Effect of E. coli infection on immune response and growth in Ducks

The purpose of this study was to asses the effect of Escherichia coli infection, experimentally, by using different routes at various ages, on performance parameters and immune response in ducks.One hundred and seventy five (175) apparently healthy day-old-white Pekin ducks were deployed in this study and divided into five experimental designs according to the aim of this work.First experiment designed to study the pathogenicity of E.coli O78 by using different routes of infection at different ages and its effect on feed intake, body weight and feed conversion ratio of ducklings on weekly bases for 5 weeks.Intramuscular route was the most pathogenic with mortality rate from 20% to 80% according to age of infected bird, while oral route recorded no mortality at all ages.Feed IntakeIn the 5th week of age, all infected ducklings showed decrease in feed intake, with reduction percentage ranged from 8.4 to 21.3%, in comparison with the control group (775 gm), according to the route and the age of the bird at the time of infection. HoweSummaryBody WeightAll infected subgroups showed reduction in body weight and body gain. However, the reduction percentage in body weight was 24.9-37% in ducklings of subgroups 1a, 2a, 3a and 4a (infected intramuscularly) while it was lower in orally infected subgroups 1b, Feed Conversion RateAll infected ducklings showed higher value of feed conversion rate than that of non infected control ducklings. The increase parentage in intramuscular infected ducklings was 15-35% while showed it was 5-10% in oral infected ducklings.