Food intake and oviposition by domestic fowl under symmetric skeleton photoperiods

Abstract

1. Under a symmetric skeleton photoperiod of 2 h light, 10 h dark, 2 h light and 10 h dark (2L : 10D : 2L : 10D), most ovippositions occurred in the first 10‐h dark period with an important mode during the first hour of darkness.

2. With a gradual increase of the first dark period (the period of activity), the ovipositions become increasingly spread throughout the 24‐h cycle; a complete phase shift for the timing of oviposition was observed with the programme 2 h light, 11 h 15 min dark, 2 h light and 8 h 45 min dark (2L : 11.15D : 2L : 8.45D).

3. With the photoperiod 2L : 10D : 2L : 10D, the servicing of the birds during either 2‐h light period, and the withdrawal of calcium source during either the second 2‐h light period or during the first 10‐h dark and second 2‐h light periods did not change the timing of ovipositions.