Which of the following is a comprehensive prevention measure for Salmonella enteritidis in chickens?

• A. Live vaccine for chicks; killed vaccine for laying hens; rodent/pest control; biosecurity/cleaning/disinfection
• B. Rodent/pest control
• C. Biosecurity/cleaning/disinfection only
• D. Live vaccine for chicks only

Answer: (A)

Prevention of Salmonella enteritidis in chickens relies on an integrated program that reduces both exposure and carriage across the flock’s life cycle. A live vaccine given to day-old chicks helps establish gut immunity early, lowering intestinal colonization and shedding during the grow-out period. A killed vaccine given to laying hens boosts immunity in birds producing eggs, helping reduce shedding in eggs and in the surrounding environment. Rodent and pest control is essential because rodents can carry Salmonella and contaminate feed, water, and surfaces, forming ongoing sources of infection. Biosecurity and cleaning/disinfection are foundational measures that limit pathogen introduction, control access, properly clean equipment, and perform disinfection between flocks to cut down environmental contamination and transmission risk. Taken together, these components create a comprehensive approach that addresses vaccination at different life stages, environmental reservoirs, and preventive practices; relying on any single measure leaves gaps for infection and persistence.