The relationship between feed quality and gut health in livestock operates through multiple interconnected pathways. Physical feed characteristics, microbial load and processing parameters all influence the gastrointestinal environment, affecting everything from nutrient absorption to immune function.
Technical Director EMEA
Anitox
The livestock industry continues to face mounting pressure to optimize animal performance while maintaining health and welfare standards. Among the various factors influencing livestock productivity, feed quality has emerged as a fundamental determinant of gut health, with far-reaching implications for animal performance, disease resistance and economic viability.
UNDERSTANDING THE FEED QUALITY-GUT HEALTH CONNECTION
The relationship between feed quality and gut health operates through multiple interconnected pathways. Physical feed characteristics, microbial load and processing parameters all influence the gastrointestinal environment, affecting everything from nutrient absorption to immune function. In poultry, this relationship has been extensively studied due to the species’ economic importance and the relative ease of conducting controlled experiments.
Gut health encompasses several measurable parameters, including intestinal development and morphology (villus height and crypt depth ratios), lesion scores, microbiome composition and functional indicators such as nutrient digestibility. These parameters serve as biomarkers for overall intestinal integrity and function, providing researchers and producers with quantifiable metrics to assess feed quality impacts.
PHYSICAL FEED STRUCTURE AND INTESTINAL PERFORMANCE
One of the most significant discoveries in recent poultry research relates to pellet durability and its impact on bird performance. The Pellet Durability Index (PDI) and fines percentage have emerged as critical quality metrics that directly influence feed conversion ratios (FCR) and average daily gain (ADG) in broilers.
Research demonstrates that pellets with high durability consistently outperform lower-quality alternatives and mash feeds. In controlled studies, high-quality pellets produced FCR values of 1.85-1.88, compared to 2.02 for mash diets – representing improvements of 8-9% in feed efficiency (Chewning, Stark, & Brake, 2012). This improvement translates to substantial economic benefits when scaled across commercial operations.
The mechanism behind these improvements appears to be multifaceted. High-quality pellets reduce feed wastage, improve nutrient intake consistency and may enhance the physical stimulation of the digestive tract. The reduced fines content (typically 6-27% in high-quality pellets versus 40-50% in poor-quality feed) ensures that birds consume a more uniform nutrient profile, reducing the selective feeding behavior that can lead to nutritional imbalances.
Weight gain responses to improved pellet quality show similar patterns, with studies reporting gains of 50-120g in male broilers and 71-90g in females when comparing high-quality pellets to alternatives (Pope, Brake, & Fahrenholz, 2018). These improvements were statistically significant (p < 0.01 for males, p < 0.05 for females), indicating robust biological responses to physical feed quality improvements.
MICROBIAL LOAD AND INTESTINAL HEALTH
The microbial quality of feed represents another critical factor influencing gut health, though research in this area reveals significant gaps in current understanding. Studies examining the relationship between feed microbial load and intestinal health parameters show promising but incomplete results.
Research investigating overall microbial load control in feed demonstrated substantial improvements in broiler performance during disease challenges. In battery trials, controlling microbial load resulted in 14% improvement in feed conversion, 16.5% increases in body weight gain and a remarkable 72.5% reduction in necrotic enteritis-associated mortality (Richardson, Hofacre, Mathis, Lumpkins & Phillips, 2017). These results suggest that feed microbial quality plays a crucial role in disease resistance and overall gut health.
However, current research limitations prevent definitive conclusions about specific microbial parameters. Studies often report “overall microbial load” without quantifying specific organisms such as Enterobacteriaceae, Salmonella, or mold and yeast levels. This lack of specificity represents a significant knowledge gap that requires further investigation to establish clear guidelines for feed microbial quality standards.
ECONOMIC AND PRODUCTION IMPLICATIONS
The economic implications of these findings are substantial. Feed conversion improvements of 8-14% translate directly to reduced feed costs per unit of meat produced. Given that feed typically represents 60-70% of total production costs in poultry operations, even modest improvements in FCR can significantly impact profitability.
Additionally, the mortality reductions associated with improved microbial quality (up to 72.5% reduction in necrotic enteritis-related deaths) represent both economic and welfare benefits. Reduced mortality improves overall flock performance while decreasing the need for therapeutic interventions, supporting antibiotic-free production goals.
KNOWLEDGE GAPS AND FUTURE RESEARCH DIRECTIONS
Despite these promising findings, significant knowledge gaps remain in our understanding of feed quality-gut health relationships. Current research reveals two critical areas requiring further investigation:
First, the specific mechanisms by which pellet quality influences gut morphology and function remain poorly understood. While performance improvements are well-documented, the underlying physiological changes in intestinal structure and function require detailed investigation.
Second, research into specific microbial parameters and their individual contributions to gut health is urgently needed. The current focus on “overall microbial load” provides limited guidance for establishing targeted quality control measures.
PRACTICAL APPLICATIONS AND INDUSTRY RECOMMENDATIONS
Based on current research, several practical recommendations emerge for livestock producers:
1. Prioritize pellet quality metrics, targeting PDI values above 90% and minimizing fines content below 30% where possible.
2. Implement comprehensive microbial quality control programs for feed ingredients and finished feeds, even though specific targets remain to be established.
3. Consider housing system effects when evaluating feed quality investments, recognizing that benefits may vary across production environments.
4. Monitor gut health indicators alongside traditional performance metrics to better understand feed quality impacts.
Feed quality’s impact on gut health represents a critical frontier in animal production, with documented improvements in feed conversion, weight gain and disease resistance justifying continued investment. While significant knowledge gaps remain in microbial quality specifications and underlying mechanisms, the evidence is clear: physical structure and microbial quality matter as much as nutrient content for livestock performance and welfare.
Advancing this understanding requires collaboration between researchers, producers and technology partners committed to safer, more efficient food production. Anitox works alongside the global food industry to address these challenges through science-based approaches to feed hygiene and quality.
References
1. Chewning, C., Stark, C. & Brake, J. (2012). Effects of particle size and feed form on broiler performance
2. Pope, J. T., Brake, J. & Fahrenholz, A. (2018). Post‐pellet liquid application fat disproportionately coats fines and affects mixed‐sex broiler live performance from 16 to 42 d of age
3. Richardson, K., Hofacre, C., Mathis, G., Lumpkins, B. & Phillips, R. (2017). Impact of controlling bacteria in feed on broiler performance during a clostridial challenge. Avian Diseases
About Dr. Antonio Ricci
As the Technical Director (EMEA) at Anitox, Dr. Antonio Ricci oversees strategies to strengthen poultry health, biosecurity, and sustainable production. A veterinarian with more than a decade of experience, he has held roles in clinical practice and diagnostics with organizations including Slate Hall Veterinary Services, IDEXX and Poultry Health Services. Dr. Ricci holds a Veterinary Medicine degree and a Master’s in Veterinary Clinical Sciences from the Università degli Studi di Napoli Federico II. He is dedicated to advancing animal welfare and safe food systems.
