Application of High Energy and Protein Diets in Combination with a Live Avirulent Escherichia coli F4 Vaccine Against Post-Weaning Diarrhea

Introduction: Post-weaning diarrhea (PWD) in pigs is a worldwide economically important disease, which is frequently controlled using antibiotics. However, emergence of antimicrobial resistance in Escherichia coli strains urges the need for alternative control measures, such as adapted feeding strategies, pre- and probiotics, organic acids, MCFAs or immunization. Methods: Different alternative control strategies such as active immunization of piglets against PWD with an E. coli F4 vaccine (Coliprotec® F4; Elanco) combined with high energy and protein diets, addition of nutraceuticals (medium chain fatty acids (MCFAs), organic acids and additional fibers) or supplementation of ZnO were evaluated for their efficacy against PWD due to F4 enterotoxigenic E. coli (F4-ETEC) under field conditions. Results: ZnO-supplemented piglets had a lower overall end weight and lower average daily weight gain, as compared to E. coli vaccinated piglets. The E. coli vaccinated group with normal energy and protein diet had the lowest clinical scores, whereas piglets fed a ZnO-supplemented diet had intermediate fecal clinical scores. All E. coli vaccinated groups had a low number of antibiotic treatments. In the nutraceutical group, clinical scores were much higher, indicating more severe clinical diarrhea, which needed additional antibiotic intervention. Conclusions: The present study demonstrated the efficacy of an oral live non-pathogenic E. coli F4 vaccine for active immunization of piglets against PWD due to F4-ETEC under field conditions. Different feeding strategies had no significant effect on the clinical outcome and performance parameters of E. coli vaccinated piglets.