The investigation of Salmonella contamination model in broiler breeder farms in Taiwan

Salmonella is one of the important causes of human food disease, and people were often infected through ingestion of contaminated poultry and poultry products. The purpose of this study is to identify and clarify the pollution patterns of broiler breeder farms in Taiwan, and help the government carry out the monitor plan and develop the Salmonella control plan of broiler breeder farms. In this study, 14 broiler breeder farms in Taiwan were investigated by longitudinal observation since the first days of the 1-day-old chicken. The total numbers of samples were 2132, including 1-day-old chicken (there are only 11 farms sent samples of 1-day-old chichken), shoe covers stained with litter and feces, feed, water, suspended eggs and hatched chicken, and was divided into 1080 test samples according to the different types of samples. The total isolation rate was 8.3% (90/1080); the isolation rate of 1-day-old chicken was 24.6% (15/61); the isolation rate of shoe covers stained with litter and feces was 13.1% (52/398); the isolation rate of feed was 5.5% (16/292); the isolation rate of water was 0% (0/133); the isolation rate of suspended eggs and hatched chicken was 3.6% (7/196). In the 14 breeder farms, Salmonella were isolated from 12 farms, and the farm positive rate was 85.7%(12/14). In this study, S. Albany, S. Duesseldorf, and S. Schwarzengrund were the most frequently isolated serotypes and we used pulsed field gel electrophoresis to identify the genetic relationships of Salmonella isolates. These results showed that samples of 1-day-old chicken are important sources of Salmonella infection and though feed can be contaminated by Salmonella, the risk of Salmonella infection of chicken from feed is not very high. The Salmonella of the same genotype can persistently transmit in the broiler breeder farm, and may transmit to the child commercial broiler through vertical transmittion. Therefore, it is an important key to buy Salmonella free broiler breeder chicks. In this study we also found that the relationship of Salmonella infection between the numbers of broiler breeder and the raising facilities of broiler breeder farms is not close.