Submitted to: Applied Poultry Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 11, 1997
Publication Date: N/A
Interpretive Summary: Salmonella is one of the most important bacteria involved in food poisoning. Therefore, several studies were performed to help understand the spread of Salmonella from infected chicks to non-infected chicks. Day- old-chicks were given Salmonella and were allowed to interact with chicks that were not given the bacteria. The originally non-infected chicks were then examined to determine if they became infected because they were raised in the same pens as the Salmonella infected birds. The results from this study suggest as few as 5 chicks given as little as 100 Salmonella cells will result in over half of the 100 original noninfected birds becoming infected with Salmonella. Our conclusions are that the spread of Salmonella from infected chicks to non-infected chicks is dependent on the number of Salmonella given and not the number of chicks originally exposed. These results will help poultry producers understand the importance of reducing the number of Salmonella in the hatchery and eventually will reduce contamination of food products.
Technical Abstract: Broiler breeder flocks and hatcheries have been identified as reservoirs of salmonella and potential sources of Salmonella infection for highly susceptible day-old-chicks. Once Salmonella has colonized the gastrointestinal tract of the chick, the bacteria replicate and are shed into the environment to infect other chicks. The horizontal spread of Salmonella will continue to cycle throughout the broiler flock, ultimately serving as a potential reservoir for future flocks. The present studies were conducted to evaluate horizontal transmission of Salmonella typhimurium from challenged chicks (seeders) to non-challenged broiler chicks (contacts). Data from the present study suggest that the spread of Salmonella from seeder chicks to contact chicks is dependent on the Salmonella challenge dose and not the number of chicks originally exposed. Horizontal transmission of Salmonella to unchallenged contact chicks from seeders initially challenged with 100 Salmonella or greater will limit the effectiveness of any post-hatchery Salmonella control program after they leave the hatchery.