Light is an important environmental factor that can influence the incubation performance in chickens. However, in commercial hatcheries, eggs are incubated without light, which differs from the principle of natural incubation. The influence of light during incubation can affect embryogenesis and the post-hatch performance in poultry. This study assessed the impact of different intensities of dichromatic light during incubation on post-hatch growth performance, behavioral changes, immune response, and welfare traits in chickens. For this, a total of 1000 eggs from broiler (Ross-308) and layer (White Bovans) breeders (age 43 weeks) were incubated under 4 different lighting intensities of Green-Red dichromatic light for 12 hours/day during the whole incubation period, i.e. Darkness, 150 lux, 250 lux, 350 lux. Results indicated that broilers that were incubated under lighting gained significantly higher body weight (p ≤ 0.05). Whereas, the bursa weight percentage was higher in broilers compared to layer birds (p = 0.001). Moreover, tonic immobility was significantly better (p = 0.033) in broilers incubated in 350 lux light intensity. However, welfare traits such as physical asymmetry and vocalization were not affected by light during incubation. Behavioral analysis of birds on the 1st, 7th, and 14th-day post-hatch showed that layers were more active and showed significantly higher activity in walking and dust bathing (p ≤ 0.05). It can be concluded that light during incubation affects the post-hatch performance, and if eggs are provided with 350 lux light during incubation, subsequent growth performance and immune response can be improved.
Riaz et al. (2026) studied this question.