The effect of dietary chicken egg-yolk antibodies on the clinical response in weaned pigs challenged with a K88+ Escherichia coli isolate

Abstract

Objectives: To determine if supplementing the diet of weaned pigs with a specific chicken egg-yolk-antibody product would protect against experimentally induced colibacillosis. Methods: Four treatment groups of 12 newly weaned pigs (approximately 22 days old) were fed either a control diet (Groups 1 and 2) or the same diet containing chicken egg-yolk antibodies (IgY) at inclusion rates of 0.32% (Group 3) and 3.2% (Group 4). Pigs in Groups 2, 3, and 4 were challenged with 5 mL of a suspension containing 1011 colony forming units per mL of a K88+ isolate of Escherichia coli. Results: Pigs in Group 1 (unchallenged controls) did not develop diarrhea. In the three groups challenged with E coli, pigs developed watery diarrhea and dehydration. Prevalence and severity of clinical signs were similar in all three groups. No appreciable levels of IgY were detected either in treated or control pigs by ELISA testing of small intestine content. Discussion: The E coli challenge was successful in creating a clinical response similar to field cases. The presence of chicken egg-yolk antibodies in the ration did not appear to be effective in preventing the disease. It is possible that IgY activity is greatly reduced by gastric acid and pepsin, and therefore, even at high inclusion rates, egg-yolk antibodies may not be efficacious in pigs as old as 3 to 4 weeks of age. Implications: Supplementation of chicken egg-yolk-antibody products may not be effective in controlling postweaning E coli diarrhea.