Researchers studied how the intestines of Cobb 500 broiler chickens develop during their first month of life. They measured different parts of the intestines at birth and at weeks 1, 2, 3, and 4 to understand how these organs grow and become better at absorbing nutrients. The study found that intestinal structures grow steadily during this critical period, with some parts growing faster than others. Understanding this natural development helps farmers and scientists figure out the best ways to feed young chickens for healthy growth.

The Quick Take

  • What they studied: How the small intestines of young broiler chickens grow and develop during their first four weeks of life, and whether different parts of the intestines grow at different rates.
  • Who participated: 128 Cobb 500 broiler chickens (a common breed raised for meat) divided into 16 groups of 8 birds each, studied from birth through 28 days old.
  • Key finding: The intestines show steady, organized growth during the first four weeks. The upper part of the small intestine (jejunum) develops faster and becomes better at absorbing nutrients than the lower part (ileum). Growth happens in a predictable pattern that researchers can now measure and track.
  • What it means for you: This research provides a roadmap for understanding normal chicken intestinal development. While this is primarily useful for poultry farmers and nutritionists, it may eventually help improve feeding strategies to support healthier, faster-growing chickens. The findings suggest that feeding young chickens differently at different ages might be beneficial, but more research is needed to confirm this.

The Research Details

Researchers raised 128 young broiler chickens in controlled conditions and measured their intestines at five different time points: at birth (day 0) and at weeks 1, 2, 3, and 4. They took tissue samples from the jejunum (upper small intestine) and ileum (lower small intestine) from one bird per group at each time point. They then examined these tissues under a microscope to measure specific structures like the height of finger-like projections (villi) that help absorb nutrients, the depth of the pockets between these projections (crypts), and the overall size of these structures.

The researchers used a statistical method that allowed them to look at two main factors: how age affected intestinal development and whether the upper and lower parts of the intestine developed differently. This approach helped them identify patterns in how the intestines matured over time.

This type of study is called a cross-sectional study because it takes snapshots of the intestines at different ages rather than following the same birds throughout the entire period. This approach is efficient and provides clear information about what normal development looks like at each stage.

Understanding how chicken intestines naturally develop is important because the intestines are where nutrients from food get absorbed into the body. Better-developed intestines with larger surface areas can absorb more nutrients, which helps chickens grow faster and healthier. By establishing what normal development looks like, researchers create a baseline that can be used to test whether different feeding strategies, supplements, or management practices improve intestinal development beyond what naturally occurs.

This study has several strengths: it used a large sample size (128 birds), measured multiple aspects of intestinal structure, and examined both the upper and lower small intestine. The researchers used proper statistical methods to analyze their data. However, the study only looked at one breed of chicken (Cobb 500), so results may not apply to other chicken breeds. The study also didn’t test any interventions or compare different feeding strategies—it simply documented what happens naturally. Additionally, the study measured intestines at specific time points rather than continuously, so some details about the exact timing of changes were not captured.

What the Results Show

The intestines showed steady, predictable growth from birth through day 28. The finger-like projections (villi) that absorb nutrients grew taller, wider, and larger throughout the four-week period. The upper part of the small intestine (jejunum) had taller villi and larger absorptive surfaces compared to the lower part (ileum), suggesting it plays a more important role in nutrient absorption.

Interestingly, some measurements showed a curved growth pattern rather than straight-line growth. For example, the width of the villi at the base and middle increased quickly at first, then the rate of increase slowed down. The pockets between villi (crypts) also showed this curved pattern, getting deeper quickly early on, then more slowly later.

The ratio between villus height and crypt depth (a measure of intestinal health and function) was higher in the jejunum than the ileum, and this ratio improved with age. This suggests the upper intestine becomes increasingly efficient at absorbing nutrients as the chicken grows.

All the different measurements of intestinal structure were strongly related to each other, meaning that when one part grew, the others grew proportionally. This coordinated growth suggests the intestine develops in a balanced, organized way.

The total size of the intestinal cross-section (the area you’d see if you cut the intestine in half) increased with age, and the perimeter (the distance around the intestine) also grew. These measurements confirm that the entire intestinal tube expands as the chicken grows. Interestingly, the intestines grew more slowly than the chicken’s overall body weight from week 1 to week 4, suggesting that while intestinal development is important early on, body growth eventually outpaces intestinal growth. This finding is important because it suggests that intestinal capacity may become a limiting factor for nutrient absorption in very rapidly growing chickens.

