Risk Factors for Necrotic Enteritis in Organic Broilers: A Longitudinal Surveillance Study

Commodities

• Animals: poultry
• Animal Products: meat

Practices

• Animal Production: animal protection and health, preventive practices
• Production Systems: organic agriculture

Necrotic enteritis remains a persistent and costly challenge in organic broiler production, where limited treatment options make early detection and prevention critical. The disease is closely linked to disruptions in gut health, specifically involving Clostridium perfringens and Eimeria spp. However, producers currently have limited tools to monitor prevalence, persistence, and interactions between microbes. As a result, it is difficult to recognize when disease risk is increasing and to implement timely, organic-compliant interventions.

This project aims to improve the management of necrotic enteritis in organic broilers by (1) characterizing changes in relative abundance of Clostridium spp. and Eimeria spp. over the course of growout and related to clinical signs, and (2) evaluating a practical, organic-compliant intervention for flocks that develop necrotic enteritis. The goal is to provide producers with actionable data into early risk detection and feasible response options within the certified organic guidelines.

To meet these objectives, Barnwell Bio will conduct a two-part field study across two organic broiler production locations with historical outbreaks of necrotic enteritis, following five flocks per location over one year. Each flock will have an environmental sample collected weekly from placement until slaughter to quantify pathogen abundance. These data will be paired with flock-level observations, including morbidity and mortality, litter condition, environmental temperature and humidity, management practices, and clinical signs consistent with necrotic enteritis. Flocks that develop disease will enter a second phase in which an organic-compliant intervention is implemented and evaluated based on changes in flock health and performance indicators.

Results will be shared through a combination of in-person meetings and outreach efforts designed to support producer education and adoption of any identified control strategies. A producer-focused meeting will be held to present findings, discuss practical implications, and gather feedback. To extend impact, we will develop clear, producer-friendly materials, including a summary report and decision support guide outlining early risk indicators and management considerations for necrotic enteritis. The outreach material will focus on organic broiler production, but any relevant information will also be conveyed to conventional broiler and layer producers. Findings will also be shared through webinar and digital formats, as well as through extension and industry networks, to reach a broader audience of poultry producers. These efforts will ensure that results are translated into practical, actionable strategies that producers can use to improve flock health and management.

The overall goal of this project is to improve prevention and management of necrotic enteritis (NE) in organic broiler production by generating practical, field-based insights on pathogen dynamics, virulence factors, and organic-compliant response strategies.

Objective 1: Quantify longitudinal changes and dynamics in the relative abundance of Clostridium perfringens and Eimeria spp. across 10 organic commercial broiler flocks in two locations throughout the grow-out period using routine environmental sampling.

Objective 2: Characterize the distribution of key Clostridium perfringens toxin genes in selected samples to identify virulence profiles associated with increased risk of necrotic enteritis.

Objective 3: Assess the relationship between pathogen abundance and clinical indicators of necrotic enteritis by integrating flock-level data (mortality, litter conditions, and enteric clinical signs) to identify periods of elevated gut health risk.

Objective 4: Assess the effectiveness of an organic-compliant intervention for necrotic enteritis under field conditions and develop practical, producer-focused recommendations for early detection and management in organic broiler systems.

Objective 5: Translate project findings into practical, producer-focused outreach and education by delivering a producer meeting, decision-support tools, and accessible educational materials that support adoption of early risk detection and organic-compliant management strategies for necrotic enteritis.