Modern meat chickens need more calcium and phosphorus than current feeding guidelines recommend to develop strong bones, according to a 2026 study of 360 broilers. Chickens fed higher mineral diets had 20% stronger bones by day 35 compared to those on lower mineral diets, even though muscle growth remained similar across all groups. This suggests that bone development is more sensitive to mineral availability than muscle growth, and that current nutritional models underestimate mineral requirements for fast-growing chickens.
According to Gram Research analysis, a new study found that modern chickens raised for meat need more calcium and phosphorus than current feeding guidelines recommend. Researchers fed 360 chickens different levels of these minerals and measured their bone strength and body composition. Chickens that received higher mineral levels had significantly stronger bones, while those on lower mineral diets developed weaker skeletal systems. This matters because chickens are bred to grow extremely fast, and their bones may not be keeping up with their muscle development. The findings suggest that current nutritional models underestimate how much calcium and phosphorus chickens actually need for healthy bone development.
Key Statistics
A 2026 study of 360 broiler chickens found that those fed low calcium and phosphorus diets had 20% weaker bones by day 35 compared to chickens fed high mineral diets, despite similar muscle growth across all groups.
Research showed that chickens fed moderate mineral diets had 14% weaker bones than those fed high mineral diets, indicating that even moderate mineral levels may be insufficient for optimal skeletal development in modern fast-growing breeds.
According to the 2026 broiler study, bone mineral content did not increase proportionally to body weight in chickens fed low and moderate mineral diets, but it did in those fed adequate minerals, suggesting mineral availability is a limiting factor for bone development.
The Quick Take
- What they studied: Whether chickens raised for meat need different amounts of calcium and phosphorus than current feeding guidelines recommend, and how these minerals affect bone strength versus muscle growth.
- Who participated: 360 Ross-308 broiler chickens (a common meat breed) divided into 10 groups, studied from hatching to 35 days old across three growth phases.
- Key finding: Chickens fed higher calcium and phosphorus diets had 20% stronger bones by day 35 compared to those fed lower mineral levels, while muscle growth remained similar across all groups.
- What it means for you: If you raise chickens or work in poultry farming, current feeding recommendations may not provide enough minerals for optimal bone health. This could reduce skeletal problems and improve overall chicken welfare, though more research is needed before changing industry standards.
The Research Details
Researchers divided 360 young chickens into groups and fed them three different diets over 35 days. One diet was low in calcium and phosphorus, one was moderate, and one was high. The high diet was designed using a mathematical model to maximize bone strength. The chickens were weighed regularly, and one bird from each group had its bones and body composition scanned using a special X-ray machine called dual-energy X-ray absorptiometry. This technology measures bone mineral content, muscle mass, and fat mass without harming the bird.
The study was divided into three phases: days 0 to 9, days 10 to 21, and days 22 to 35. This allowed researchers to see how mineral needs changed as chickens grew. They used statistical methods to predict how bone and muscle growth related to overall body weight, which helped them understand whether minerals were being used for bones or muscles.
Modern meat chickens grow incredibly fast due to selective breeding. This rapid growth may mean their bones cannot develop as quickly as their muscles, creating an imbalance. By testing different mineral levels, researchers could determine if current feeding guidelines are actually sufficient. Understanding the true mineral needs of fast-growing chickens helps ensure they develop healthy skeletons and reduces problems like lameness and bone fractures.
This study was well-designed with a reasonable sample size (360 birds) and multiple measurement points across the growing period. The use of X-ray scanning provides objective data rather than estimates. However, the study only tested one chicken breed and was conducted in controlled laboratory conditions, so results may not apply to all chicken types or farm environments. The study was published in a peer-reviewed scientific journal, which means other experts reviewed the methods and findings.
What the Results Show
At day 9, there were no major differences between the diet groups in bone strength or muscle growth. However, by day 21, chickens fed the high mineral diet showed a trend toward stronger bones. By day 35, the difference became clear: chickens fed low mineral diets had 20% weaker bones, and those fed moderate mineral diets had 14% weaker bones compared to the high mineral group.
Interestingly, muscle growth was similar across all groups, meaning the mineral-deficient chickens still gained muscle normally but failed to build strong bones. This suggests that when minerals are limited, the chicken’s body prioritizes muscle growth over bone strength. The researchers also found that bone mineral content did not increase proportionally to body weight in the low and moderate mineral groups, but it did in the high mineral group.
When researchers looked at how bone minerals related to protein (muscle) deposition, they found a clear pattern: as calcium and phosphorus decreased in the diet, bones became disproportionately weaker relative to muscle growth. This indicates that bone mineralization requires more minerals than current models assume.
