Evaluation of Litter Treatments on Salmonella Recovery from Poultry Litter

Evaluations were conducted to determine the efficacy of two litter amendments in reducing or eliminating Salmonella recovery from kiln-dried pine shaving based broiler litter. The litter had been exposed to one and three flocks of birds for Trials 1 and 2, respectively. Litter was placed at a 2-in. depth in 1-ft 2 baking pans and autoclaved. In Trial 1, the pans were inoculated with 100 mL of 10 4 cfu/mL nalidixic acid-resistant Salmonella typhimurium (NAL-SAL). In Trial 2, all pans were inoculated with 50 mL of 10 5 cfu/mL. In Trial 1, a granulated sulfuric acid litter treatment was applied at 100 and 150 lb/1,000 ft 2 . In Trial 2, a sodium bisulfate amendment, or a granulated sulfuric acid litter treatment, was applied at 25, 50, 75, and 100 lb/1,000 ft 2 . Samples were collected 24 h postinoculation and then enumerated on XLT 4 agar containing nalidixic acid. In Trial 1, the NAL-SAL control recovery rate was 4.4 log 1 0 per sample with zero recovery for the two rates of litter treatment. Litter pH for the control samples was 6.47. Litter treatment decreased the pH to 1.95 and 1.53 for the 100 and 150 lb/1,000 ft 2 rates, respectively. In Trial 2, control levels of NAL-SAL were 2.77 logic per sample. NAL-SAL levels increased to levels greater than those observed for the control at the litter treatment rate of 25 lb/1,000 ft 2 for both treatments. A treatment level of 100 lb/1,000 ft 2 was required for both litter treatments to decrease NAL-SAL to levels significantly different from the control. In Trial 2, the treatment of 100 lb/1,000 ft 2 decreased litter pH to 2.67 and 3.47, respectively, for the granulated sulfuric acid and sodium bisulfate treatments.