Though the egg-inside-of-an-egg phenomenon is rare, it does happen. It's due to a counter-peristalsis contraction, which happens when an egg is pushed back up into the chicken's reproductive system and becomes embedded in another newly forming egg. It's exactly as strange as it sounds.
B.C. hen lays egg-within-an-egg
The answer is a process known as counter-peristalsis contraction. It occurs when a formed egg begins traveling backwards in a hen's oviduct and becomes embedded inside a second egg in the process of developing. The second egg forms around the first, hence the large size.
When a hen reaches maturity, lighting conditions trigger hormones to start the egg laying cycle. It takes about 25 hours for a hen to create an egg from start to finish. As soon as one egg is laid, the whole process starts all over again and a new egg begins to form.
Finding an egg inside an egg is very rare. Most chicken keepers will never see one, and if they do, they're unlikely to see another again. Eggs inside eggs are like the Halley's comet of chicken keeping. Knight's egg had two anomalies, the rubbery outer egg in addition to the inner egg that formed completely.
The yolk is the source of food for the embryo and contains all the fat in the egg. The small white spot on the yolk is called the germinal disc. The germinal disc is where the female's genetic material is found. When an egg is fertilized the germinal disc divides and develops into an embryo.
Contrary to popular belief, that white thing floating in raw eggs is not a baby chicken's umbilical cord. It's not chicken sperm or a beginning embryo either. (Fun fact: Most commercially produced chicken eggs are unfertilized.) It's a chalaza—pronounced cuh-LAY-zuh—and it's totally normal and safe to eat.
During development, the embryo forms several protective layers around it. As a result, a white colour hard shell is formed around the developing embryo. After this, the hen lays a fertilised egg. The hen then sits on the eggs to provide sufficient warmth to the egg for the development of the embryo into the chicks.
When you crack open the egg, if it's fertile, you'll notice a small white spot on the top of the yolk about 4mm in width. This is called the germinal disc. This is what tells you if the egg has been fertilised. This disc is formed with a single cell from the female and a single sperm from the male.
Your egg will not finish incubating so long as it is cracked. Bacteria will enter through the crack, and the support structure of the shell won't be able to keep the embryo in the correct position. Different aspects of the embryo could get damaged and leak out of the shell as well.
As Science Focus explains, while hatching a supermarket egg is incredibly unlikely, it is possible provided you purchase free-range eggs from the right bird; but if you're concerned about coming face-to-face with a chicken embryo when preparing your standard morning scramble, you can rest easy knowing the odds are in ...
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.
Ovulation (release of the yolk from the ovary) occurs every 24 – 26 hours regardless of fertilization (so a rooster is not needed). A hen ovulates a new yolk after the previous egg was laid. It takes 26 hours for an egg to fully form (white and shell added), so a hen will lay an egg later and later each day.
If the egg is weak, and the shell is thin, she will gobble it up, destroy the evidence and try again. Other times, hens may simply be calcium deficient and are just naturally searching for something to consume that will satisfy this depletion.
A fairy egg forms when a piece of reproductive body tissue or a blood clot separates from the oviduct wall. The hen's egg-producing glands don't know that this tissue is not a yolk, and proceeds to create albumen (egg white), membranes and a shell around it, as it travels through the oviduct.
A man was shocked when he cracked open an egg he'd bought from Woolworths (not to be confused with the late British Woolworths), only to find a dead baby chicken inside. A grim photo of the grey remains was posted on Facebook by Ani Bhowmilk. Ani had purchased the egg in Sydney, Australia.
Canadian farmers discover giant egg with another egg inside and crack it during livestream. A family of farmers in Ontario made an egg-stra special discovery this month after one of their chickens laid a supersized version of the breakfast staple.
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.
If a rooster has mated with a hen, are her eggs always fertile? Not necessarily. Generally speaking, a hen who has mated will be fertile between 7 and 10 days after. It takes that long for the sperm to reach the oviduct where eggs are made.
Typically, you'll see a white circle within the yolk that looks like a bullseye (this is called the blastoderm). It's faded in color and not very large, but if you compare it to an unfertilized egg, you'll get the idea because it will be completely absent from the yolk.
A hen does not know if her eggs are fertilised or not. In fact (much like a human) a rooster can be infertile, so a hen's eggs might not be fertilised even if she is in a flock with a rooster. Many modern breeds and commercial hybrid hens will do nothing with their eggs other than lay them and walk away.
Let stored eggs warm to room temperature for 4 hours to 8 hours before setting them in the incubator. If you place cold eggs in a warm, humid incubator, condensation will form on them and lead to possible contamination or suffocation.
Balut (/bəˈluːt/ bə-LOOT, /ˈbɑːluːt/ BAH-loot; also spelled as balot) is a fertilized developing egg embryo that is boiled or steamed and eaten from the shell.
Birds reproduce by internal fertilization, during which the egg is fertilized inside the female. Like reptiles, birds have cloaca, or a single exit and entrance for sperm, eggs, and waste. The male brings his sperm to the female cloaca. The sperm fertilizes the egg.