The study found that daily bone mineral deposition (how much mineral was added to bones each day) tended to be higher in chickens fed the high mineral diet during the later growth phases. The relationship between bone strength and body weight also differed by diet: in chickens fed adequate minerals, bone strength increased proportionally with body weight, but in those fed lower minerals, this relationship was disrupted. This suggests that mineral availability is a limiting factor for bone development.
Current feeding guidelines for chickens assume that mineral deposition into bones is directly tied to protein (muscle) growth. This study challenges that assumption by showing that bone mineralization is more sensitive to dietary minerals than muscle growth is. Previous research has focused on preventing severe mineral deficiencies, but this study suggests that even moderate mineral levels may be insufficient for optimal bone health in modern fast-growing chickens. The findings align with concerns that genetic selection for rapid growth has outpaced skeletal development.
The study only tested one chicken breed (Ross-308), so results may not apply to other breeds or slower-growing chickens. All chickens were raised in controlled laboratory conditions with identical housing and management, which differs from commercial farms. The study lasted only 35 days, covering the main growth period but not the full lifespan of chickens. The researchers did not measure long-term outcomes like bone fracture rates or lameness in the field. Additionally, the study did not evaluate the cost-effectiveness of higher mineral diets for commercial producers.
The Bottom Line
Strong evidence suggests that calcium and phosphorus requirements for modern meat chickens should be higher than current guidelines recommend. Producers should consider increasing mineral levels, particularly during the later growth phases (days 22 to 35) when bone development is most active. However, implementation should be gradual and monitored, as this represents a change from established practices. Confidence in this recommendation is moderate to high based on this single well-designed study, but additional research across different breeds and farm conditions would strengthen the evidence.
Poultry producers, veterinarians, and feed manufacturers should pay attention to these findings. Chicken farmers concerned about skeletal health and bird welfare would benefit most. Consumers interested in animal welfare may also care about this research. However, backyard chicken keepers raising chickens for eggs rather than meat may not need to adjust their practices based on this study, as it focused on fast-growing meat breeds.
Bone strength differences became apparent by day 21 and were most pronounced by day 35. If producers adjust mineral levels, they should expect to see improvements in skeletal health within 2 to 3 weeks of the dietary change. Long-term benefits like reduced lameness and fractures would likely become evident over multiple flocks (several months to a year of production).
Frequently Asked Questions
Do chickens need more calcium and phosphorus than we currently feed them?
Research suggests yes. A 2026 study found that chickens fed higher mineral diets developed 20% stronger bones than those on standard diets, while muscle growth remained similar. Current feeding guidelines may underestimate mineral needs for modern fast-growing chicken breeds.
What happens to chicken bones when they don’t get enough calcium and phosphorus?
Bones become significantly weaker and do not develop proportionally to body weight. In the study, chickens on low mineral diets had 20% weaker bones by day 35, which could increase lameness and fracture risk during growth and processing.
Does increasing minerals affect how fast chickens grow or gain muscle?
No. The study found that muscle growth was similar across all mineral levels. Higher minerals specifically strengthened bones without changing overall growth rate, suggesting minerals and protein support different body systems.
When do chickens need the most calcium and phosphorus?
Bone mineral differences became most pronounced during weeks 3 to 5 of growth (days 22 to 35). This later growth phase appears most sensitive to mineral availability, suggesting higher mineral levels are especially important during this period.
Can weak bones from low minerals be fixed later in a chicken’s life?
The study did not address this question, as it only measured chickens to day 35. However, bone development is most active during early growth, suggesting that early mineral adequacy is important for long-term skeletal health.
Want to Apply This Research?
- Track daily feed mineral content (calcium and phosphorus levels in grams per kilogram) and correlate with weekly measurements of bird mobility, lameness incidents, and bone-related health issues. Record the percentage of birds showing signs of skeletal problems.
- If managing a flock, adjust feed formulations to increase calcium and phosphorus levels, particularly during weeks 3 to 5 of growth. Document the specific mineral concentrations used and monitor bird behavior for signs of improved mobility and reduced lameness compared to previous flocks.
- Establish a baseline of skeletal health problems in your current flock, then implement higher mineral diets and track changes over 2 to 3 production cycles. Monitor for lameness, mobility issues, and bone-related culling. Consider periodic bone density assessments if equipment is available, or work with a veterinarian to evaluate skeletal health.
This research applies specifically to fast-growing meat chicken breeds (broilers) studied in controlled laboratory conditions. Results may not apply to other chicken breeds, slower-growing birds, or backyard flocks. Before making changes to chicken feed or management practices, consult with a veterinarian or poultry nutritionist familiar with your specific situation. This study represents one research trial and should not be considered definitive industry guidance without additional supporting research. Always follow local regulations and best practices for animal care.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.