Two similar trials were conducted to evaluate broiler carcasses at retail for incidence, number, and serotypes of salmonellae. Twelve frozen carcasses were purchased from each of three retail outlets on two sampling days. Two of the brands purchased were produced and processed conventionally, but the third brand was produced and processed under organic conditions. The frozen carcasses were tempered to 4.4 C prior to microbiological sampling. All carcasses were sampled using a mechanical shaker and 100 mL of sterile water. Recovered rinse fluid was evaluated for levels of salmonellae using a three-tube most probable number technique. All recovered Salmonella isolates were serotyped using the Kauffmann-White scheme. Incidence rates across the three brands ranged from 17 to 50%, with most probable number of salmonellae per 100 mL of recovered rinse fluid ranging from 5 to 34 organisms. Serotypes recovered include Salmonella typhimurium, Salmonella paratyphi, and Salmonella arizonae.

Two similar trials were conducted to evaluate the accuracy of the whole carcass rinse technique in combination with a most probable number (MPN) procedure for estimating the number of salmonellae on postchill broilers. Birds were reared in litter-floored pens and inoculated with Salmonella typhimurium (10(8) cfu/mL) on Days 2, 7, and 14. In each of the two trials six carcasses were consecutively rinsed four times. Each carcass was rinsed with 100 mL of sterile water in sterile plastic bags using an automated shaking device. Salmonellae were enumerated using a three-tube MPN procedure in selenite cystine broth. There were no statistical differences in log10 MPN salmonellae per milliliter of recovered rinse fluid due to trial or consecutive rinse. In several cases salmonellae were not recovered in the initial rinse but were recovered from consecutive rinses of the same carcass. A large amount of variation in MPN levels of salmonellae among individual carcasses occurred within each consecutive rinse. The data suggested that only a percentage of the total salmonellae present on a postchill carcass were recovered with each consecutive rinse, and the organisms were firmly attached prior to processing.

Two trials were conducted to compare the standard culture procedure and the Report Salmonella Visual Immunoassay for detection of salmonellae in rinse fluid recovered from raw poultry carcasses. Both assays were evaluated with and without preenrichment in lactose broth prior to enrichment in selenite cystine broth. Live birds were inoculated via the drinking water prior to processing to ensure a high degree of carcass contamination. Prechill carcasses were sampled using 200 mL of sterile water. Results indicated that lactose preenrichment was not necessary for salmonellae evaluation using standard culture procedures. However, the Report assay produced fewer false-negative results if lactose preenrichment was utilized.

Two similar trials were conducted to evaluate the effects of bird density on Salmonella contamination of processed broilers. Commercial strain broiler chicks were reared in floor pens on new litter at densities of 557, 619, 697, 796, 929, and 1,115 cm2 per bird. Twenty percent of the chicks in each density were gavaged directly into the crop with .5 mL of 10(8) nalidixic-acid-resistant (NAR) Salmonella typhimurium on Day 2. Twenty percent of the uninoculated birds in each density category were processed at 42 days. Prechill carcasses were evaluated for NAR Salmonella incidence using the whole carcass rinse technique and a mechanical shaking device. The resulting NAR Salmonella contamination rates (from lowest to highest bird densities) were as follows, 55, 4.2, 35.7, 34.3, 88.9, and 20% in Trial 1; and 30, 20.8, 28.6, 50, 58.3, and 30% in Trial 2. A random sample of the prechill carcasses of gavaged birds indicated a contamination rate of 13.8% in Trial 1 and 61.1% in Trial 2. The NAR Salmonella contamination rates of the prechill carcasses did not appear to be affected by the bird densities evaluated in these trials. Feed intake and body weight at 42 days were adversely affected by the highest bird density, but feed utilization was not affected.

A study was conducted to determine the effects of propylene glycol (PG) and lactic acid (LA) alone, or in combination, on levels of salmonellae on broiler carcasses. Chicks were inoculated with salmonellae via the drinking water on days 2 , 7, 14, and 21. At 49 days, birds were processed and the carcasses were subjected to chemical treatment in the chill water. Two treatments were effective in completely eliminating salmonellae from the carcass (0.25% LA + 20% PG or 0.50% LA + 20% PG). However, both levels of LA resulted in discoloration of the skin, and all levels of PG that were evaluated (5, 10, or 20%) produced carcasses that exhibited a sickeningly sweet odor. Color and odor problems did not diminish with time.