Effect of the housing system on shedding and colonization of gut and internal organs of laying hens with Salmonella Enteritidis

As a result of welfare considerations, conventional cage systems will be banned in the European Union from 2012 onward. Currently, there is limited information on the level of contamination with zoonotic pathogens related to the laying hen housing system. Therefore, 2 studies were designed to investigate the effect of the housing system on colonization of layers with Salmonella. In both studies, layers were housed in 3 different housing systems: a conventional cage system, a furnished cage, and an aviary. At 18 wk of age, all birds were orally inoculated with Salmonella Enteritidis. Shedding and colonization were measured at regular time points. The results did not show an increased risk for alternative housing systems compared with the conventional battery cage system. In contrast, in one study, a faster decline in shedding was noted for layers housed in the alternative cage systems in comparison with the conventional cage system. This study does not give indications that housing layers in alternative systems will yield a risk for increased Salmonella contamination.