Research Of LED Light Stimulation For Chicken Embryo And Light Transmittance Of Eggshell During Incubation

During the artificial incubation, there are five elements for embryo development: temperature, humidity, oxygen concentration, oxygen dioxide concentration, egg turning frequency. During the natural hatching, embryo development can be influenced by natural light when the hens leave the nest. However, in the modern industrial, incubation time was nearly to one third or one half and the chick performance are very important for late production performance. In the past years, more attention has been given to study the relationship between embryo development and light stimulation. More research have been reported that embryo development can be influenced by light stimulation. In this research, Light-emitting diode (LED) monochromatic green light (525nm±15nm) was used for the broilers (light pigment eggshell) and hens (dark pigment eggshell) eggs incubation with different light intensities and light period. Lights were arranged on the both sides for light stimulation which can be used for energy saving. Hatchability, embryo development, chick development performance and stress resistance were evaluated. Exploratory study of the different eggshell color for light incubation, photopermeability and changes of the elements, were performed to strengthen the theoretical research as incubator research foundation. The details are as follows:(1) Different monochromatic green light intensities for embryo developmentTwo light lamps was arranged on both sides of the incubator for incubation. Light can be irradiated form the sides to the middle and energy can be effectively utilized to reduce the cost. In this section, three light intensities (low:22-75 lux; middle:92-208 lux; high:150-392 lux) were used for Lingnan Yellow broilers incubation and hatchability and embryo development were evaluated. The results indicated that Lingnan Yellow broilers embryo development can be influenced by light stimulation. Embryo weight and organs weight were obviously increased and reduced hatching time. The mortality can also be reduced and the hatchability, growth hormone level and chick performance can also be improved. Among the treatments, low light (22-75 lux) was the best and middle and high treatments decreased the performance, even causing side-effect. In all, low light stimulation (22-75 lux) can be used for the improvement of hatchability and embryo development.(2) Different intensities green light for embryo and breeding development and stress resistanceThree intensities green LED light (low:22-75 lux; middle:92-208 lux; high: 150-392 lux) were used for egg incubation of Hy-Line Brown layers. Hatchability, embryo development and stress resistance were evaluated and the results showed that high light (150-392 lux) stimulation can be used for layers egg incubation with the improvement of hatchability and decrease of the mortality. When low light (22-75 lux) stimulation was used, embryo weight and body length can be obviously increased on day 13 and 15. The development of organs(heart, liver and digestive system) of the young chick can be improved by the green LED light stimulation. Low light treatment (22-75 lux) can improve the T3 and T4 level in serum on H14, and better improvement was observed on female chick than male chick. The value of lonely test and emergency delay test can be reduced when the low intensity green light was used for incubation. Middle and high intensities (92-208 lux,150-392 lux) stimulation can influenced the lateralization. All the results showed high intensity green LED stimulation (150-392 lux) can increase the embryo development and hatchability and improve the stress resistance.(3) Different photoperiod for the embryo development and hatching growthThe same light intensity (150-392 lux) was used to evaluate the effect of different photoperiod by the comparison of embryo development and growth.338-992 lux light intensity was identified for the embryo development and growth. Two LED lamps were also used for the irradiation from the sides to the middle. The results declared that green LED light stimulation can obviously improve the embryo eye, tibia length and mouth development and organs development in hatching time. The hormone level can also be improved during breeding time. In all, the day 0-7 green LED photoperiod was observed better performance compared with other photoperiods with higher hatchability and hatch performance and better embryo and organs development.(4) Research of light percent transmittance (PT) for chicken eggshells with different intensities of pink pigment during incubation periodThe objective of this study was to investigate changes in pigment, spectral transmission and element content of chicken eggshells with different intensities of pink pigment during incubation period. We also investigated the effects of the region (small, equator and large pole) and pink pigment intensity of the Meihuang chicken eggshell on the percent transmittance of light passing through the chicken eggshells. Compared with other regions and pigment intensities, eggshell at the small pole and with light pigmentation intensity showed a highest percent transmittance of light. And the transmittance value varied significantly with incubation time. In summary, the pigment intensity and the region of the eggshell influenced the PT of the eggshell. Differences in the spectral characteristics of different eggshells may influence the effects of photostimulation during the incubation of eggs. All of these results will be applicable for perfecting the design of light intensity for lighted incubation to improve productivity.