Strategies can control necrotic enteritis, coccidiosis (Poultry Specialist)
(Editor’s note: Jennifer Timmons is an assistant professor for University of Maryland Eastern Shore.)
Necrotic enteritis is a bacterial infection caused by Clostridium perfringens.
It has been reported that the economic impact of necrotic enteritis worldwide is between $5-6 billion.
Low levels of Clostridium perfringens reside naturally in the bird’s intestines.
Necrotic enteritis results when an imbalance of the intestinal ecosystem occurs as a result in a change in pH or an increased viscosity of the intestinal digesta, for example.
One of the most common predisposing factors to necrotic enteritis is damage of the intestines from coccidial infection.
It is estimated that the combined economic loss of necrotic enteritis and coccidiosis is about $10 billion.
The poultry industry controls coccidiosis with the use of anti-coccidial drugs in the feed or with vaccinations.
In addition to these strategies, there are a number of nutritional alternatives that are available and being investigated.
Functional oils are oils that have a benefit beyond nutritional value.
Two of these oils are castor oil and cashew nut shell oil.
A study that fed a combination of these two oils to broiler chickens challenged with coccidiosis reported that livability and gut score lesions were improved compared to the livability and gut score lesions of birds fed a non-supplemented diet.
In addition to functional oils, tannins, which are a large group of chemical compounds in plants have also shown to be beneficial to control coccidiosis.
Tannins have known anti-parasitic and antibacterial activities in ruminant animals.
Algae based products have also been evaluated for benefits against coccidiosis infection in broilers.
Studies suggested that algae may not directly decrease the growth of coccidia species, but may be able to increase the intestinal response to coccidia which therefore improves the bird’s ability to defend itself from coccidia invasion.
Feed management can also be used as a means to control the incidence of necrotic enteritis.
One study showed that feed restriction of broiler chicks for 12 hours from 16-19 days of age limited the severity of necrotic enteritis and reduced the Clostridium perfringens population in the cecum.
The authors reported that the benefit of feed restriction against necrotic enteritis was most likely due to the lower pH and viscosity of digesta in the intestines.
Although feed restriction of broiler chickens showed a benefit to controlling necrotic enteritis in this study, this may not be practical for commercial broiler production.
Diets using ingredients such as wheat and barley that are high in non-starch polysaccharides could increase the viscosity of the digesta, and can effect gut microbial activity.
This can increase fermentation and shift to an environment in the gut which favors the growth of Clostridium perfringens.
Mycotoxins can also negatively impact the integrity of the small intestines and are associated with suppression of the immune system which can also increase the severity of coccidiosis and necrotic enteritis.
Necrotic enteritis and coccidiosis are gut health issues and depend on many factors to cause the disease.
Factors such as coccidiosis that alter the integrity of the intestines can lead to the growth of Clostridium perfringens which can cause necrotic enteritis.
The poultry industry continues to strive to look for strategies to control these very costly diseases.
Just like the many factors that cause these diseases, there are multiple factors that are implemented to reduce their incidence as well.