Effects of Exposing Eggs to Various Green Light Intensities during Incubation on Hatch Performance, Post-Hatch Grow Performance, Fear and Stress Responses in Layer Chicks

摘要

:Previous researches have indicated the improvement of incubation by green light stimuli. In this study, two LED lamps were installed on both edges of two egg trays and the irradiation was directed from the edges to the middle, which was employed to investigate effects of green LED light (514nm) with various light intensities on layer incubation. A total of1408 layer eggs were randomly allocated to high-light (300 Ix), middle-light (150 Ix), low-light (50 Ix), and dark treatments with four replicates. Hatch performance, post-hatch grow performance, fear and stress responses were tested, respectively. The results indicated that incubation of the layer eggs under an appropriate light intensity (high-light treatment) of green light increased embryonicgrowth and improved hatchability about 3%. The chicks of high-light treatment had heaviest viscera (liver: P<0.05, digestive system: P=0.07) compared with dark and other light treatments. Low-light treatment significantly improved the T3 (Triiodothyronin) and T4 (Thyroxine) level of chicks (P<0.05, P<0.001), and those performances of females were better than those of males. In fear and stress responses test, the chicles of light treatments performed better than those of dark treatment by decreasing times of vocalization and time of latency in insolation and emergence tests (P<0.05, P<0.05). Moreover, light affected the laterality of chicks in the emergence test, and right was preferred to the light treatments (P<0.001).