Cycle:
The spores of the Aspergillus fungus are like tiny dry seeds that can easily spread through air currents or the wind.
The spores are found in small amounts throughout the environment, and they can survive and grow in a wide range of conditions, but especially in organic matter, such as egg yolk, cardboard boxes, and untreated wood.
Spore growth was initiated by conditions of high humidity and temperature (37–45 °C).
Cycles of high temperature and high humidity optimize the growth of the fungus (mycelium) and the diffusion of its spores.
The breeding facility, or chicken coop, therefore provides optimal environmental conditions for Aspergillus to thrive.
Aspergillus spores can enter when the incubator environment is contaminated with high levels of Aspergillus; the spores can easily enter the unit through the ventilation system.
The climate, temperature, and humidity in ventilation ducts are ideal for the growth of Aspergillus, especially when organic matter (debris) has accumulated.
The main route in the hatchery to the spores of Aspergillus, however, it is usually through contaminated eggs.
Aspergillus spores attached to the outer shell find their way into the egg white and yolk through hairline cracks or fissures in the shell.
Egg yolk is an ideal growth medium for Aspergillus, and once the spores have entered the eggs, they can spread throughout the incubator.
The nests also contain several sources of Aspergillus, including beds, manure and feed.
The eggs from the nests, therefore, can become contaminated by contact with the spores of Aspergillus. Eggs on the ground as well, of course, have a high risk of being contaminated.
Initially, the Aspergillus infection was found during the routine analysis of unhatched eggs.
Infected eggs show visible mold on the air cell membrane. The risk of a severe Aspergillus bloom is high when 0.5 percent of hatching eggs show clear signs of infection with visible fungal growth. In addition, the rate of embryo mortality around 16 days is higher than expected.
Prevention:
It is the first line of action. To prevent infection by Aspergillus in the incubator and the chicken coop, the measures that are recommended are:
—Do not incubate eggs on the floor.
—Do not incubate broken eggs or eggs with cracks.
—Avoid wood, walls, ceilings, or other surfaces in the incubation room, as Aspergillus thrives on untreated wood.
—Regularly inspect unhatched eggs, and if any are found to be infected, take steps to identify the sources of Aspergillus.
—Ensure that incubation sanitation is fully maintained.
—If mold is found, take immediate steps to clean the incubator.
—Make sure the incubator and the ventilation ducts are clean and disinfected.
Remember that incubation equipment must first be free of all organic matter before disinfection can take place.
It makes no sense for the disinfection of equipment, trays or boxes, where wastes remain stuck to the surface.
If you Aspergillus was found in the chicken coop, the following is recommended:
- Apply the fungicide at a regular interval because the spores of the Aspergillus species are highly resistant to fungicides.
- Any surviving spores will develop into mature, spore-producing mold, so the fungicide must be applied before this stage of development.
- Identify and eliminate the source of Aspergillus spores; the primary sources—which are commonly found on breeding farms—include nesting boxes (made of wood), litter, cardboard boxes, and untreated wooden walls and ceilings.
