According to foreign media reports, when people eat eggs, they often wonder: will a chicken come out after the eggs are broken? You may never have encountered such a situation, but does it exist? We’ve all tried at least once, trying to hatch eggs we bought through heat preservation, but almost all commercially available eggs are unfertilized! This means that there are no developed chick embryos in the eggs we eat. Here are the explanations: < / P > < p > chicken embryo life begins even before the hen lays eggs. There are embryos of different sizes and maturity in the ovaries of hens, and only the left ovary of hens (all other female birds) has fertilization function. < / P > < p > the oocytes released from the left ovary may fertilize the male’s sperm, which usually occurs about 24 hours before laying eggs. If there is sperm from the cock, the sperm and the yolk cells of the hen fuse together to form an embryo. Before laying the egg, a hard shell will be formed on the yolk, which is the eggshell we see. < / P > < p > hens don’t know whether the eggs are fertilized, so they have to hatch all the eggs. They will sit on the eggs day and night, hoping to hatch chickens. These hens are called “brooding hens,” and they are very focused and only responsible for hatching eggs every day. What’s interesting is that eggs can be laid without Rooster fertilization! Every 24-27 hours, a “laying hen” in a poultry farm lays an egg. All they need is the right nutrition, namely calcium and vitamin D3, and proper physical conditions. Light stimulates the laying process, and some farms even use artificial lighting to regulate the laying process in winter. < / P > < p > although there is no difference in nutritional composition and taste between fertilized and unfertilized eggs, most commercial farms still prefer to keep hens only in the henhouse, because one Rooster can mate with 10-12 hens, and if not properly controlled, the number of chickens will soon be out of control! < / P > < p > in the wild, the hen lays eggs every day until the number reaches more than ten, and then she sits on a nest of eggs to hatch day and night. The number of eggs to be hatched “varies from bird to bird”. Usually, a chicken hatches about 12 eggs in a litter, and then rarely lays eggs in a short period of time. In the cold winter, especially in the few months when food is scarce, hens will stop laying eggs because it is difficult to raise offspring in bad weather conditions, and the shortening of sunshine time also prevents laying eggs. These factors reduce the number of eggs laid by wild hens, so they usually lay eggs only in spring. Red pheasants lay only 10-15 eggs a year. It is worth noting that most of these eggs will be fertilized. Because it is almost always possible to find cocks and hens together in the wild, most eggs hatch into chicks in about 21 days. By contrast, “laying hens” can lay 300 unfertilized eggs a year. However, is the process of producing unfertilized eggs futile? Natural selection is considered to be beneficial to reproductive health, which means that the evolutionary principle of “survival of the fittest” ensures the survival of species with high reproductive success rate. A basket of unfertilized eggs can not prove “reproductive success”. So how can hens survive in natural selection? < / P > < p > it turns out that humans have been choosing hens that can produce more eggs, which is known as “selective breeding”, “evolution caused by human manipulation”, or “artificial selection”. Through selective reproduction, human beings only select individuals with dominant characteristics in a certain species to mate, thus strengthening these characteristics of offspring. This is due to gene mutation induced by human induced selective pressure. Through long-term improvement of laying hens, the consistency and peak yield of laying hens can be ensured. On the other hand, artificially selected broilers are improved to eat meat, and their meat quality is very good. In contrast, laying hens have almost no meat. They concentrate all their energy and nutrition on laying an egg every day. This shows how human beings choose characteristics artificially to optimize different breeds of chickens, so as to achieve different purposes. The difference in the number of eggs laid by field hens and farm hens was related to the daily collection of eggs by the breeders, which prevented the hens from hatching, so they continued to lay one egg a day. Another reason is that over the past few years, humans have made slow improvements to hens to prevent them from laying eggs in the winter. Artificial light sources are still used in poultry farms to keep laying eggs in winter, although some traditional breeds are “out of production” in winter. < / P > < p > all of the above causes the laying hens to produce a large number of eggs, and at the same time, the farms deliberately separate the cocks from the hens, which is the main reason for unfertilized eggs. < / P > < p > if you want to know if a freshly broken egg is fertilized, observe for a small white spot on the yellow yolk for the next 24 hours, and if so, notice the formation of blood vessels around the comma shaped chick embryo. < / P > < p > nevertheless, microvessels and blood spots do not represent embryos. Blood spots may be caused by vascular rupture, which may occur in any part of the reproductive system and may lack vitamin A. < / P > < p > is it possible for a fertilized egg to appear in more than a dozen eggs you buy? Even if we take into account the small probability that fertilized eggs may be sold, it is impossible for us to eat developing chicken embryos, because all commercially available eggs are refrigerated prior to sale, which prevents the development of chick embryos. < / P > < p > in addition, food safety measures require that the inside of eggs to be sold be inspected, which is achieved through a process called “shining eggs”, in which bright light continuously shines on the surface of the eggshell, and any abnormal phenomenon can be detected by illuminating the egg, including the developing chicken. As a result, it is impossible for people to eat chick embryos in development. They can enjoy a healthy breakfast every morning, and remember to eat an egg to maintain daily nutrition intake. (Ye Qingcheng)= target=_ blank>Global Tech