The present experiment was carried out to study the role of spraying hatching eggs with natural disinfectants on hatching characteristics and eggshell bacterial counts. Seven hundred females with seventy males from Gimmizah chickens aged 45 wk were housed in floor pens. Hatching eggs produced from Gimmizah hens were collected four times a day and subjected to disinfection within the first four hours after laying. Two thousand and one hundred hatching eggs were divided into seven treatment groups. Eggs of first and second groups were sprayed by propoplis 7% and 14%, respectively. The third and the fourth groups were sprayed by thyme oil 0.5% and 0.7%, respectively. The fifth group was sprayed by ethyl alcohol 70%, the sixth group was subjected to formaldehyde fumigation for 20 minutes (119.8ml formalin and 59.9gm potassium permanganate /2.83m3) and the seventh eggs group was considered as control (untreated).
Results obtained are summarized as follows:-
1- Spraying the eggs with propolis 14% and thyme oil (0.5 and 0.7%) significantly decreased egg weight loss percentage during the setting phase compared with the other experimental disinfectants, fumigation and control.
2- Highest significant percentages of embryonic mortalities during the whole incubation period (O-pipping) were observed for eggs disinfected with ethyl alcohol and control untreated groups, whereas the lowest ones were detected for eggs disinfected with both concentrations of propolis (7 and 14%) and formaldehyde fumigation.
3- Hatchability percentages were significantly increased for both propolis concentrations and formaldehyde fumigation.
4- The heaviest chick body weight at hatch and at pull out were recorded for chicks produced from group treated with propolis 14% compared with those produced from other egg treatments.