Timing of Light Exposure During Incubation to Improve Hatchability, Chick Quality and Post-Hatch Well-Being in Broiler Chickens: 21 or 18 Days

摘要

Providing light during incubation has been shown to hatchability and post hatch development; however, the optimal timing of this light is still not known. To determine if there is an effect of exposing embryos to light for the first 18 d of incubation or the entire 21 d of incubation, we incubated broiler chicken eggs (N = 3096) for either 18 d (18DL), 21 d (21DL) or not at all (DARK). Embryo mortality, chick weight, proportion of cull or dirty chicks, or those with leg or other abnormalities was not affected by incubation conditions (p>0.05). The DARK broilers had a lower hatch rate, a lower proportion of unhealed navels and no defect chicks than both the 18DL and the 21DL (p0.05) on 45 d weight gain or 45 d feed conversion . The DARK broilers vocalized more during isolation and had longer latency to right during tonic immobility than both the 18DL and the 21DL (p0.05). Hatchability, chick quality, fear response and stress susceptibility were all improved with lighted incubation irrespective if the lighting occurred for 18 or 21 days. Providing light during the first 18 d of incubation can improve production and bird welfare.