Experiment on flusher-disinfection effect by slightly acidic electrolyzed water in poultry hatcheries

Abstract: Regular flusher-disinfection in hatcheries is an important measure to prevent epidemic diseases. However, traditional chemical disinfectants used in hatcheries can cause toxic residue, low disinfection effect and bacterial resistance. In practical production of hatchery, the traditional clean-in-place including three parts: 1) surface of the inside wall of the hatcher, 2) surface of the floor, 3) surface of the hatching basket. The flusher-disinfection durations were set 4 min for the surface of the inside wall of the hatcher and the floor and 40 s for the surface of the hatching basket with traditional chemical disinfectants (povidone-iodine solution or benzalkonium bromide solution) to reduce the number of bacterial microorganisms and maintain good hygiene condition. Slightly acidic electrolyzed water (SAEW, pH=5.0-6.5) is proved to be a broad-spectrum, high-efficiency, low corrosive, residue-free, and environment-friendly disinfectant, which could be a potential alternative disinfection of the traditional chemical disinfectants. Aiming at finding an optimal of using SAEW in cleaning hatcher and reducing cleaning costs, an experiment with three components: bacterial distribution on the surface of the hatching equipment, germicidal efficacy of various disinfectants, and the effect of disinfection time on the sterilizing rate were conducted. Surface swabbing was used to sample the total bacteria, Escherichia coli, and Staphylococcus aureus on the surface of the inside wall, floor, and hatching basket of the hatching equipment. SAEW with the concentrations of 60, 80, and 100 mg/L, as alternative disinfections of flusher disinfection, were chosen to compare with two traditional chemical disinfectants (povidone-iodine solution and benzalkonium bromide solution) by single-factor test. In the study of the effect of disinfection time on the sterilizing rate, disinfection durations were set as 1, 2, 3, 4, 5 min for the surface of inside wall and floor, and 10, 20, 30, 40 s for the surface of hatching basket, respectively. high-pressure water jet with nozzle orifice diameter of 2.2 mm operated at 3.5 MPa was used in the whole cleaning process. The results showed that flusher-disinfection using 60-100 mg/L (available chlorine concentration, ACC) slightly acidic electrolytic water could effectively reduce the total bacteria (total aerobic bacteria), Escherichia coli and Staphylococcus aureus on the surface of the inside wall and floor in hatcheries, and the surface of hatching basket. The bactericidal effect increased with the increase of ACC and treatment time. The total bacteria sterilization rates were 93.9% and 85.6% by flusher-disinfection using 100 mg/L SAEW at the duration of 3 min for the surface of the inside walls and floor of hatchers, respectively, which was significantly higher than using 50 mg/L povidone-iodine solution or 50 mg/L benzalkonium bromide solution (P<0.05). Flusher-disinfection using 100 mg/L SAEW for 40 s on the hatching basket surfaces could reach a sterilization rate of 79.6%. The bactericidal effect of flusher-disinfection in hatches could be improved by using SAEW which is also a broad-spectrum and non-residual disinfectant, and flusher-disinfection using SAEW can be an alternative to traditional chemical disinfectants used for disinfection in hatcheries.