Researchers tested whether adding walnut meal (a byproduct from walnut oil production) to chicken feed could be a cheaper alternative to traditional feed ingredients while potentially improving the nutritional quality of chicken meat. They fed different groups of chickens diets containing 0%, 2.5%, 5%, 7.5%, or 10% walnut meal and measured how well the chickens grew and analyzed the fat and protein content of their meat. The study found that adding up to 7.5% walnut meal didn’t harm chicken growth or meat quality, and it actually improved the healthy fat profile of the meat. However, adding too much (10%) slowed down chicken growth slightly.

The Quick Take

  • What they studied: Whether feeding chickens walnut meal instead of traditional feed ingredients would keep them healthy while making their meat more nutritious
  • Who participated: Ross 308 broiler chickens (a common meat chicken breed) divided into groups receiving different amounts of walnut meal in their feed
  • Key finding: Chickens fed up to 7.5% walnut meal grew normally and produced meat with better healthy fat profiles, but chickens fed 10% walnut meal grew slightly slower
  • What it means for you: Chicken meat produced with walnut meal supplementation may contain more beneficial fats, though this is primarily relevant to farmers and food producers deciding what to feed their chickens

The Research Details

Researchers divided broiler chickens into five groups and fed each group a different diet. One group received standard feed (the control group), while the other four groups received feed containing 2.5%, 5%, 7.5%, or 10% walnut meal mixed in. They raised all the chickens under the same conditions and measured how much they ate, how much they grew, and how much they weighed at the end. They also analyzed the meat from the chickens’ thighs to measure the types of fats and proteins present.

This type of study is called a dose-response experiment because researchers tested multiple amounts (doses) of the same ingredient to find the best level. By testing several different percentages, they could determine whether more walnut meal was always better, or if there was an optimal amount.

This research approach is important because it helps farmers and feed manufacturers make practical decisions about ingredient substitution. Rather than just testing whether walnut meal works at all, the researchers tested multiple levels to find the sweet spot where the feed is economical but doesn’t harm chicken health or meat quality. This real-world testing is more useful than laboratory studies alone.

The study was published in a peer-reviewed scientific journal, meaning other experts reviewed the research before publication. The researchers measured multiple important outcomes (growth, meat quality, fat composition) rather than just one thing. However, the specific number of chickens used in the study was not clearly stated in the abstract, which makes it harder to assess how reliable the results are. The study focused on one chicken breed, so results might differ with other breeds.

What the Results Show

When chickens ate feed containing up to 7.5% walnut meal, they grew normally and gained weight at typical rates. Their meat quality remained good, and the carcass weight (total meat weight) was similar to chickens eating standard feed. This suggests that moderate amounts of walnut meal can be used as a feed ingredient without harming chicken production.

At the highest level tested (10% walnut meal), chickens grew slightly slower and gained less weight. Their feed conversion ratio—a measure of how efficiently they convert feed into body weight—also worsened. This indicates that too much walnut meal may be counterproductive.

The most interesting finding involved the fat composition of the meat. Meat from chickens fed walnut meal contained higher levels of healthy unsaturated fats and omega-3 fatty acids compared to the control group. These are the types of fats that nutritionists generally recommend for human health. The ratio of healthy to unhealthy fats improved in the walnut meal groups.

The amino acid profile (the building blocks of protein) in the chicken meat remained unchanged regardless of walnut meal inclusion. This is good news because it means the nutritional protein quality of the meat wasn’t compromised. Some slaughter characteristics (like how much of the bird is usable meat) were unaffected by walnut meal inclusion, suggesting the meat quality remained consistent.

This research builds on previous studies showing that alternative feed ingredients can sometimes improve meat quality while reducing costs. The finding that walnut meal improves fat composition aligns with what scientists know about walnuts being rich in healthy fats. However, this appears to be one of the first studies specifically examining walnut meal in broiler chicken diets at multiple inclusion levels, making it a novel contribution to agricultural nutrition research.

The study only tested one breed of chicken (Ross 308), so results may not apply to other chicken breeds or types of poultry. The abstract doesn’t specify the exact number of chickens used, making it difficult to assess statistical power. The study measured only thigh meat composition; other parts of the chicken might respond differently. The research was conducted under controlled farm conditions, which may not reflect all real-world farming scenarios. Long-term effects of walnut meal feeding were not examined.

The Bottom Line

Based on this research, farmers could consider including walnut meal at 2.5% to 7.5% in broiler chicken feed as a cost-effective alternative ingredient. The evidence suggests 2.5% may offer the best balance between economic benefit and performance. However, avoid exceeding 10% walnut meal, as this appears to negatively impact chicken growth. Confidence level: Moderate (limited to one chicken breed and one study).

This research is most relevant to poultry farmers, feed manufacturers, and agricultural economists looking to reduce feed costs while maintaining or improving meat quality. It may also interest consumers concerned about the nutritional quality of chicken meat. This research is less directly relevant to home cooks or individual consumers, though it could eventually influence the chicken products available in stores.

Changes in meat fat composition would occur throughout the chicken’s growth period (typically 6-7 weeks for broilers). Farmers would see economic benefits from reduced feed costs immediately upon switching ingredients. Consumers would receive the nutritional benefits of improved fat composition with every chicken meal, though individual health benefits would depend on overall diet and consumption patterns.

Want to Apply This Research?

  • For farmers using the app: Track weekly feed costs and chicken weight gain when switching to walnut meal inclusion at 2.5-7.5% levels. Compare cost per pound of meat gained versus standard feed to quantify economic savings.
  • Farmers could use the app to set reminders for gradual feed transitions when introducing walnut meal, ensuring chickens adjust properly to the new ingredient. They could also log batch performance data to identify optimal walnut meal percentages for their specific operation.
  • Establish a baseline of current feed costs and chicken performance metrics. After switching to walnut meal-supplemented feed, track the same metrics weekly for at least one full production cycle (6-7 weeks). Compare results to identify cost savings and any performance changes, adjusting walnut meal percentage based on results.

This research applies to commercial poultry production and feed formulation decisions made by farmers and feed manufacturers. Individual consumers should not attempt to modify chicken diets without professional agricultural guidance. While the study suggests improved fat composition in meat from walnut meal-fed chickens, consumers should not consider this a substitute for medical advice or dietary recommendations from healthcare providers. Results are specific to the Ross 308 broiler breed and may not apply to other poultry types. Consult with a veterinarian or animal nutritionist before making significant changes to poultry feed formulations.