2009 Annual Report
This project is related to Objective 2 of this in-house project: This research quantifies the bacteria levels recovered from table eggs produced in three laying environments prior to and following eggshell sanitization and has implication for foodborne pathogens associated with table eggs.
The bacteria levels of non-washed and washed eggs obtained from caged and cage-free hens housed in either all wire slats or all shaving-covered pens were determined over an 8 month production period. On each sample day (from 22 to 52 wk), 20 eggs were collected from each pen (n=120/sample day). Ten eggs/pen were washed for 1 min with a commercial egg washing solution (50 C, pH 11, 5 psi), while the remaining 10 eggs were not washed prior to sampling the eggshell and membranes (crush-and-rub) for aerobic bacteria (APC), Escherichia coli (E. coli ), and coliforms. Non-washed eggs produced in an all shavings environment had slightly higher bacteria numbers (APC 4.0 and coliforms 1.1 log10 cfu/mL of rinsate) than eggs produced on slats (APC 3.6 and coliforms 1.0 log10 cfu/mL), which had significantly higher bacteria numbers than eggs produced in cages (APC 3.1 and coliforms 0.88 log10 cfu/mL). Washing significantly reduced APC counts by 1.7 log10 cfu/mL, and APC prevalence was reduced from 100, 99, and 98% (shavings, slats, and cages, respectively) to 87% for shavings and to 68% for caged and slat hens. Washing significantly reduced coliform counts by 0.5 log10 cfu/mL and prevalence was reduced from 22.5, 17.5, 12.5% (shavings, slats, and cages, respectively) to 6%. No significant differences were found in APC, E. coli, and coliform counts on eggs from the three housing types after the eggs were washed. These results indicate that eggshell bacteria levels are similar following washing for eggs from hens housed in these cage and cage-free environments.
Scientist attended and participated in monthly meetings and facilities visits to discuss and monitor research activities.