Where Do Eggs Come From? What's All About Hens And Their Eggs? | Kidadl


Where Do Eggs Come From? What's All About Hens And Their Eggs?

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The photo-receptive gland close to a hen's eyes is stimulated by natural sunlight or artificial light in a commercial egg hatchery which signals the releasing of an egg cell from the hen's ovary.

One can say eggs are most famously used around the world for delicious foods. However, we lack complete knowledge about the process of producing an egg.

One of the first birds to be domesticated for eggs were chickens in India and Southeast Asia, earlier than 7500 BCE. By 1500 BCE, chickens were brought to Egypt and Sumer, and by 800 BCE brought to Greece. These eggs reached Europe and West Asia. Before chicken eggs got common, geese and ducks were also used for eggs and people did not have to go hunting for eggs anymore. Eggs contain a lot of nutrients and protein. Chicken farmers from China and Egypt, in around 300 BC, found a way for incubating the eggs in a warm clay oven instead of letting chickens incubate eggs. This was done to allow hens to lay more and more eggs. This made eggs cheaper, allowing more people to buy them. Did you know that the egg-laying process starts in the hen's eyes? You read that right; hens depend on light cues, either natural or artificial, to lay eggs. Hens can produce eggs that have two or sometimes three yolks and some are even yolkless!

Like female humans, hens ovulate. Hens produce large eggs compared to their weight and size which makes the process physically tiring. This is even more tiring for modern-day hens that have been bred to produce an unnaturally high number of eggs. All through the Modern Age until now, eggs were laid only during the spring seasons in a year when there was a lot of natural daylight. This is also the reason behind Easter eggs as they traditionally celebrated the return of eggs. Previously, fresh eggs would be good for only about a few weeks or a month but now, some eggs are pickled by farmers in vinegar and salt for them to keep them fresh and give them a longer shelf-life. Also, chickens or poultry nowadays lay eggs year-round due to the unnatural processes used on an egg production farm. Let's look at some more answers.

If you enjoyed reading these facts that answer where do eggs come from, then make sure to read some more interesting facts that answer questions such as where do beans come from and where do bay leaves come from here at Kidadl.

Where do chicken eggs come from?

Eggs come from different breeds of chickens in different production systems.

Chickens are capable of laying eggs without a rooster and hens are raised to produces unfertilized eggs. So, in egg production farms, hens need around 24-26 hours to produce an egg. After an egg has been laid, the chickens lay their next eggs after 30 minutes. Chickens lay fertilized eggs in the presence of one rooster raised in poultry farms. As a chicken is photo-receptive, not all farms use artificial lighting for egg production, some of them use natural lighting systems.

The systems for producing eggs can also be different, with pros and cons to each. These methods include barn laid, free-range, and cage-free eggs. The barn-laid and the cage-free system have these animals housed inside a barn environment. In contrast, the free-range method provides access to outdoor range in the day, and then the hens are secured in sheds at night. Hens in commercial farms lay fine quality eggs until they turn one and a half years old, after which shells are more prone to breaking and they produce fewer eggs overall. Eggs are released from a checked butt, which is through a separate tract for only eggs and not through their digestive tract. Also, when hens lay eggs their intestine is closed. After a certain number of eggs are laid, hens go into a stage called 'brooding'. This is a maternal stage, so the mother sits on (or incubates) the eggs until they are ready to hatch. To prevent this, eggs must be removed every day. Hybrid chickens that are bred especially for laying eggs every day live only for a couple of years and the everyday egg-laying process can be deadly for hens.

Hens always suffer due to unnatural overproduction of eggs and at around two years of age, they reach slaughterhouses with painful breaks on their legs and wings. Some of the diseases caused by this system of egg production are egg binding, uterine prolapse, peritonitis, and oviduct tumors.

Basket of chicken eggs on a wooden table.

Where do brown eggs come from?

Brown eggs come from the same hen that produces white eggs.

It has long been believed that brown eggs are more natural or healthier and others think that white eggs taste better and are cleaner. You can find various colored eggs in a grocery store Most hens lay only one colored egg for life. The color also depends on the breed of chicken. For example, Rhode Island Reds and Plymouth Rocks hens lay brown eggs, and White Leghorn hens lay white colored eggs. Blue-green or blue eggs are produced by the Dongxiang, Araucana, Lushi, and Ameraucana hen. Not only do genetics play a role in producing different-colored eggs but also the age, environment, and breed of hen contribute as well. Regardless of the color, grade, and size, all eggs have a similar nutritional value.

