Although chickens do not menstruate (and thus their eggs are not “chicken periods” as is sometimes asserted), the cycle of creating and passing much larger eggs relative to their body size and weight is arguably even more physically taxing, especially in modern hens who have been bred to produce such unnaturally high ...
“This claim is completely unscientific and rather bizarre in terms of science”, says Dr Vandana Prasad, a community paediatrician and public health professional. “Firstly, only certain animals, specifically mammals, menstruate and not the poultry.
The incubation period for chicken eggs is 20 to 21 days, and increases up to 30 days for other poultry. After sitting for some days, a broody hen can be given some newly hatched chicks and, if they are accepted, the original eggs can be removed and replaced with more chicks.
On the twentieth day of incubation the embryo becomes a chick as it breaks into the air cell and starts breathing air for the first time. The chick emerges from the egg on the twenty-first day of incubation. Several changes take place during the 18th and 21st days.
Eggs come from chickens and chickens come from eggs: that's the basis of this ancient riddle. But eggs – which are just female sex cells – evolved more than a billion years ago, whereas chickens have been around for just 10,000 years.
It's pretty safe to say that the egg came first, because if there had been no egg, there would have been no chicken. Chickens are birds, and we know that birds evolved from reptiles, so we can say that the first bird hatched from an egg that was laid by a reptile that was very similar to, but not quite, a bird itself.
People have been eating eggs for a very long time— about six million years! The first people to eat eggs took them from nests in the wild and ate the eggs raw. There is no way to know who ate the first egg. What researchers do know is people living in Egypt and China were the first to keep hens.
Most eggs that people eat come from chicken, and chicken are poultry. That said, eggs are an animal byproduct—they're unfertilized eggs from the chicken. Think of them kind of like milk from cows. “So eggs themselves are not actually poultry,” Cording says.
Most eggs sold commercially in the grocery store are from poultry farms and have not been fertilized. In fact, laying hens at most commercial farms have never even seen a rooster. Given the right nutrients, hens will lay eggs with or without having been in the presence of a rooster.
Of course all hens lay eggs, but there are definitely breeds that are better producers than others. While no hen will lay an egg every day, these breeds might come close! Starting around 20-22 weeks old, you should be collecting plenty of eggs from these hens.
If a hen has a dark, comfortable, undisturbed spot where she can nest, she may roll a clutch of eggs (usually 12 to 14) to that spot and begin to brood. You can spot a broody hen by the following behaviors she'll exhibit: She won't leave the nest to roost with the rest of the chickens at night.
When do hens begin to lay eggs? During ideal day length (14-16 hours of light) and with adequate nutrition, housing, and management, hens (depending on breed) should begin producing eggs when they are18- 22 weeks old.
The next question is perhaps, "Why do chickens lay unfertilized eggs at all?" The reason is that the egg is mostly developed before being fertilized. The chicken cannot know in advance whether the egg will end up fertilized or not, so it just has to go ahead and grow the egg in the hopes that it will be fertilized.
It's rare to see as less than 1% of eggs will contain a blood spot. Normally during grading these eggs will be separated, however sometimes an egg will slip through as it's harder to see blood spots in brown eggs. Blood spots are caused by the rupture of a blood vessel during the formation of the egg.
What Causes Blood Spots in Eggs? Blood spots occur when one of those tiny blood vessels is broken during the laying process. The ruptured vessel forms a tiny speck or dot of blood in the egg. Not to worry, blood spots are a natural occurrence when hens lay their eggs.
The cause of a blood spot is simply a ruptured blood vessel on the yolk's surface as the egg is forming. This is a natural, benign process for both hen and egg. Instances of blood spots can increase when hens in a flock get excited by changes in lighting, changes in temperature, or simply shifting seasons.
Did you know you can determine if an egg is fertile or not by looking at the germ spot? The germ spot is the white spot on the yolk. The non-fertile germ spot contains only the female's cells and looks like a solid white spot. In a fertile egg the germ spot contains both the female and male cells.
Fertilization: Sperm Penetrates Egg
It takes about 24 hours for a sperm cell to fertilize an egg. When the sperm penetrates the egg, the surface of the egg changes so that no other sperm can enter.
Does a rooster fertilize every egg? Not always. If a hen is frequently mating with only one rooster, he will fertilize most of her eggs. However, it is still possible that the occasional non-fertile egg will slip through.
This is due to the allergy to ovalbumin, which is the primary protein in all poultry egg whites. Overall, an allergy to the protein found in chicken, or any poultry, is much less common than an allergy to eggs.
Unless they are vegan (meaning they don't eat dairy products, eggs, or any other products which are derived from animals), some vegetarians do eat eggs and belong to a group known as lacto-ovo-vegetarians which according to the Vegetarian Society is the most common type of meatless diet.
Workers needed protein and fat— slow-metabolizing energy sources—to get them through the day, and eggs provided a cheaper alternative to meat.
Why? Because eggs are relatively easy to obtain, excellent protein sources, adaptable to many different types of recipes (from simply boiled, fried, or stuffed to complicated quiche, custards or meringue), and fit the bill for meatless fasting days required by some religions.