A comparison of culturing drag swabs and litter for identification of infections with Salmonella spp. in commercial chicken flocks.

The use of a culture of a 5-g litter sample and the use of drag swab to detect Salmonellae infections in broiler and parent breeding flocks were compared to determine sensitivity of the techniques. The methods were equally sensitive in 32 breeding houses. Both identified the same sheds as being contaminated, and the identical serotypes were recovered. In broiler flocks, however, contamination of 7 of 13 sheds was detected with drag swabs, whereas only 5 were detected by litter culture. In a repeat experiment in broiler sheds, 3 sheds were detected as positive by the culture of litter, 9 by drag-swab culture. All sheds found positive by culture of cacae at processing had been identified by drag-swab culture during the life of the broilers. It was concluded that drag-swab culture was a reliable and cheap method of monitoring large numbers of chicken flocks for infections with Salmonella spp.