Scientists studied both white and brown colored eggs, and the results showed no difference in composition and quality. The nutritional value altered due to the environment; hens that were allowed to roam in sun produced eggs with more vitamin D than the ones from caged hens. Differences in feed can also impact the nutritional value. Some people state that brown eggs are way better in taste than white ones. However, the color of an egg does not decide its taste. Also, not all eggs taste the same. The taste of eggs from commercial farms varies from the home-raised eggs due to differences in diet. If the eggs are stored properly, this preserves the taste. Brown eggs cost more than the white ones in stores due to this belief.

So, there is no nutritional difference between a white egg and a brown one. Varieties of eggs include organic, omega-3 enriched, backyard and local, cage-free, and free-range.

In how many days do chicken eggs develop?

The process of laying an egg takes around 24 hours to be completed. The egg-laying hens also need 14 hours of sunlight or artificial lighting on a farm.

The main parts of an egg are the shell, yolk, chalaza, albumen, and shell membranes. Egg yolks are the most obvious part and yolks are situated near the center of the egg. Egg white is called the albumen. This part is named because when cooked, it turns white. There are two layers in the albumen, a thin one and a thick one closer to the yolk. Within the albumen lies chalaza, which is nothing but tightly twisted albumen. Chalaza prevents egg yolks from sticking onto the shell walls. The thin outer and inner shell membranes hold the egg contents. Lastly, the shells hold everything together. There are thousands of tiny ova present in a laying hens' ovary in the reproductive tract. Among all the egg-laying animals, birds are unique as only one of their ovaries matures to produce eggs. The yolk moves into the oviduct from the ovary once it is ready. The oviduct is a tube-like framework, which divides into four sections.

The yolk goes into a part called the magnum, which is present in the oviduct and the egg protein is added to the yolk. The egg white has a lot of proteins, which protect the yolk and build patterns for the shell and shell membranes' formation. Then, the egg moves through to a part called the isthmus, a place that produces shell membrane fibers. After this, the egg moves into the shell gland and over approximately 20 hours, a shell is formed. This development is called calcification as the shell is formed by calcium carbonate layers. The pigment bulk, either brown or white is produced and it accumulates on the outer shell in the last two hours before the laying of the egg. However, a chicken might lay one colored egg in her life. A cuticle is also laid on the shell which protects the egg against foreign material that might enter the shell and prevents water loss. Even though the egg moves the small end first through the oviduct, it rotates before laying and comes out large end first. Many breeds of chickens usually lay eggs from around four months of age (16-18 weeks).

What are the major health benefits of eggs?

Eggs are one the most nutritious food sources containing vitamins, healthy fats, protein, zinc, calcium, and phosphorus.

As soon as chickens were domesticated people started eating eggs. We must be thankful to chickens for providing this food that we have been eating for so long. Eggs belong to one of the most nutritious food groups. Eggs have vitamins, healthy fats, protein, zinc, calcium, and phosphorus. Although eggs have high cholesterol, they would not necessarily cause cholesterol to rise in the blood. In a study, about 70% of egg consumers their cholesterol did not vary and in the remaining 30%, the LDL and total cholesterol mildly increased. Eggs also increase good cholesterol, increasing immunity against diseases. A nutrient called choline, which is grouped with B vitamins and is very important, is also found in eggs. There is more than 0.003 oz (100 mg) of choline in one single egg. Eggs reduce the risk of a heart attack and there are antioxidants called zeaxanthin and lutein that are found in high quantities in eggs, which improve eyesight. Eggs reduce blood triglycerides and are a high source of quality protein and amino acids. Many studies show that eggs are not a related cause of heart attack or stroke. Eating eggs is quite filling and allows you to consume fewer calories making you feel more satiated.

Here at Kidadl, we have carefully created lots of interesting family-friendly facts for everyone to enjoy! If you liked our suggestion for where do eggs come from, what's all about hens and their eggs, then why not take a look at why do cats sleep on you, know your cat's sleeping habits, or when do women stop growing, curious body growth facts to know?

<p>With a background in Aeronautical Engineering and practical experience in various technical areas, Arpitha is a valuable member of the Kidadl content writing team. She did her Bachelor's degree in Engineering, specializing in Aeronautical Engineering, at Nitte Meenakshi Institute of Technology in 2020. Arpitha has honed her skills through her work with leading companies in Bangalore, where she contributed to several noteworthy projects, including the development of high-performance aircraft using morphing technology and the analysis of crack propagation using Abaqus XFEM.</p>

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