Effect of Midnight Feeding on Performance and Production of Layer Hens Raised in Open House

Abstract

Midnight feeding (MF) has been shown to improve laying performance in closed-house systems; however, evidence under open-house conditions remains limited. This study evaluated the effects of MF on feed intake (FI), body weight (BW), egg production, egg mass, feed conversion ratio (FCR), and egg quality of laying hens reared in an open house. A completely randomized design was used with two treatments: 150 hens without MF (17L:7D; P0) and 150 hens with MF (17L:2.5D :2L:2.5D; P1). Treatments were initiated at week 24, with data collected from weeks 26 to 31. Statistical analysis was performed using an independent two-tailed t-test or Mann–Whitney U test according to data normality (P≤0.05). Midnight feeding had no significant effect on FI (approximately 118–122 g/day), BW (1705–1801 g), or Haugh unit (70–82) (P≥0.05). However, P1 showed significantly higher weekly egg production (WEP), reaching 70.93% vs. 56.44% in week 27 (P≤0.05). Eggshell thickness increased from 0.263–0.297 mm in P0 to 0.382–0.414 mm in P1 during significant weeks (P≤0.05). Egg mass was significantly higher in P1, for example 38.77 vs. 30.83 g/hen/day in week 27 (P≤0.05), resulting in improved FCR (3.06 vs. 3.84 in week 27; P≤0.05). These findings indicate that MF enhanced productive efficiency under open-house conditions without increasing feed intake or altering body weight and internal egg quality. Nevertheless, nocturnal photostimulation may influence circadian regulation, stress responses, and laying hen behaviour, particularly in tropical open-house systems.