鸡胚胎期及生长发育早期对孵化绿光强度的反应

试验旨在探究孵化期单色绿光不同光照强度对鸡孵化和早期生长发育的影响。选用810个大小均匀的新浦东鸡种蛋，随机分为3组（n=270），孵化期1~18.5 d分别在黑暗、低照度（20~50 lux）和高照度（200~300 lux）的LED单色绿光（λ=525 nm）条件下孵化，每天光照24 h，各组种蛋于第18.5天转至同一台无光出雏器中，各组温度和湿度等其他孵化条件始终保持一致。检测各组受精蛋孵化率、死胚率、初生重、10周龄体重、初生雏鸡及3周龄公鸡的血清激素浓度（甲状腺素、降钙素、生长激素、褪黑激素和骨钙素等）和血液生理生化指标（碱性磷酸酶、胰岛素样生长因子和钙等含量）。结果表明：各组种蛋的死胚数和死胚率差异较小；孵化的20.5 d低照度组和高照度组的受精蛋孵化率分别为黑暗组的2.3倍和5.2倍；孵化的21.5 d黑暗组的受精蛋孵化率为82.8%，低照度组和高照度组的孵化率分别比黑暗组高6.5%和1.9%；黑暗组的健雏率为98.6%，低照度组的健雏率比黑暗组低0.4%，而高照度组与黑暗组的健雏率接近；高照度组公雏初生重显著低于黑暗组（P<0.05），而低照度组与黑暗组无显著差异（P>0.05）。母雏初生重趋势与公雏基本一致，高照度组母雏初生重显著低于其他两组（P<0.05），其他两组之间无显著差异（P>0.05）；在10周龄，各组公鸡和母鸡体重无显著差异（P<0.05）；各组1日龄公雏血液生理生化和激素指标无显著差异（P>0.05），3周龄公鸡高照度组和低照度组褪黑激素含量显著高于黑暗组（P<0.05），其他指标无显著差异（P>0.05）。综上，在种蛋的孵化过程中，与黑暗条件下相比，给予适宜强度的单色绿光能够促进鸡胚发育，在不影响雏鸡健康的前提下使出雏时间提前，孵化期光照对后期生长发育影响较小。

Response of Chickens’ Embryo and Early Growth and Development to Different Intensities of Green Light Stimulation During Incubation

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.