Effect of Intermittent Lighting on Production Performance of Laying-Hen Parent Stocks

The objective of this observational field study was to investigate the effect of an alternative intermittent lighting program (13L: 5D: 1L: 5D – Trt) vs. standard lighting program (16L: 8D – Ctrl) on production performance of laying-hen parent flocks. Two houses of 15,000 Hy-Line brown parent-stock hens each were used for the comparative study. Hen-day egg production (HDEP), eggs per hen housed (EHH), hen-day hatchable egg production (HDHEP), hatchable eggs per hen housed (HEHH), percentage of crack eggs, feed use, and hen mortality were recorded from 18 to 58 weeks of age. At 35 weeks of age, distributions of egglaying time within the day and egg weight were monitored for three consecutive days. Light intensities at three (top, middle, and bottom) tier levels were measured at 36 weeks of age. HDEP of Ctrl and Trt regimens (mean ±SD) was 65.4±4.5% and 67.5±5.6%, respectively; and EHH was 146 and 153, respectively. HDHEP of Ctrl and Trt was 43.8±4.8% and 44.4±7.19%, respectively; and HEHH was 70 and 74, respectively. Crack eggs were 0.97±0.38% under Ctrl and 0.87±0.38% under Trt. Feed intake was similar for Ctrl (109±8 g hen-1 d-1) and Trt (105±9 g hen-1 d-1). Weekly mean mortality was 0.282±0.185% for Ctrl and 0.119±0.053% for Trt. Light intensities were significantly different among the top (18.7 ± 5.8 lux), middle (13.7 ± 5.0 lux) and bottom (11.3 ± 6.4 lux) tiers (P<0.01). Egg weight for the bottom tier was closer to the standard egg weight and was greater than that for the top or middle tier (P<0.05) in the Trt house, although significant difference was not observed in the Ctrl house. These field observational results indicate that the Trt lighting regimen has the potential to save lighting energy without compromising egg production performance of the hens. However further studies are needed to verify the findings.