Chicken is the most popular bird in peasant farms and farms. The breeding of this bird allows to solve two problems at once: the provision of meat and eggs. So for the owner it is important to know how to distinguish the fertilized eggs from unfertilized.
And devices that can help in the checking of eggs.

For this purpose there is a special machine produced by the domestic industry – candling. It is a small container with grooves for laying eggs and illumination located on the bottom. If such a device is not in the household, you can substitute homemade or use a regular piece of thin cardboard rolled into a tube with a thickness of 2-3 cm One end of it to attach to the egg, podnebennoy the light source and from the second to examine its contents.
How to know whether a fertilized egg?

If the egg embryo, it's possible to determine no earlier than 6 days after the start of incubation. When scanning in the early period (4-5 days) may be visible shaded area without clear boundaries the size of a match head, which, when turning the eggs horizontally moves after yolk, a little behind him by the speed of rotation. Poultry farmers claim that if this area looks like the letter "O", that is, the more pronounced the contour of the spot, then the egg is fertilized. If the stain darkened completely, no.
On the 6-7 day in the thinner end of the egg becomes clearly noticeable by a network of delicate blood vessels located near the yolk clearly visible air chamber. Germinal disk (blastoderm) reaches a size of 5-8 mm, it becomes more clear shape and still looks like a pretty dark spot. If blood blotches scattered in the content, it is a sign that the embryo is not there, or he died. Consider eggs pointy end down, slowly turning them clockwise.
In 7-10 days it is possible to determine reliably whether the chick is alive. If he properly develops, the yolk becomes more pale. In the result of embryonic activity is the exchange and around the embryo is formed a light yellow ring. He looks like a dark spot of irregular shape with distinct boundaries. On day 18 using the medical stethoscope to hear the fetal heartbeat.