Temporary Ahemeral Lighting for Increased Egg Size in Maturing Pullets

Abstract

Temporary, 28-h, ahemeral lighting (TAL) cycles were compared with conventional, 24-h, hemeral lighting (CHL) cycles in an attempt to increase initial egg size from maturing pullets without reducing performance. The parameters measured were: 1) sexual maturity [age at first egg, age at 50% production, age when egg weight (EW) ≥56.7 g (large size)]; 2) EW; 3) productivity [hen-day egg production (HDP), eggs per hen, egg mass per hen-housed]; 4) efficiency (feed per hen per day, feed per egg, g of feed per g of egg); 5) egg-shell quality (specific gravity); and 6) mortality. During Trial 1,22-wk-old New Hampshire pullets were exposed to 12 h of light (L): 16 h of dark (D) for 12 wk and then changed to a 16L:8D ratio. During the 32-wk production period, the only significant (P≤.05) difference between TAL and CHL was EW (56.1 versus 54.3 g, respectively). The TAL treatment in Trial 2 exposed 17-wk-old Leghorn pullets to 11L:17D until EW reached 56.7 g at 26 wk, when the L:D ratio was changed to 13L:13D for 1 wk, then to 15L:9D from 28 to 70 weeks of age. The TAL caused the pullets to produce large eggs 2 wk (P<.001) earlier than the CHL for the controls (15L:9D, 17 to 70 wk). During the 48-wk production cycle, TAL significantly increased EW (62.5 versus 60.9 g) and improved shell quality.In both trials, a reduction of HDP was observed during TAL; but long-term HDP was not significantly (P≤.05) affected. EW was permanently increased by TAL.