Submitted to: International Poultry Forum Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 10/10/2008
Publication Date: 1/26/2009
Citation: Hannah, J.F., Wilson, J.L., Cox Jr, N.A., Richardson, L.J., Cason Jr, J.A., Buhr, R.J. 2009. Eggshell bacterial contamination of non-washed and washed eggs from caged and cage-free hens. International Poultry Forum Proceedings. 88(S1):M12. P.136-137. Interpretive Summary:
Technical Abstract: This study was conducted to evaluate the microbiology of non-washed and washed table eggs obtained from caged and cage-free laying hens housed on either all shavings or all wire slat environments. Both Hy-Line W-37 white and Hy-Line brown strains were used. On each of four replication sample days (at 24, 28, 32, 36 wk of age), 20 eggs were collected from each pen for bacterial analysis (n=120). Ten of the eggs collected from each pen were washed for 1 min with a commercial egg washing solution (50 C, pH 11), 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 4.4 and coliforms 1.1 log10 cfu/mL) than eggs produced on slats (APC 3.9 and coliforms 1.1 log10 cfu/mL), which had significantly higher (P< 0.05) bacteria numbers than eggs produced in cages (APC 3.2 and coliforms 0.7 log10 cfu/mL). The washing of eggs from hens in cages, on shavings, and on slats significantly reduced APC counts by 1.1, 1.7, and 1.7 log10 cfu/mL of rinsate, respectively. E. coli and coliform counts were not influenced by housing type and were not significantly reduced by washing. Laying hen strain had no effect on eggshell bacteria recovery levels. No significant differences were found in APC, E. coli, and coliform counts on eggs obtained from the three housing types following washing. These results indicate that eggshell bacteria levels are similar following washing for eggs from hens housed in these cage and cage-free environments.