Evaluation of propolis extract as a disinfectant of Japanese quail (Coturnix coturnix japonica) hatching eggs

This study was carried out to evaluate the effectiveness of an alcoholic propolis extract (15%) as a disinfectant for Japanese quail (Coturnix coturnix japonica) hatching eggs. A total of 600 eggs were randomly divided into four experimental groups: 1) negative control (NC), without disinfection, 2) control (C), fumigated with formaldehyde gas, 3) (A), sprayed with 96% alcohol, and 4) (P), sprayed with 15% alcoholic propolis extract. The eggs were incubated artificially in a BIOS hatching apparatus under standard conditions. On the 14th day, the eggs were candled to determine the number of infertile eggs and dead embryos and samples were collected for microbial analysis. After 17.5 d, fertility, hatchability, embryonic mortality, and eggshell conductance were calculated. Fertile eggs sprayed with propolis were shown to have a lower eggshell conductance constant (egg weight loss) than eggs from groups C and A. Total microbial activity on the eggshells did not differ significantly between groups, but Staphylococcus aureus, Micrococcus spp., Bordetella spp., and Chryseobacterium meningosepticum isolates were significantly affected by the propolis treatment. There were no significant differences between treatments for total hatchability, embryonic mortality, and chick body weight on the 1st, 7th, and 14th days of life. The total chick survivability during the first 2 wk was significantly higher in group P than in the other groups. The results indicate that spraying hatching eggs with 15% propolis as a disinfectant can be recommended as a safe and natural sanitizer in place of formaldehyde, with no negative effect on quail chicks.