Necrotic enteritis is making a comeback

Reduced use of antibiotics and changing poultry diets are contributing to a rise in cases of the disease that can cause heightened mortality and lower feed conversion.

As more broiler flocks become antibiotic free (ABF), necrotic enteritis is making a comeback. A leading poultry scientist says controlling the potentially fatal disease requires closer attention to gut health.

During the Poultry Science Association’s annual meeting in New Orleans in July 2016, Dr. Charles Hofacre, a professor and director of clinical services at the University of Georgia’s College of Veterinary Medicine Poultry Diagnostic & Research Center, spoke on the resurgence of the disease caused by the bacteria Clostridium perfringens and what steps should be taken to limit the disease’s spread.

Hofacre said when he was in school, the disease was only seen in textbooks and rarely in the field. Now, with the use of antibiotics limited by voluntary and regulatory decisions and poultry diets and feeding schedules changing, the disease is making a major comeback.

The disease can affect all commercial avian species, Hofacre said, and the bacteria naturally exists in soil and likely in every poultry house. Along with removal of growth-promoting antibiotics that historically kept the disease in check, the welfare-driven shift toward feeding birds less often or consumer-driven shift toward feeding birds vegetarian or other specialty diets may be making their intestines more susceptible to necrotic enteritis.

On a clinical level, the disease can cause 50 percent mortality or more in broilers. The most costly infection is subclinical, he said, when the birds don’t die but instead don’t fully utilize the nutrients of their diet and pass partially digested feed. Feed is the most expensive part of poultry farming so, essentially, Hofacre said, those birds are passing money.

Hofacre said the disease could be severe in the U.S. and research suggests as many as 50 percent of poultry houses are going have clinical and subclinical necrotic enteritis. Farmers with worse hygiene are going to be more likely to see the disease.

To prevent the disease in broiler flocks, Hofacre offered the following suggestions:

• Focus on the gut flora. With the steady removal of antibiotics in global poultry production, greater attention is being given to how the gut flora can influence the health of birds. Historically, antibiotics and ionophores have helped maintain animal health, but now farmers must turn to probiotics, plant-based compounds and other additives to stimulate a healthy gut.

Farmers cannot eliminate Clostridium, so they need to look into how a healthy gut flora can limit the negative impact of necrotic enteritis. Unfortunately, no single product is going to work as well as antibiotics, Hofacre said, so combinations of different additives must be tried to see what works best at stimulating helpful gut flora.

• Make the grower a part of the team. Hofacre said in the ABF world, the integrator must consider the contract grower as part of the team. This means educating them on how to create better sanitary conditions to limit the potential for necrotic enteritis and empowering them to take responsibility for preventing the disease.