Researchers tested whether adding ground walnut shells to lamb feed could help the animals grow better and digest their food more efficiently. They fed one group of lambs regular food and another group the same food with 1% walnut shell powder mixed in for 60 days. The lambs eating the walnut shell food ended up slightly heavier and digested their fiber much better, even though they didn’t eat more or gain weight faster. This discovery is exciting because it shows we can turn agricultural waste into something useful for animal farming while also helping the environment.

The Quick Take

  • What they studied: Whether adding powdered walnut shells to lamb feed would improve how well the lambs grew and how efficiently their bodies used the food
  • Who participated: 12 young male lambs that weighed about 76 pounds at the start of the study, divided into two equal groups
  • Key finding: Lambs that ate food with 1% walnut shell powder ended up about 2-3 pounds heavier than lambs eating regular food, and their bodies broke down tough plant fibers much better (about 10-15% more efficient)
  • What it means for you: If you raise sheep or lambs, adding walnut shell powder to their feed might help them gain a bit more weight and digest their food better. However, this was a small study, so farmers should test it themselves before making big changes. The effect is modest but promising.

The Research Details

Scientists took 12 young lambs and randomly split them into two groups of 6. One group ate normal feed, while the other group ate the same feed but with 1% walnut shell powder added to it. They fed both groups this way for 60 days (about 2 months) and carefully measured how much the lambs ate, how much weight they gained, and what happened inside their stomachs. The researchers also tested the lambs’ poop to see how well they were digesting their food, and they collected samples from inside the lambs’ stomachs to study how food was being broken down.

This type of study is called a controlled experiment because the researchers kept everything the same between the two groups except for the walnut shell powder. This helps them figure out if the walnut shells actually made a difference or if any changes would have happened anyway.

Understanding how different feed additives affect animals is important for farmers who want to raise healthier, more efficient livestock. It’s also valuable because walnut shells are normally thrown away, so using them as animal feed helps reduce waste and protects the environment. This study shows a practical way to recycle agricultural waste into something useful.

This was a small study with only 12 lambs, which means the results might not apply to all lambs everywhere. The researchers did use proper scientific methods by randomly assigning lambs to groups and carefully measuring their results. However, because it’s a small study, the findings should be confirmed with larger groups of lambs before farmers make major changes. The study lasted only 60 days, so we don’t know if the benefits would continue longer.

What the Results Show

The most important finding was that lambs eating walnut shell powder ended up weighing slightly more (about 5% heavier) than lambs eating regular food. However, this difference was just barely statistically significant, meaning it could have happened by chance. Interestingly, the lambs didn’t eat more food or gain weight faster day-by-day—they just ended up slightly heavier overall.

The really exciting finding was about digestion. Lambs eating the walnut shell powder digested their food much better. They broke down tough plant fibers (the parts of plants that are hard to digest) about 10-15% more efficiently than lambs eating regular food. This means their bodies were getting more nutrition from the same amount of food.

Inside the lambs’ stomachs, the walnut shells changed how food was being broken down in interesting ways. The lambs eating walnut shells had higher levels of a substance called propionate, which is actually good for their health. They also had fewer tiny organisms called protozoa in their stomachs, which suggests the walnut shells were changing the balance of microbes in a beneficial way.

The study found that walnut shells didn’t change several other important measurements. The lambs’ stomach acid levels stayed the same, and the amount of ammonia in their stomachs didn’t change. This is good news because it means the walnut shells weren’t causing any negative effects on these important digestive processes.

This research fits with other studies showing that biochar (charred plant material) can help animals digest food better. Previous research on other animals and other types of biochar has shown similar improvements in fiber digestion. However, this is one of the first studies specifically looking at walnut shell biochar in lambs, so it adds new information to what scientists already know about using agricultural waste to improve animal nutrition.

The biggest limitation is that only 12 lambs were studied, which is a small number. With such a small group, some of the results might have happened by chance. The study only lasted 60 days, so we don’t know if the benefits would continue if lambs ate this feed for months or years. The study was done in a controlled laboratory setting, so results might be different on actual farms with different conditions. Finally, the researchers didn’t test different amounts of walnut shell powder—they only tried 1%—so we don’t know if more or less would work better.

The Bottom Line

Based on this research, walnut shell powder may be worth trying as a feed additive for lambs, but with moderate confidence. The evidence suggests it helps with digestion and might lead to slightly better growth. However, farmers should start with small amounts and monitor their lambs carefully. This is not a proven treatment yet—it’s a promising idea that needs more testing. Consult with a veterinarian or animal nutrition expert before making changes to your animals’ feed.

Sheep and lamb farmers might be interested in this research, especially those looking for ways to improve their animals’ digestion or reduce feed costs. Environmental advocates might appreciate using agricultural waste productively. However, this research is too early-stage for most farmers to rely on it as a major feeding strategy. People who don’t raise livestock don’t need to worry about this research.

If a farmer decided to try walnut shell powder, they might see changes in digestion within a few weeks, similar to this 60-day study. However, any weight gain benefits would be modest—probably just a few extra pounds over two months. It would take several months of feeding to know if this works well for a specific farm’s conditions.

Want to Apply This Research?

  • If tracking livestock nutrition, users could log weekly body weight measurements and note any changes in digestion quality or feed efficiency when walnut shell biochar is added to feed
  • A farmer using a livestock management app could set a reminder to weigh animals weekly and track feed intake amounts to monitor the actual impact of adding walnut shell powder to their specific herd
  • Over 8-12 weeks, track average daily weight gain, total feed consumed, and visual digestive health indicators to determine if walnut shell biochar is worth continuing on your farm

This research is preliminary and based on a small study of 12 lambs. The findings suggest walnut shell biochar may improve digestion in lambs, but more research is needed before widespread adoption. Farmers should consult with a veterinarian or animal nutritionist before making significant changes to their animals’ feed. This information is for educational purposes and should not replace professional agricultural or veterinary advice. Individual results may vary based on farm conditions, lamb breeds, and other factors.