This study provides detailed measurements of normal intestinal development in Cobb 500 broilers, which is one of the most common meat chicken breeds. While other studies have looked at chicken intestinal development, this research offers a comprehensive picture of how multiple intestinal structures change together over the critical first four weeks. The finding that the jejunum develops faster than the ileum aligns with what researchers have observed in other poultry species and mammals, suggesting this is a fundamental pattern in how intestines develop. The coordinated growth pattern observed here provides a useful reference point for future studies testing whether specific feeding strategies or supplements can enhance this natural development.

This study only examined one chicken breed (Cobb 500), so the results may not apply to other breeds or types of poultry. The research measured intestines at only five specific time points, so the exact timing of changes between these points is unknown. The study did not test any interventions or compare different feeding strategies—it simply documented natural development. Additionally, the study measured intestines from different birds at each time point rather than following the same birds throughout, which means individual variation between birds wasn’t accounted for. Finally, the study was conducted in a controlled research setting, so results might differ in commercial farming conditions with different management practices or environmental factors.

The Bottom Line

For poultry farmers and nutritionists: This research provides a baseline for understanding normal intestinal development in Cobb 500 broilers. It suggests that the first four weeks of life are critical for intestinal maturation, and that feeding strategies might be optimized based on age-specific intestinal development. However, the study itself doesn’t test specific feeding recommendations, so farmers should consult with poultry nutritionists about how to apply these findings. The finding that intestinal growth lags behind body weight growth suggests that intestinal capacity may need special attention in modern fast-growing chicken breeds. Confidence level: Moderate—this is solid descriptive research, but intervention studies are needed to confirm whether modifying feeding strategies based on this information actually improves chicken health or growth.

This research is primarily relevant to poultry farmers, hatchery managers, and animal nutritionists who work with broiler chickens. It may also interest veterinarians who treat poultry and researchers studying animal nutrition and development. The findings are less directly applicable to people raising backyard chickens or other poultry species, though some principles may transfer. This research is not directly relevant to human nutrition, though the basic principles of intestinal development may have some parallels in other species.

The changes described in this study occur over four weeks in young chickens. Farmers implementing feeding changes based on this research would need to evaluate results over similar timeframes. Benefits from optimized feeding strategies (if they are developed based on this research) would likely become apparent within the first month of a chicken’s life, which is when most of the intestinal development occurs. Long-term effects on overall chicken health and growth would need to be evaluated over the entire production cycle (typically 6-7 weeks for broilers).

Want to Apply This Research?

  • For poultry farmers using a farm management app: Track daily feed intake and growth rate (body weight) for each flock, noting the age of the birds. Once feeding strategies based on intestinal development research are developed, measure and record feed conversion efficiency (pounds of feed needed per pound of body weight gained) at weekly intervals during the first four weeks. This metric directly reflects how well the intestines are absorbing nutrients.
  • Implement age-specific feeding programs that account for the different rates of intestinal development in the first four weeks. For example, provide feed formulations optimized for the first week when intestinal development is most rapid, then adjust formulations as development slows. Monitor flock health indicators (mortality, disease incidence, feed intake) weekly to ensure feeding changes support overall bird health.
  • Establish a baseline of current performance metrics (feed conversion ratio, growth rate, intestinal health indicators if available) for your current feeding program. After implementing any changes based on this research, track the same metrics weekly for at least one complete production cycle. Compare results to your baseline and to industry standards. Consider working with a poultry nutritionist to interpret results and make ongoing adjustments. Document environmental conditions (temperature, humidity, ventilation) as these factors also affect intestinal development and nutrient absorption.

This research describes normal intestinal development in broiler chickens and does not constitute medical or veterinary advice. The findings are based on observations in a controlled research setting and may not apply to all farming conditions or chicken breeds. Farmers should consult with licensed veterinarians and poultry nutritionists before making changes to feeding programs or management practices. This study does not evaluate the safety or efficacy of any specific feed additives, supplements, or feeding strategies. Any decisions about poultry management should be based on consultation with qualified professionals familiar with your specific operation and local regulations.