The most common birds classified as breeding poultry are broilers, laying hens, turkeys, geese and ducks. In poultry farming, ensuring animal welfare is of increasing importance. The birds should be provided with the right conditions, which means dry, well-insulated enclosures and the right humidity. An important part of welfare is the reduction of unpleasant odours in livestock housing, storerooms or paddocks. Improved environmental and sanitary conditions are possible through the use of biopreparations that are safe for both humans and animals.