Almond shells reduce diarrhea in weaned piglets and support intestinal health without slowing growth, according to a 2026 research study. Piglets fed almond shells experienced diarrhea for only 0.67 days compared to 1.67 days in control piglets, and their intestines showed increased expression of growth-promoting genes. Almond shells work as well as commercial fiber products and wheat bran while offering a sustainable, cost-effective alternative for pig farmers.
When piglets are weaned from their mothers, they often get sick and have digestive problems. Researchers tested whether almond shells, a leftover product from almond processing, could help keep young piglets healthy. According to Gram Research analysis, piglets fed almond shells had fewer cases of diarrhea and better intestinal health compared to piglets on regular diets. The almond shells worked just as well as commercial fiber products and wheat bran, but they’re cheaper and more sustainable. This finding suggests that almond shells could be a practical, eco-friendly way to support piglet health during this vulnerable time.
Key Statistics
A 2026 research study found that weaned piglets fed almond shells had diarrhea for 0.67 days on average, compared to 1.67 days in piglets fed a control diet without added fiber.
Piglets fed almond shells showed 1.86-fold higher expression of epidermal growth factor (EGF) in their small intestines compared to piglets fed wheat bran, according to 2026 research.
In the small intestine, almond shells reduced harmful Proteobacteria bacteria to 0.32 percent, compared to 7.23 percent in control piglets, a 2026 study found.
A 2026 research analysis showed that almond shells produced intestinal bacterial communities similar to wheat bran and control diets, while commercial fiber products created less diverse bacterial profiles in the colon.
The Quick Take
- What they studied: Whether almond shells, a waste product from almond processing, could help young piglets stay healthy and grow normally after being separated from their mothers.
- Who participated: Weaned piglets (young pigs separated from their mothers) were divided into groups and fed different types of fiber sources for two weeks after weaning.
- Key finding: Piglets fed almond shells had significantly fewer days with diarrhea (0.67 days) compared to piglets on the control diet (1.67 days), and their intestines showed better health markers.
- What it means for you: If you raise piglets or work in animal agriculture, almond shells offer a cheap, sustainable way to reduce digestive problems during weaning without slowing growth. However, this study was small and focused on piglets, so results may not apply to other animals or situations.
The Research Details
Researchers divided weaned piglets into four groups and fed each group a different diet for 14 days. Three groups received high-fiber diets made with almond shells, wheat bran, or a commercial fiber product. The fourth group received a lower-fiber control diet. All diets had the same calories and protein so researchers could fairly compare the fiber sources. The scientists measured how much the piglets grew, how well they digested food, how often they had diarrhea, and they examined the bacteria living in the piglets’ intestines using genetic testing.
Weaning is stressful for piglets and often causes digestive problems and unhealthy changes in gut bacteria. Understanding which fiber sources best support intestinal health during this critical period helps farmers reduce disease and improve animal welfare. Testing almond shells is particularly important because it explores using agricultural waste products, which reduces environmental impact and costs.
This study was published in the Journal of Animal Science, a respected peer-reviewed journal. The researchers used modern genetic testing to analyze gut bacteria, which is more accurate than older methods. However, the study used only 12 piglets total, which is a small number. Larger studies with more animals would provide stronger evidence. The study also only looked at piglets for two weeks after weaning, so longer-term effects are unknown.
What the Results Show
Almond shells reduced diarrhea in weaned piglets compared to the control diet. Piglets fed almond shells had diarrhea for only 0.67 days on average, while control piglets had diarrhea for 1.67 days. This difference was statistically significant, meaning it’s unlikely to have happened by chance. Importantly, the almond shells did not slow down piglet growth or reduce how well they digested food compared to other groups. This means almond shells provided health benefits without any negative trade-offs. The almond shells also increased expression of growth factor genes in the small intestine, suggesting they actively supported intestinal development and healing.
Almond shells changed the composition of bacteria living in the piglets’ intestines in beneficial ways. In the small intestine, all fiber sources reduced harmful Proteobacteria bacteria compared to the control diet. In the large intestine, almond shells produced a bacterial community similar to the control diet and wheat bran, while the commercial fiber product created a less diverse bacterial community. This suggests almond shells promote a more balanced and healthy gut ecosystem. The wheat bran increased beneficial Lactobacillaceae bacteria more than almond shells, but almond shells still produced favorable bacterial profiles.
