Salmonella contamination of hatching and table eggs: a comparison.

This study determined and compared Salmonella contamination rates of pools of surplus, early and culled hatching eggs from layer and broiler breeder flocks, and of pools of early and regular table eggs from layer flocks. Each pool contained 6 eggs. Five methods were used for the isolation of Salmonella. Nine of 126 pools of culled layer hatching eggs, 2 of 126 pools of surplus layer hatching eggs, and one of 126 pools of early layer hatching eggs were contaminated with Salmonella. All 126 pools of broiler breeder surplus, and early and culled hatching eggs tested negative for Salmonella. All 168 pools of regular table eggs tested negative for Salmonella, whilst one of 84 pools of early table eggs contained Salmonella agona. The pools of culled layer hatching eggs and surplus layer hatching eggs that contained S. typhimurium were derived from the same breeder operation. Similarly, the pools of culled and early layer hatching eggs that contained S. heidelberg were derived from one breeder operation. Pools of culled hatching eggs were more frequently contaminated with Salmonella than other hatching or table eggs. Pools containing eggs that were both cracked and dirty were more frequently contaminated with Salmonella than all other pools of eggs. The overall Salmonella contamination rate of the table eggs was 0.07 to 0.4%. Critical control points (macroscopic classification of the eggs as cracked and dirty) were validated microbiologically.