Effect of cold fog disinfection on Escherichia coli affecting commercial egg layer flocks

On a field level among poultry flocks a study was conducted to estimate the efficacy of the most common disinfectants against E. coli (APEC isolates) was determined. The selected disinfectants were; Formalin, Phenol, QAC, Halamid, Virkon" S and Micro Sept M against E. coli isolates of commercial egg- layer flocks in Egyptian farms. The recovered results showed that: (1) the incidence of E. coli in the observed commercial egg-layer flocks; the isolation of E. coli (APEC of rfbO157 gene ) from 4 commercial egg-layer flocks (26.7 %) out of 15 flocks, the mortalities rates at the end of 78 weeks of age was 20% and also, the current egg-production, average egg weight, hen housed day, hen housed egg and percent peak of egg-production were: 69.2%,58.3 gm, 70%,326,78% and 69%,respectivel. (2) Formalin, Micro Sept M and Virkon'S treatment demonstrated a significant reduction in E. coli populations especially by cold fogging method.