What is the fertilization process for chicken eggs?

Answer 1

The male mounts the hen from behind and stands on her back. The rooster's cloaca transfers semen into the cloaca of the hen. The cloaca is a common receptacle for the intestinal tract, the reproductive system and the urinary system. A spermatozoa sac makes its way up the oviduct and is stored in accessory sex organ in the female. There, the sperm is nourished and released over several days. So the rooster does not have to mate with the hen each time she lays an egg to produce a fertile egg. Fertility only remains high for about 10 days before another mating is needed to increase fertility of the eggs laid. Egg yolks that have a germ cell on the surface are ovulated about every 24 to 26 hours. The spermatozoa fertilize the germ cell, then the albumen, or white of the egg is secreted around the yolk by the reproductive tract. Then the shell membranes and the shell are secreted and deposited as the egg travels down the reproductive tract. The egg is laid back through the cloaca, as mentioned above. This is the way fertile eggs are laid by the hen. The hen would still lay eggs if a rooster were not around, but the eggs would not be fertile.

Answer 2

I think the egg is fertilized before it fully becomes an egg with a shell, as we know it. The rooster mates with the chicken and when the chicken ovulates, the sperm fertilizes the egg, begining the process to form (cells divide and develop) -- as the egg with shell is released from the chicken's body to be incubated. 21 days later a chick is hatched.

Answer 3

Prior to being laid, a fertilized chicken egg will have already gone through some small changes that usually stop until correct environmental conditions restart the growth stage.

Very shortly after incubation begins, a thick layer of cells forms in the caudal end (tail) of the embryo. This is called the primitive streak and is the axis on which the chick will form. This takes about 12 hours in optimum conditions. At the same time the head, backbone and eyes of the chick will form. Within 36 hours blood islands begin to develop and form a vascular system along with heart and digestive system beginning. At the end of 48 hours the beak, and limb buds have formed. The embryo will at this point turn 90 degrees and rest on the yolk on its left side curling up to form a "C" shape with head almost touching the tail area. The forming bird will have all the organs it needs to live, started and developing.

By the end of the first week, wing tips and feet have formed and the heart is beating.

By the second week rudimentary feathers have formed and the chick is putting growth effort into size and strength. On day 20, the chick will move into hatch position and begin opening the inner membrane with its "egg tooth" located on the upper end of its beak.

It will emerge from the shell on day 21.