There are many sources of diseases as following:
- Entering sick chicks to the farm from the producer company to the farm those chicks come from sick mother chick with a vertical way.
- Or infection from neighbor farms
- Or from polluted eggs.
- Or because of human factors like hands, legs, polluted shoes, polluted clothes, visitors, guards which walk from farm to another.
- Ash – feather
- Pests like rodents, dogs, insects and gecko.
- Live vaccines.
- Polluted food.
- Old offal.
- Transportation and maintenance cars
- Water
- Air ( The design of farms should be with the wind direction )
- breeding different ages