the same metrics weekly for at least 8 weeks. Compare the cost per kilogram of meat produced before and after the dietary change. Track any changes in animal health or digestion issues. Adjust the proportion of butterfly pea hay based on your results and local availability.
This research describes results from a controlled study with 20 lambs and may not apply to all farming conditions, breeds, or climates. Farmers should consult with local agricultural extension services or veterinarians before making significant changes to animal feeding programs. The study did not evaluate long-term health effects or economic feasibility for specific farming operations. Results are specific to the conditions tested and may vary based on local feed availability, climate, and animal genetics. Always introduce new feed ingredients gradually and monitor animal health and performance.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.