Passive protective effect of egg-yolk antibodies against enterotoxigenic Escherichia coli K88+ infection in neonatal and early-weaned piglets

The protective effects of egg-yolk antibodies obtained from hens immunized with fimbrial antigens from a local strain (Escherichia coli K88+ MB, Manit oba, Canada) of K88+ piliated enterotoxigenic E. coli (ETEC) were evaluated in 3- and 21-day-old piglets in which ETEC diarrhea was induced and also i n early-weaned piglets in a commercial farm. The results demonstrated that the E. coli K88+ MB-induced diarrhea in 3-day-old piglets was cured 24 h af ter treating with egg-yolk antibodies while those treated with egg-yolk pow der from conventional hens continued to have diarrhea and 62.5% of them die d of severe diarrhea. For 21-day-old weaned piglets, those fed egg-yolk ant ibodies had transient diarrhea, positive body weight gains and 100% surviva l during the period of the experiment, whereas control piglets that were tr eated with placebo had severe diarrhea and dehydration and some died within 48 h after infection. In the field trial, the incidence and severity of di arrhea of 14-18-day-old weaned piglets fed egg-yolk antibodies were much lo wer than in those fed a commercial diet containing an antibiotic. These res ults indicate that the neonatal and early weaned piglets that received the egg-yolk antibodies were protected against ETEC infection. (C) 1999 Federat ion of European Microbiological Societies. Published by Elsevier Science B. V. All rights reserved.