• After 7 days of age around 5 hours of darkness may be optimum (4-6 hours).
• There is no reduction in growth rate to 39 days and possibly an increase to 49 days of age. Feed
conversion efficiency improves particularly in the later stages of growth.
• Mortality due to sudden death syndrome (SDS or flips) and mortality and morbidity from ascites and
skeletal disorders are reduced.
• Bird mobility is improved and the severity of footpad lesions may be reduced.
• The proportion of meat as leg meat may be increased.
• The welfare of the birds is improved as a more normal biological rhythm including rest is facilitated.