Study On The Nutrients Of The Substance Transportation And Utilisation Inside Eggs During Incubation

In current paper, 900 white-shell eggs with the basically similar condition were hatched. The temperature and relative humidity was set respectively at 38.0℃, 55% from the 1st day to the 19th day and 37.5℃, 70% from 20th day to 21st day. 70 eggs were picked out randomly at the 0, 2nd, 4th, 6th, 8th, 10th, 12th, 14th, 16th, 18th, 20th, 21st day for studying: (1) the changes of the water content during incubation; (2) the changes of the content of calcium and phosphorus in the eggshell, albumen, yolk and the embryo; (3) the changes of the content of crude protein, crude fat and the energy during the incubation; (4) the changes of the content and the PH of amniotic and allantoic fluid; (5) the changes of the physical and chemical characteristics of eggshell. The results are as followed:l.The egg loses water continually during incubation, which increases as the time pass. The changes of albumen and yolk weight depend on their water content. There is a phenomenon: albumen water content decreases when yolk water content increases, while yolk water content decreases while albumen water content increases. The water content of embryo see decreasing in the incubation.2.The albumen, yolk and eggshell provide the calcium for the embryo during the different period of the incubation. The albumen accounts for 21.76% calcium provision to embryo development while the shell 78.23%. The yolk plays direct and indirect role in it though the yolk calcium content changes slightly. The yolk can also enrich the calcium.3.The albumen and yolk all provide phosphorus to embryo. 5.98% phosphorus comes from the albumen; the rest are from the yolk. So, the yolk plays a key role inproviding phosphorus. The eggshell does not provide phosphorus for the embryo, while the content increases.4.The embryo absorbs nutrients mainly after the 10th days during the incubation. In the early days, the embryo mainly uses carbohydrate in of the albumen and the yolk. The protein in albumen and fat in yolk is broken down and utilized at the 4th day. The fat content in albumen decreases rapidly after the 10th day. The fat in yolk is utilized faster after the 18th day. With the development of the embryo, the protein content increases while the fat content decreases.5.Amniotic fluid content reaches the peak value at the 16th day, and its PH value stay at 7.0 all the time. Allantoic fluid has the highest content at the 12th day, and its PH value is more than 7.0 all the time, which also achieve the peak value at the 12th day. The PH value of Amniotic and allantoic fluid supplements each other to some degree. Allantoic fluid decreases as the egg-shape index increases, but there is no significant difference (P>0.05).6.The thickness and strength of the eggshell decreases during the incubation. The eggshell thickness is positive correlative with the strength, and the coefficient is 0.357. After incubation, the outer surface becomes more roughly. Awl-shape layer and nipple in inner surface of eggshell disappear, while absorption hole remains.7.The egg weight is positive correlative with the embryo weight and the allantoic fluid, and the coefficient is 0.868 and 0.335 respectively. There is no correlativity between the egg weight and amniotic fluid content. Egg-shape index is positive correlative with the thickness of the eggshell, and the coefficient is 0.30. The correlative coefficient between the egg-shape index and water-losing rate is not significant.