Intermittent lighting increases egg weight and facilitates early photostimulation of turkey breeder hens

A major limitation to reducing the age at photostimulation of turkey breeder hens has been small egg size, especially at the start of lay. The present study was designed to determine whether intermittent lighting (IL) could be used to photostimulate hens at an early age (26 wk) and enhance the typical small egg size at the start of lay. Control hens were photostimulated with standard [16 h light (L):8 h dark (D)] lighting at 26 or 30 wk of age. An additional group of hens was photostimulated with IL (2L:12D:2L:8D) from 26 to 32 wk of age and then switched to 16L:8D thereafter. Data were collected for BW, onset of lay, egg production, and egg weight to 54 wk of age. Although IL delayed onset of lay there was no adverse effect on rate of lay because numbers of eggs per hen in 24 wk of photostimulation (30 to 54 wk of age) were similar to that of controls. However, because hens in the IL treatment were photostimulated at 26 wk of age they produced about 10 more eggs per hen (P = 0.18) to 54 wk of age than control hens photostimulated at 30 wk of age. In addition, IL increased egg weight during the first 7 d of lay by about 5% as compared to those of controls also photostimulated at 26 wk of age. Interestingly, the increased egg weight in the IL treatment persisted to the end of lay, well after IL had been switched to 16L:8D. Thus, IL lighting facilitated successful early lighting of hens.