Submitted to: Applied Poultry Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 23, 2000
Publication Date: N/A
Interpretive Summary: The hatchery and breeder flocks have been recognized as a critical control point for entry of Salmonella into broiler flocks. Chemical disinfection of the fertile hatching egg is one approach to reduce Salmonella contamination in broilers and ultimately human exposure to Salmonella. This study describes a means to maximize the effect of a chemical by applying a vacuum and a surfactant to allow the chemical an opportunity to penetrate deeper into the egg to kill the invading Salmonella. These data provide the poultry industry with some practical information about how to improve the effectiveness of chemical disinfection of fertile hatching eggs.
Technical Abstract: Hydrogen peroxide (H2Os, 1.4%) has been shown to be an effective disinfectant to reduce Salmonella artificially inoculated onto hatching eggs. The objective of the present study was to determine if the efficacy of H2O2 could be enhanced by utilizing vacuum and a surfactant. Eggs were inoculated with nalidixic acid-resistant Salmonella Typhimurium and treated in groups of 10; 4 replications were done for each treatment. Inoculated eggs were submerged in either: 1.4% H2O2, 1.4% H2)2 with 0.0005% Triton x 100 (TX), water, or water with 0.0005% TX in a stainless-steel tub. Eggs were either treated in a vacuum chamber (-44 Kpa 4 min followed by atmospheric pressure 6 min) or left at atmospheric pressure for the same length of time. Following treatment, the shell and membranes were cultured for our marker Salmonella. Ninety five percent (38/40) of the eggs treated with water and TX remained positive for Salmonella in both the atmospheric pressure and vacuum groups. When H2O2 was positive. Addition of the vacuum 40% (16/40) of the eggs remained positive. Addition of the vacuum step made the disinfection more effective, but still 12/40 eggs (30%) remained positive. Results demonstrate the difficulty involved in reaching and killing Salmonella that have penetrated the hatching egg within 2 hours after contamination, even with an effective bactericide. Hatchability was not adversely affected with any of the treatments in this study.