A Survey of Salmonella Contamination in Modern Broiler Production

A survey of contamination with Salmonella was done in the breeder/multiplier and broiler houses, feed mills, hatcheries, and processing plants of two integrated broiler firms. Samples of insects and mice were also collected at each location. Sixty percent (60%) of the meat and bone meal samples collected at feed mills were contaminated. Salmonella was isolated from 35% of the mash feed samples tested. The pelleting process reduced Salmonella isolation rates by 82.0%. Data collected from breeder/multiplier houses suggested that feed was the ultimate source of Salmonella contamination in that environment. Salmonella was found in 9.4% of the yolk sac samples collected from day-old chicks in hatcheries. Fecal dropping samples collected in broiler houses about one week prior to slaughter were contaminated at a rate of 5.2%. Salmonella was found in 33% of the samples collected from live haul trucks and 21.4% of the whole processed broiler carcasses sampled at processing plants. Salmonella typhimurium was the serotype most commonly isolated. The gastrointestinal tract of one of 19 mice sampled was contaminated with Salmonella. Data suggest that insects were primarily mechanical carriers. Results suggest Salmonella contamination in the U.S. broiler production and processing system has changed little since 1969. The data also underline the contention that effective Salmonella control efforts must be comprehensive.