Title: Egg Production of Chickens Kept in Darkness
Abstract: ALTHOUGH darkness allegedly inhibits egg production, our previous work (Wilson and Abplanalp, 1956) showed that pullets would lay eggs with a daily ration of six minutes of light in 24 hours. Rearing pullets in darkness does not prevent them from coming into egg production according to Rider (1938). Continuous darkness actually produced maximum testicular weight in the parakeet, Melapsittacus undulatus, in the experiments of Vaugien (1953). The purpose of these tests was to determine the length of time hens would remain in production when subjected to complete darkness. EXPERIMENTAL Two tests were made in which S. C. White Leghorn laying hens in cages spent a 5-week period in complete darkness. The first test was with 60 hens kept in three separate pens of 20 hens each. From 17 to 38 weeks of age these hens had been given alternately two hours of light and two hours of darkness. They had . . .