Durability of alkaline agents' bactericidal efficacies in litter under field conditions.

Alkaline agents are well-known for their disinfection capacities against pathogens even at the presence of organic materials, but the durability of their bactericidal efficacies under field conditions is unknown. Therefore, within the present study, two alkaline agents, namely bioceramic (BCX) derived from chicken feces and food additive grade Ca(OH)2 (FdCa(OH)2) derived from natural lime stone, were evaluated for the persistence of their bactericidal efficacies in litter, under simulated field conditions. BCX powder mixed at 50% concentration in litter or FdCa(OH)2 powder at 20% concentration in litter lost their bactericidal efficacies at 3 days post exposure of chicks, and thereafter, both mentioned alkaline agents could not inactivate bacteria down to the acceptable level (≥3 log10 CFU/ml reduction).

Accuracy of the evaluation method for alkaline agents' bactericidal efficacies in solid, and the required time of bacterial inactivation.

An alkaline agent, namely food additive grade calcium hydroxide (FdCa (OH)2) in the powder form, was evaluated for its bactericidal efficacies in chicken feces at pH 13. The point for this evaluation was neutralization of the alkaline agent's pH at the time of bacterial recovery, since otherwise the results are substantially misleading. Without neutralization of the FdCa (OH)2 pH, the spiked bacteria were killed within min at the time of recovery in aqueous phase, but not in the solid form in feces, hence, it has been demonstrated that when bacteria were in solid, it took longer time than in liquid for the alkaline agent to inactivate them down to the acceptable level (≥3 log10 CFU/ml).

Virucidal Properties of Bioceramic Derived from Chicken Feces pH 13 and its Stability in Harsh Environments.

Bioceramic derived from chicken feces (BCX) is a material produced by a sintering process for the purpose of use in animal farms to control livestock infectious diseases. In the present study, BCX at pH 13 was evaluated for the durability of its virucidal activity in simulated field conditions. First it was shown that BCX had activity toward Newcastle disease virus, infectious bursal disease virus, and goose parvovirus within 3 min and toward avian influenza virus (AIV) within 1 hr. BCX was further tested by keeping it under simulated harsh environmental conditions with sunlight for several weeks as well as by repeatedly soaking it with water and drying under sunlight many times. After sampling every 2 consecutive weeks and every 2 (of 9) consecutive resuspensions, BCX was evaluated for its efficacy against AIV. Evaluation under the harsh conditions illustrated that BCX could retain its satisfactory efficacy toward AIV throughout 7 wk and through 9 resuspensions. It is hence concluded that BCX is an excellent material for applying in livestock farming as a trapping disinfectant, due to its efficacy to inactivate various viruses, and that this efficacy is prolonged even under harsh environmental conditions.

Inactivation of bacteria on surfaces by sprayed slightly acidic hypochlorous acid water: in vitro experiments.

The capacity of slightly acidic hypochlorous acid water (SAHW), in both liquid and spray form, to inactivate bacteria was evaluated as a potential candidate for biosecurity enhancement in poultry production. SAHW (containing 50 or 100 ppm chlorine, pH 6) was able to inactivate Escherichia coli and Salmonella Infantis in liquid to below detectable levels (≤2.6 log10 CFU/ml) within 5 sec of exposure. In addition, SAHW antibacterial capacity was evaluated by spraying it using a nebulizer into a box containing these bacteria, which were present on the surfaces of glass plates and rayon sheets. SAHW was able to inactivate both bacterial species on the glass plates (dry condition) and rayon sheets within 5 min spraying and 5 min contact times, with the exception of 50 ppm SAHW on the rayon sheets. Furthermore, a corrosivity test determined that SAHW does not corrode metallic objects, even at the longest exposure times (83 days). Our findings demonstrate that SAHW is a good candidate for biosecurity enhancement in the poultry industry. Spraying it on the surfaces of objects, eggshells, egg incubators and transport cages could reduce the chances of contamination and disease transmission. These results augment previous findings demonstrating the competence of SAHW as an anti-viral disinfectant.

Calcinated egg shell as a candidate of biosecurity enhancement material.

Calcinated egg shell (Egg-CaO), of which the main component is calcium oxide, was evaluated in the forms of powder and aqueous solutions for their efficacies as disinfectants against avian influenza virus (AIV), Newcastle disease virus (NDV), infectious bursal disease virus (IBDV), Salmonella Infantis and Escherichia coli. Egg-CaO powder inactivated these viruses within 3 min in the presence of 33% of fetal bovine serum (FBS). In Egg-CaO solutions, except AIV, all pathogens were inactivated within 1 hr, even in the presence of 5% of FBS. Without FBS, all pathogens, except AIV, were inactivated within 3 min, and AIV within 1 hr. In addition, persistence of virucidal activity against AIV and NDV of Egg-CaO powder was confirmed after exposure to sunlight for 2 weeks or resuspension with water for 7 times, simulating field harsh environments. Chick growth test was conducted to ensure the safety of the use of Egg-CaO powder in chicken cages and showed that it is safe to add Egg-CaO in litter or feed. In conclusion, Egg-CaO can be useful for the enhancement of biosecurity at farms.