Abstract: The purpose of this experiment was to investigate the effects of different intensities of monochromatic green light on hatching,embryo development,and early growth and development of chickens during incubation.810 New Pudong chicken eggs with similar size were randomly divided into 3 groups (n=270).The eggs were hatched in dark,low illumination (20~50 lux),or high illumination (200~300 lux) LED monochromatic green light (λ=525 nm) respectively during 1~18.5 days of incubation period,with 24 h light per day.From 18.5 days of incubation,the eggs of 3 groups were transferred to the same hatcher without light.Incubation temperature and humidity conditions were consistent among groups.The hatchability of fertile eggs,percentage of early dead embryo,body weight (BW) at birth and 10 weeks of age,serum hormones (thyroid hormone,calcitonin,growth hormone,melatonin and osteocalcin),and blood physiological and biochemical indicators (alkaline phosphatase,insulin-like growth factor and calcium of one-day-old and 3-week-old chicks) were examined.The results showed that 3 groups had similar early dead embryo number and percentage.At the 20.5 d after incubation,the hatchability of fertile eggs in the low illumination group and the high illumination group was about 2.3 times and 5.2 times of that in the dark group.At the 21.5 d after incubation,the hatchability of fertile eggs in the dark group was 82.8%.This parameter of the low illumination group and high illumination group was 6.5% and 1.9% higher than that of the dark group.The percentage of healthy chicks of dark group was 98.6%,this parameter of the low illumination group was 0.4% lower than that of dark group,while high illumination group and dark group was almost the same.The birth BW of males of the high illumination group was lower than that of the other two groups (P<0.05),but there was no difference between the low illumination group and the dark group (P>0.05).The trend of birth BW of females was basically consistent with that of males.The birth BW of female chicks in the high illumination group was lower than those of other two groups (P<0.05),and there was no difference between other two groups (P>0.05).At 10 weeks of age,there was no difference in BW between males or females of 3 groups (P<0.05).For the day-old chicks,there was no difference in blood and hormones indicators among groups (P>0.05).For the 3-week-old New Pudong roosters,the serum melatonin level(P<0.05)in the high and low illumination groups were higher than that in the dark group,and there was no difference in other indicators (P>0.05).In conclusion,compared to the dark condition,providing proper intensity of monochromatic green light during the incubation could promote the development of chicken embryo,and advance the hatching process without impairing chicks’health and following growth performance.

Key words: incubation; New Pudong chicken; monochromatic green light; light intensity; hormone