Necrotic enteritis causes economic loss for poultry producers around the world due to bird mortality and production inefficiency. The increasing restrictions on antibiotic growth promoter use have complicated the issue of necrotic enteritis control for antibiotic-free (ABF) producers. However, management programs and mineral-based feed additives can provide natural control methods to reduce the incidence of necrotic enteritis in flocks.
What Is Necrotic Enteritis?
Necrotic enteritis is caused by Clostridium perfringens, a spore-forming anerobic bacteria found throughout the poultry house environment and the normal microbiota of the bird. Disease in birds occurs when there are predisposing conditions, such as diet changes, immune status or intestinal pathophysiology, that cause an overgrowth of C. perfringens. The exotoxins alpha-toxin and necrotic enteritis B-like toxin (NetB) are produced by C. perfringens and have a role in necrotic enteritis development.
Necrotic enteritis occurs due to a breakdown of the defensive intestinal barrier (epithelium and mucus layer). The damage to the intestinal wall impairs nutrient digestion and absorption and can allow toxins to enter the circulatory system. Coccidiosis, caused by Eimeria spp., can increase the incidence of necrotic enteritis as Eimeria also damage intestinal cells. Mycotoxicosis from feed contaminated with fungal toxins can also increase the negative effects of necrotic enteritis. High mortality is a characteristic of clinical necrotic enteritis, while decreased weight gain and reduced feed efficiency are associated with subclinical disease.
Management Programs to Control Necrotic Enteritis
With the global push toward ABF production, maintaining a healthy intestinal environment to reduce the risk of necrotic enteritis now requires effective management strategies. Reduced ventilation, increased litter moisture and poor husbandry can increase the incidence of necrotic enteritis. However, natural feed additives that strengthen and protect the intestinal environment can also help reduce the risk of necrotic enteritis.
Natural Mineral-Based Feed Additives
Along with management best practices, the natural mineral-based feed additives Calibrin®-Z, Varium®, and NeutraPath® (all available in select international markets) can help maintain a healthy intestinal environment and reduce the incidence of necrotic enteritis. Third-party research has shown these products improve the health and performance of necrotic enteritis-challenged broilers.
Calibrin-Z for Broad-Spectrum Biotoxin Defense
Single-ingredient Calibrin-Z protects the intestinal barrier against damage from a broad spectrum of pathogens and bacterial and fungal toxins, including C. perfringens and E. coli toxins and aflatoxin, fumonisin and zearalenone. During manufacture, mineral-based Calibrin-Z undergoes proprietary thermal processing that permits multiple binding mechanisms, including hydrophobic interactions, chelation, hydrogen bonding and electrostatic attraction. The result is enhanced pathogen and toxin adsorption without significant binding of important nutrients.
In a study published in the Journal of Applied Poultry Research, Calibrin-Z reduced the effects of necrotic enteritis challenge, including returning gain during days 10 to 24 to levels equal to non-challenged birds. When birds were challenged with necrotic enteritis plus dietary aflatoxin (1 mg/kg), it significantly increased the negative effects of necrotic enteritis. However, Calibrin-Z improved feed efficiency to levels equivalent to birds challenged with necrotic enteritis only. Virginiamycin was not able to do this, demonstrating the benefits of feeding Calibrin-Z, which can bind mycotoxins and bacterial pathogens and their toxins.
Varium Promotes Poultry Efficiency and Productivity
Varium meets the poultry industry’s need to reduce the use of in-feed antibiotic growth promoters while maintaining bird health and performance and providing added-value for producers. Varium’s patented formulation includes Amlan’s mineral technology, yeast and a functional amino acid that work synergistically to reduce pathogenic challenges, strengthen the intestinal barrier and prepare the immune system to naturally defend against disease. With its multiple modes of action, Varium can replace the need for multiple feed additives by providing the same benefits in one product, reducing feed costs and simplifying diet formulations.
Multiple broiler studies have proven that Varium can be as effective as antibiotics in maintaining performance during necrotic enteritis challenge. In a study where necrotic enteritis-challenged broilers were fed for 28 days, feed conversion ratio (FCR), weight gain and mortality were similar between Varium and the antibiotic growth promoter bacitracin methylene disalicylate (BMD; Figure 1). Similar results were observed when Varium was compared to virginiamycin in another necrotic enteritis challenge study (Figure 2). These results show the value Varium can add to ABF systems by protecting the intestinal environment and promoting bird efficiency.
Figure 1: Weight gain and feed conversion ratio (FCR) of broilers fed BMD, Varium or non-supplemented for 28 days and undergoing necrotic enteritis challenge.
Figure 2: Weight gain and feed conversion ratio (FCR) of broilers fed virginiamycin, Varium or non-supplemented for 28 days and undergoing necrotic enteritis challenge.
NeutraPath for Natural Pathogen Control
Another natural option for managing necrotic enteritis is NeutraPath — a proprietary and co-active blend of essential oils, fatty acids and Amlan’s mineral technology. The synergistic formula of NeutraPath is designed to have multiple modes of action, resulting in enhanced intestinal health, improved feed efficiency and reduced mortality in necrotic enteritis-challenged birds. In environments with high bacterial challenge, NeutraPath can reduce the intestinal load and colonization of pathogenic bacteria and help maintain broiler gut health and structural integrity.
NeutraPath has bacteriostatic and bactericidal properties that target cell function and cell wall integrity of pathogenic bacteria. It also neutralizes virulence factors, including the toxins produced by pathogenic bacteria and the quorum-sensing molecules used for pathogen communication.
The on-farm benefits of pathogen control by NeutraPath have been demonstrated in multiple broiler trials. For example, in a 28-day trial that challenged broilers with C. perfringens and Eimeria, NeutraPath reduced mortality and lesion scores to levels similar to birds administered BMD (Figure 3). Additionally, broilers in the NeutraPath group had greater weight gain and a better FCR for the overall 28-day period than necrotic-enteritis challenged control birds, and NeutraPath-fed birds did not differ statistically from BMD-treated broilers (Figure 4). This study shows the performance benefits achieved with NeutraPath by improving intestinal health and reducing the intestinal pathogen load.
Figure 3: NeutraPath reduced mortality and lesions scores by half compared to the necrotic enteritis-challenged control. abcMeans with different superscripts are significantly different (P < 0.05).
Figure 4: NeutraPath improved weight gain and feed efficiency compared to the necrotic enteritis-challenged control. abMeans with different superscripts are significantly different (P < 0.05).
An increasing number of poultry producers are moving toward the global objective of reduced in-feed use of antibiotics. Consequently, maintaining a healthy intestinal environment now relies more heavily on other management methods to reduce the risk of necrotic enteritis. With best practice management strategies and inclusion of feed additives that promote intestinal health and function, poultry flock health can be improved, thereby reducing the risk of disease and maximizing production efficiency. To learn more about necrotic enteritis and the natural mineral-based feed additives that can help manage it, contact your local Amlan representative.