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Autogenous vaccine against Escherichia coli and Gallibacterium anatis reduces losses and improves production on layer farms

Gallibacterium anatis and avian pathogenic E.coli (APEC) is one of the most frequent pathogen combination found in layer flocks today, causing serious problems with increased mortality and drop in egg production combined with high multidrug resistance. If other pathogens are involved, like MS, MG, IB, ART etc, loses could be significantly higher. The purpose of this study was to determine influence of bivalent autogenous vaccines on flock performance, made on farmers request from local G.anatis and APEC strains. Farms were visited or carcass/swab samples were sent for isolation of APEC and G.anatis strains, which were confirmed by MALDI- TOF spectrometry and selected for vaccine production. Antigen solution is dispersed in oil adjuvant and given in 0, 4 ml with 10^8 CFU per dose twice per pullet at 9 and 18 weeks of age. Flocks were also monitored for other diseases by serology, together with production parameters and weekly mortality and compared to previous flocks. Farms included in this study showed high incidence of colibacillosis with high percentage of fibrinous poliserositis and high percentage of APEC strains isolated from bone marrow and liver, but also G. anatis strains were isolated from liver, oviduct or egg follicles. Both species were also multidrug resistant. Nonvaccinated flocks reached peak, but production was later irregular with elevated mortality, on average around 0, 7% per week, sometimes reaching around 2, 6% per week. Those flocks were MS, MG and ART negative, and IB vaccination program was adjusted to cover broad spectrum of strains. Vaccinated flocks reached peak without later fluctuations, but mortality was 0, 078% per week on average, with max 0, 10% per week. Results showed significant influence of autogenous vaccine on flock performance, confirming that combination of APEC and G. anatis strains were the main causative agents of problems in previous flocks. Also, due to the high multidrug resistance of isolated strains and the fact that egg production is not compatible with drug application, autogenous vaccines seem to be the method of choice for successful egg production.

APEC, Autogenous vaccines, Egg production, Gallibacterium anatis, Layers

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