Short Total Photoperiods and Egg Production of White Leghorns

Pilot experiments with replicates of 15 hens each showed that neither egg production, egg weight, shell breaking strength nor feed efficiency were adversely affected by light regimes of 2L:10D:2L:10D or 2L:12D:2L:8D in comparison with a light regime of 16L:8D. In larger scale experiments, under practical conditions, a light regime of 8L: 10D: 1/2L:5-1 /2D resulted in egg production, egg weight, shell breaking strength and feed efficiency which were not different from those obtained under 14L:10D. With the schedule in which the total duration of light exposure is 4 hours per day potential savings in the range of 100 × 106 kw. /hr./year could be accomplished nationally if such a lighting schedule were used.