What's with the hen crowing at home?

This may be due to irregular light irradiation, which makes estrogen secretion abnormal, so it rarely happens.

It may also be that hens usually eat too much androgen in the feed and are exposed to irregular light, which leads to the atrophy and degeneration of hen ovaries, which leads to such strange things. If the damage to the hen's ovary is not too great, it will turn back into a hen after a while. If it hurts too much, it will become a strange look that is neither a rooster nor a hen, and it will never become a rooster completely.

As early as in ancient Shang Zhouwang, there was a phenomenon that hens turned into cocks among the people. We use the idiom "selling chicken Chen Si" to describe it. Pin refers to women. This idiom describes the phenomenon that hens begin to crow in the morning. At that time, because of the phenomenon of hen sex reversal, various governors decided that this was da ji's insurrection, which was an ominous sign. Zhou Wuwang marched eastward and replaced Shang and Zhou Dynasties.

These are true historical stories. In nature, how is the sex of higher animals determined? Usually, the sex of higher animals is determined by sex chromosomes, and different sex chromosome compositions often determine the sex characteristics of biological individuals. For example, the sex chromosome composition of men in human beings is XY, and there are key genes on the Y chromosome that determine the development of male reproductive system, so it can promote the development of male reproductive system, produce a large number of male hormones, and further show male gender characteristics, such as long beard and Adam's apple. Women are XX. Without this key gene, they will develop into girls. But in some insects and birds, the decisive sex is ZW chromosome, that is, ZZ (homotype) in males and ZW (heterotype) in females. Can you see the difference between these two sex decisions? There are differences because of different sex chromosome compositions. For example, a rooster can crow, with a comb and gorgeous tail feathers, while a hen does not have these characteristics, but can lay eggs.

The sex of birds is initially determined by sex chromosomes, but sex differentiation is controlled by sex hormones in the incubation stage. Under normal circumstances, the female gonads of ZW embryos develop first, secrete hormones, promote the development of female characteristics, and inhibit the development of male gonads (Figure 3); ZZ embryos have no estrogen, so they will give priority to the development of male reproductive system. Therefore, if chicken embryos are treated with estrogen at the initial stage of incubation, it can lead to different degrees of female development of male embryos.

The phenomenon that male or female individuals become heterosexual individuals is called "gender inversion". There are many reasons for sex reversal, such as animal's physiological state, external environment, hormone treatment and so on. So the explanation of "Hen's Morning" is: because the female bird is asymmetrical in the development of reproductive system. The left gonad develops into functional ovary and fallopian tube, while the right gonad remains in its original state to maintain its weight and facilitate flight. Because adult hens only have the left ovarian fallopian tube to develop, once they are damaged by external stimuli, they can no longer produce enough hormones. At this time, the undifferentiated primordia of the reproductive system on the right side are no longer inhibited by hormones, and then develop into testicles, and hens become fertile cocks, resulting in the situation of "treating chickens for the morning".

However, in nature, roosters rarely have sexual inversion, because in males, gonads develop into symmetrical bilateral reproductive systems. Therefore, if the cock's reproductive system is damaged by external stimulation, it will only lead to the failure to maintain the male's sexual characteristics and form the female's reproductive system, so there is no "laying cock" in nature.