Association of Campylobacter jejuni with laying hens and eggs

Abstract

Laying hens were individually caged at 20 weeks of age and tested for fecal excretion of Campylobacter jejuni (minimum level of detection was 100 CFU/g) during a 42-week period. Peak rates of C. jejuni isolation (~25% of hens positive) occurred at two different times, in October and in late April to early May. Communal raising conditions were likely responsible for the high percentage of positive hens in October. Before being segregated in late September, birds were allowed to consume fecal matter, litter, and communal drinking water, all likely sources of C. jejuni. The increased excretion rate in April may have been due to a climatic change. A small portion (8.1%) of the hens chronically excreted (positive >30% of the sampling times) the organism, wereas C. jejuni was not detected in 33% of the hens, even though birds were likely exposed to the organism before being segregated. No correlation could be made between rates of C. jejuni extraction and egg production. Of 226 eggs from hens fecally excreting C. jejuni, the organism was isolated fom two shell surfaces but no egg contents. Egg penetration studies revealed that the organism would not penetrate into the contents of the eggs but could be isolated occasionally from the inner shell and membranes of refrigerated eggs.