Preventive measures in poultry farming are directed both to prevent the introduction of infection on to the farm and they also are intended for reduction of microflora existent indoors farm (hatchery), it means prevention of microbial fatigue environment in the hatcheries – chicken rearing – laying hens – broilers. Microbial fatigue environment can be manifested by both depression of growth and disruption of health state of animals. This is important not only in farms with a higher concentration of animals, but of course also in hatcheries with frequent variation of poultry populations where there is a high microbial load of space and its surroundings.