THE EFFECT OF 6-HOUR AND 8-HOUR LIGHT-DARK CYCLES ON EGG-PRODUCTION AND PATTERN OF OVIPOSITIONS

Two flocks of 60 laying hens were transferred from 14 h light (L):10 h dark (D), to repeated 3 L:3 D or 4 L:4 D lighting schedules at 37 wk of age. Egg production decreased slightly but egg weight and shell quality improved. The intake of low-Ca diet and of oyster shell were similar for each light period of each lighting regimen. Ovipositions were distributed virtually at random throughout the day and the mean interval between successive eggs within a clutch was increased. Reducing the total daily photoperiod from 12 to 6 h decreased daily food consumption.