21. The extent to which the environment within the turkey house provides adequate comfort for the birds is important to their welfare. When turkeys are housed in large groups in buildings with controlled environments it is particularly important that the system satisfies the birds' requirements. An imbalance in any factor may affect welfare but the risk of the birds suffering distress usually occurs when a combination of environmental factors are outside acceptable limits. Whichever factor is considered, and only the most significant are mentioned in the following paragraphs, good management and good stockmanship are essential.