Effect of photoperiod on live performance in broiler chicks from placement to 14-days-of-age

Abstract

Lighting programs for broilers have traditionally employed continuous or near-continuous photoperiods through the first week of life to ensure chicks can successfully navigate the rearing environment for feed and water. Normal melatonin production and ocular development require a minimum of 4 h of darkness, yet photoperiod research in broilers has not typically examined the first week. This study examines the effect of a longer dark phase (scotophase) applied during the first 7 d post-hatch on live performance. A total of 384 Ross 708 broiler chickens were reared in 2 trials to 14 d of age using 2 different lighting program treatments (20L:4D vs. 23L:1D) applied from day-of-hatch. No significant differences were observed between treatment groups for live performance parameters including body weight (BW), body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR). Crop fill rates were also assessed, and no significant differences were observed. Increased scotophase length may be implemented as early as day-of-hatch without any compromise in performance.