Which of the following is a normal time frame for environmental testing for Salmonella enteritidis in laying hens?

• A. 40-45 weeks
• B. 4-6 weeks after molt
• C. 14-16 weeks
• D. 8-12 weeks

Answer: (C)

Environmental testing intervals are chosen to balance how quickly Salmonella can build up in the house environment with the practicality of routine surveillance. Salmonella enteritidis can be shed intermittently and persist in litter, cages, and on surfaces, so you want enough time between tests for contamination to reach detectable levels, but not so long that undetected contamination remains in the flock. About 14–16 weeks fits a typical laying-hen production cycle and provides a practical, cost-conscious surveillance interval that still allows timely intervention if results are positive. Shorter intervals after molt focus on a transition period rather than the steady-state environment of the laying flock, while much longer intervals increase the risk that contamination goes undetected; 8–12 weeks is possible in some programs but 14–16 weeks is the standard interval used in many guidelines.