Eggshell microbiology and quality of hatching eggs subjected to different sanitizing procedures

Abstract: The objective of this work was to evaluate the effect of different disinfection procedures as alternatives to formaldehyde fumigation on eggshell microbial load and quality of eggs from a 42-week-old Cobb commercial breeder flock. A total of 10,080 clean eggs collected from the nests were randomly distributed in a randomized complete block design, among the following treatment groups: 13.33 g m-3 formaldehyde fumigation, 5-10 ppm ozone fumigation, 6.36 mW cm-2 UV-C light irradiation, spraying with 1.56% hydrogen peroxide, spraying with 0.13% peracetic acid, spraying with water (wet control), and no disinfection procedure (dry control). Per treatment, eight samples of four eggs each were collected before and after the disinfection procedure, in order to count the number of Enterobacteriaceae and total aerobic mesophilic bacteria on the eggshell. Only eggs subjected to the formaldehyde and UV treatments showed a significant reduction in total aerobic mesophilic bacterial count on the eggshell, when compared with those of the dry control group. Treatments did not affect eggshell thickness and resistance force. UV light exposure is effective in reducing microbial load on 42-week-old breeder flock eggshells, without affecting their quality, and can be considered an alternative to formaldehyde disinfection.