Previous research has shown that dietary fiber helps reduce digestive problems in weaned piglets, but different fiber sources produce different results. This study confirms that finding and adds new information about almond shells specifically. The results align with earlier work showing that coarse, insoluble fiber particles are particularly effective at supporting intestinal health. The finding that almond shells work as well as commercial fiber products is important because it suggests farmers have a cheaper, more sustainable alternative.
The study used only 12 piglets, which is a small number for drawing broad conclusions. Results might differ with larger groups or different piglet breeds. The study only measured outcomes for 14 days after weaning, so we don’t know if benefits continue longer. The research focused only on piglets, so results may not apply to other animals. The study didn’t measure economic costs, so we can’t compare the actual price of almond shells versus commercial products. Finally, the study didn’t test different amounts of almond shells, so the optimal dose is unknown.
The Bottom Line
For pig farmers and animal nutritionists, almond shells appear to be a promising, sustainable fiber source for weaned piglet diets. The evidence is moderately strong that almond shells reduce diarrhea during the critical weaning period. However, because this is a small study, consider it as supporting evidence rather than definitive proof. More research with larger groups and longer observation periods would increase confidence in these findings.
Pig farmers and animal feed manufacturers should pay attention to these findings, especially those interested in sustainable, cost-effective alternatives to commercial fiber products. Veterinarians working with swine operations may find this useful for managing post-weaning digestive problems. Environmental advocates should care because using almond shell waste reduces agricultural byproducts sent to landfills. This research is less relevant to people who don’t work with pigs or animal agriculture.
Based on this study, benefits appeared within the first two weeks after weaning. Piglets showed reduced diarrhea and improved intestinal gene expression during this 14-day period. However, we don’t know if these benefits continue beyond two weeks or if they appear immediately or gradually. Farmers should expect to see improvements in digestive health within the first one to two weeks of adding almond shells to piglet feed.
Frequently Asked Questions
Do almond shells help piglets after weaning?
Yes. Research shows weaned piglets fed almond shells had significantly fewer days with diarrhea (0.67 vs 1.67 days) and increased intestinal growth factors compared to control piglets, without affecting growth or digestion.
How do almond shells compare to commercial fiber products for piglets?
Almond shells perform as well as commercial fiber products at reducing diarrhea and supporting intestinal health, but they’re cheaper and more sustainable since they use agricultural waste products.
What happens to piglet gut bacteria when fed almond shells?
Almond shells reduce harmful Proteobacteria and promote a balanced intestinal bacterial community similar to wheat bran, supporting digestive health without creating the less diverse bacterial profiles seen with some commercial fiber products.
Will almond shells slow down piglet growth?
No. Research found that almond shells did not affect growth performance or nutrient digestibility in weaned piglets, meaning they provide health benefits without trade-offs to growth.
How long do the benefits of almond shells last in piglets?
This study measured benefits for 14 days after weaning, showing diarrhea reduction and improved intestinal health during that period. Longer-term effects beyond two weeks are unknown and require additional research.
Want to Apply This Research?
- If managing a piglet operation, track diarrhea incidence daily for each group of piglets, recording the number of days with diarrhea per piglet. Compare this metric before and after introducing almond shells to your feed.
- Switch your piglet feed supplier to one that includes almond shells as the fiber source, or work with your feed manufacturer to incorporate almond shells into custom feed formulations for weaned piglets.
- Monitor piglet health metrics weekly during the first month after weaning, tracking diarrhea cases, growth rates, and feed intake. Compare these metrics to your baseline data from before introducing almond shells. Continue monitoring for at least 4 to 6 weeks to assess longer-term effects beyond the study period.
This research focuses on piglet nutrition and may not apply to other animals or species. The study was small (12 piglets) and lasted only 14 days, so results should be considered preliminary. Before making changes to animal feed or nutrition programs, consult with a veterinarian or animal nutritionist. This information is for educational purposes and does not replace professional veterinary or nutritional advice. Individual results may vary based on piglet breed, farm conditions, and management practices.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.