Editor's note: The following is from a presentation by Laura Greiner, PhD, Department of Animal Science, Iowa State University, during the 2024 James D. McKean Swine Disease Conference.

Escherichia coli (E. coli) is a common pathogen in young pigs. Over the years, the use of vaccinations and natural planned exposure methods have been employed in both the nursery and sow facilities to control potential outbreaks. In the last few years, the swine industry has seen an increase in enterotoxigenic Escherichia coli (ETEC) outbreaks and organism virulence. Furthermore, the timing of the outbreak has changed from the early nursery phases to mid- and late- nursery phases.

Clinical symptoms will start between the second- and third-week post-weaning with watery diarrhea that can extend over the period of multiple days. Mortality rates can increase from 2% up to over 20% with further complications of increased morbidity and reduced growth rates.

Nutritional interventions can be utilized to minimize ETEC infections. It is important to utilize these techniques with the guidance of a nutritionist. The goal when mitigating a potential infection is to minimize inflammation while preventing ETEC attachment through the change of intestinal viscosity, pH, microorganism competition, or direct antimicrobial activity.

Additional dietary phases: Switching from 3 to 4 nursery phases has been shown to reduce ETEC attachment. This is in part due to allowing for the complex diets to continue longer and reduce non-digestible crude protein.

Low crude protein diets: Reducing crude protein and supporting the amino acid requirements through feed grade amino acids has been accepted as a way to reduce fermentable protein from reaching the large intestine. Additional work has shown that feeding low crude protein diets improves goblet cell presence and reduced sodium-coupled glucose transporters.

Mineral inclusions (Zn and Cu): Feeding pharmacological levels of zinc and copper have long been used in nursery programs in the United States to control ETEC as these two minerals are involved in reducing pathogen adhesion and pathogen death. Due to the delay in ETEC activity to later nursery phases, nutritionists have fed pharmacological levels longer. However, it should be noted that feeding mineral levels that are too high or extending these levels for too long can result in lameness.

Fiber: The use of rolled oats has been shown to reduce ETEC shedding. Focusing on insoluble fiber inhibits proliferation and adhesion of ETEC in the intestine. Careful inclusion of fiber can be beneficial before and during phases when ETEC can be an issue.

Pre- pro- and postbiotics: Prebiotics, such as manno-oligosaccharides, can be fed to stimulate the growth of beneficial intestinal bacteria. Probiotics are live organisms that are added to the diet to increase the population of the fed organisms within the gut. Commonly fed organisms include Lactobacillus and Bifidobacterium. Postbiotics such as yeast and Lactobacillus have been shown to have a positive impact by regulating the immune system

Other additives: Other products that can also stop ETEC include clays, phytogens, antibiotics, and medium-chained fatty acids. In addition, products such as spray-dried plasma, organic acids, and egg antibodies have long been shown to reduce ETEC shedding.