Double yolk egg refers to an egg with two yolks in an eggshell, which is usually much larger than ordinary eggs. Double yellow eggs are formed because two eggs mature at the same time and are separated from follicles and brought into fallopian tube, where they are wrapped by protein, shell membrane and eggshell in turn. Sometimes even multiple eggs mature at the same time and are brought into the fallopian tube together, thus becoming multi-yellow eggs.
This is similar to the formation process of human fraternal twins, but there are essential differences. Dizygotic twins are two eggs released by women during ovulation and fertilized at the same time, resulting in two different fertilized eggs, which eventually develop into twins. But the egg cells in the double yellow eggs are not fertilized, so they can't hatch into chickens.
The production of double yellow eggs by poultry is often related to the richness of food and the health of poultry. Double yellow eggs contain two yolks, which are rich in nutrition and are deeply loved by the masses. Now people have begun to cultivate double yellow eggs artificially, and some manufacturers specialize in selling double yellow eggs.
It is very common to lay double yellow eggs. A hen sometimes lays several double yellow eggs in the same nest, but usually only a few hens in the flock can lay double yellow eggs.
Three yellow eggs are rare. The reason for this abnormal egg is the abnormal timing function of the ovary (normally, a yolk is released from the ovary every 26 hours).
A hen ovulates two or more eggs at a time or matures too early. After ovulation, they meet in the fallopian tube and are wrapped by protein, forming double yellow eggs or triple yellow eggs.
The rate of double yellow eggs laid by primiparous hens is higher than that of old hens. This is because primiparous hens have strong physique, strong vitality and strong ovulation ability. Premature chicks are also prone to lay a lot of yellow eggs, because the sex organs of chicks are not fully developed and mature, and they cannot completely control normal ovulation.
However, some people think that double yellow eggs are produced by hens due to physiological reasons such as endocrine disorders, and it is best not to eat too much, but natural double yellow eggs are still rare.