Prevalence and Inhibition of Microbial Load on Chicken Eggs with Special References to Egg Quality and Hatchability

Abstract

A total of 304 random chicken egg samples obtained from layers of Balady and Battery systems. 144 of chicken Balady and Battery eggs (72 of each sample were divided into 18 batches) were used for bacteriological evaluation. Enterobactriacae (94.4, 33.3 and 27.7%), Salmonella (77, 29 and 22%), E.coli (44, 0 and 22%) and Staphylococcus aureus (100, 97 and 98%) were detected in shell, albumen and yolk in Balady eggs, respectively. Battery system showed lower incidence in Enterobactriacae (50, 16.6 and 22%), Salmonella (41.6, 8 and 0%), E.coli (27.7, 9 and 19%) and Staphylococcus aureus (100, 83 and 95%), respectively. Results concluded that the system in which the hens are housed contribute in rate of contamination of eggs. Staphylococcus aureus showed a higher prevalence rate compared to other pathogens in both laying systems. About 160 Balady eggs were selected for studying the effect of different pathogen inhibitors, 80 eggs for detecting preservation after 21 days at room temperature and the other 80 fertile Balady eggs for detecting hatchability and mortality. The efficacy of application of different pathogen inhibitors as Propionic acid at different concentration 10, 30, 50, 70 and 100%, Hydrogen Peroxides (H₂O₂) 3% and Virkon S 1% on eggs were recorded. Propionic acid10%, Virkon S and H₂O₂ showed nearly similar significant inhibitory effect on pathogens on egg shells ranged from 86 to 100%, albumin from 33.4 to 100% and yolk from 34.3 to100%, while 30% Propionic acid has highly significant inhibitory effect on pathogen load ranged from 99.8 to100%. About 30% propionic acid concentration had a preservative effect on table eggs for 21 days at room temperature and increasing hatching percent up to 90% and lowering embryonic mortality to10% in fertile eggs. The findings of this study indicate that 30% Propionic acid may be considered as a favorable disinfectant agent for the egg shell spraying.