Chickens infected with Salmonella enteritidis at 1 day old will have persistent intestinal colonization, and by 24 weeks, about 50% will shed Salmonella enteritidis in their feces.

• A. True
• B. False
• C. Not proven
• D. Not enough data

Answer: (A)

Chickens infected with Salmonella enteritidis early in life tend to establish a lasting residence in the intestinal tract, especially in the ceca. Once the bacteria are established, they can persist for long periods because the gut environment and the immature immune system of day-old chicks allow the pathogen to remain without being cleared. As birds age, this intestinal reservoir can lead to continuous or intermittent shedding of Salmonella in the feces. By the time the birds reach production age, such as around 24 weeks, it is common for a substantial portion of the flock to shed Salmonella enteritidis in their feces—often estimated around 50%. This combination of persistent intestinal colonization and substantial shedding is why early infection is a major risk factor for long-term carriage and transmission within flocks.

So the statement is true because early infection commonly results in persistent intestinal colonization and a high likelihood of shedding later in the birds’ lives.