Comparison of Eucalyptus Extract and Formaldehyde on hatchability and Survival rate of chicks in Disinfection of fertile Eggs
To compare the effect of eucalyptus extract and formaldehyde gas on the hatchability, survival rate, and microbial load of embryos and biological biomarkers of embryos in the fertile eggs of broiler chicken, 120 fertile eggs were divided into four groups (each group contained 30 eggs). The studied groups included the first and second groups in which eucalyptus extract at concentrations of respectively 1.100 and 1.200 was used as a disinfectant, the third group in which formaldehyde gas was used as a disinfectant and the fourth group as a negative control in which the studied eggs were sprayed with distilled sterilized water without using any disinfectant. All eggs were kept in a standard incubation system and the hatching rate was determined after 21 days. The hatched embryos were cultured to identify infection with E. coli. The hatched chickens were monitored for one week, and survival rate and the amount of using grain, overweight, and food conversion ratios were studied in different groups. The results showed that the disinfection of fertile egg with eucalyptus extract at the concentration of 1.200 was similar to that of formaldehyde, while the eucalyptus extract at the concentration of 1.100 can increase the hatching rate and the growth indicators. Therefore, it seems that using eucalyptus extract in the appropriate conditions and concentrations can be an appropriate alternative for formaldehyde.