Submitted to: Georgia Poultry Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 8/27/2010
Publication Date: 9/29/2010
Citation: Spickler, J.L., Buhr, R.J., Cox Jr, N.A. 2010. Comparison of the rinse and crush-and-rub eggshell sampling for aerobic bacteria of broiler hatching eggs after treatment with commercial sanitizers. Georgia Poultry Conference Proceedings.
Technical Abstract: The goal of this study was to compare surface and deep shell aerobic bacteria recovered by eggshell rinse and crush-and-rub methods for commercial hatching eggs after treatments with various sanitizers. Eggs were arranged into 5 treatments consisting of three sanitizers, Water, and No-treatment. Sanitizer treatments were Hydrogen Peroxide (H2O2), Phenol, and 4 quaternary ammoniums +1 biguanide biocide (Q4B). Eggs were sprayed according to treatment group and allowed to dry for 1 hour before sampling. To collect samples for the rinse, each egg was massaged in a plastic bag with 20 mL saline. Eggshells were then aseptically cracked, the contents discarded, and individually crushed into 50 mL centrifuge tubes also containing 20 mL of saline. Aerobic bacteria were enumerated on Petrifilm after 48 hours incubation at 37'C. Aerobic bacteria recovered from the rinse were highest and similar for No-treatment at 4.03alog10cfu/mL rinsate and for Water 3.73a, lower for Phenol 3.21b, H2O2 3.12b, and lowest for Q4B 2.42c. The crush-and-rub means for No-treatment 2.50alog10cfu/mL and for Water 2.32a were similar, and lower for Phenol 1.64b, and H2O2 1.19bc, and lowest for Q4B 0.88c. The overall correlation between the rinse and crush-and-rub sampling for aerobic bacteria counts was high at r2 = 0.71, P<0.0001. The correlation performed within each treatment to determine the presence of a relationship between the rinse and the crush-and-rub methods revealed the following R2 values; No-treatment 0.55, Water 0.72, H2O2 0.67, Phenol 0.73, and Q4B 0.38. The significantly lower correlations for the No-treatment and the Q4B indicate larger variances in aerobic bacteria recover levels from rinse and crush-and-rub methods from individual eggshells than were recovered in the other treatment groups. For the No-treatment, the lower correlation of 0.55 reveals the greater variability in the aerobic bacteria levels collected in the rinse samples, since the eggshells had not been wet and no washing-off of or killing of bacteria had occurred prior to sampling. For the Q4B treatment, the low correlation of 0.38 reveals the low variability as well as low levels of aerobic bacteria recovered in the crush-and–rub rinsates, indication that Q4B is a very effective sanitizer on broiler hatching eggs.