Campylobacter and Salmonella populations associated with chickens raised on acidified litter

Abstract

Two commercially available acidifying litter treatments, aluminum sulfate (alum) and sodium bisulfate, were tested to determine their effects on Campylobacter and Salmonella colonization frequencies and populations associated with broilers raised on treated pine litter. To produce contaminated litter, broiler chicks were inoculated with two bacterial cocktails (multistrain mixtures of campylobacters and salmonellae) and were allowed to shed on the litter for about 6 wk. Upon bird removal, litter in duplicate pens was immediately treated with two levels of aluminum sulfate [3.63 or 7.26 kg/4.6 m2 (8 or 16 lb/50 ft2)] or sodium bisulfate 1.13 or 1.81 kg/4.6 m2 (2.5 or 4 lb/50 ft2)]; untreated pens served as controls. Immediately after treatment, day-of-hatch chicks were released in the pens. Frequency and populations of Campylobacter and Salmonella associated with ceca and whole carcass rinse (WCR) samples were determined for each duplicate pen at Weeks 1, 4, and 6. Both levels of the aluminum sulfate and sodium bisulfate litter treatments tested significantly (P < 0.05) reduced Campylobacter colonization frequency and populations in the ceca. Significantly, no Campylobacter was recovered from WCR samples associated with high level aluminum sulfate-treated pens at any time; although control pens were 95, 78, and 38% positive at Weeks 1, 4, and 6, respectively. Salmonella colonization frequency and populations in the ceca were not significantly decreased by any of the treatments investigated. Although effective pathogen control will most likely require a combination of interventions, acidifying treatment of litter in poultry production may serve as a means to help control Campylobacter and to reduce horizontal transmission of pathogens in broiler flocks.