Stroke is an abrupt interruption of constant blood flow to the brain that causes loss of neurological function. The interruption of blood flow can be caused by a blockage, leading to the more common ischemic stroke, or by bleeding in the brain, leading to the more deadly hemorrhagic stroke.
Most ducks do not start laying eggs until they are between 9-11 months old. Depending on the breed they can lay year round. A duck will lay an egg a day until they have a clutch, between 8-15 eggs and then the mother will sit on them.
Tipically, a well fed chicken, with proper living conditions and from a good breed (such as Isa Brown) should start laying eggs at week 19 or 20. It will reach its peak of production between week 25 and 30, then it will decline but the bird will keep laying eggs until a very old age.