The Effects of Sunlight on Laying Hens 
As the days get shorter, egg production starts to decline. Hens need a certain amount of daylight in order to maintain peak egg-laying. A hen’s reproductive cycle is controlled by photoperiod, or light exposure. Hens require at least 14 hours of light per day to lay eggs. Chickens produce eggs at a maximum rate with 16 hours of light exposure. Once daylight is less than 12 hours, egg production slows down considerably if not ceasing completely.