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I was hoping some of the more observant members can help me out identifying the visual stages in eggs from newly lain to fertile.

 

I'll start it off -

 

1. A newly lain egg is clear with a discernible air bubble at one end

 

2. Once the hen starts incubating .....

 

How many hours until changes can be observed?

What are those changes?

How long till you see the beating heart?

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You sit next to those eggs and check with a stop watch and notebook........too flippin hard for me :blink::D

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I'm not that observant. My time on checking is about 5 secs an egg. For me it's clear, fertile or addled. Thats all I look for. ;)

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Me too, but I have noticed on the third day after the hen starts sitting I can tell the egg is fertile but other than that I just leave them be. Check morning and night.

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okay, let's approach this a different way. smile.gif

 

 

 

What do infertile eggs look like?

For example, Yellow eggs where the yolk sac looks like it has dispersed throughout the egg?

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Look the same as fertile eggs at first but show no blood vessel development after several days of incubation. After a while a fertile egg will look darker sort of and an infertile egg will still look freshly laid. Addled eggs often get dark and discoloured. I think there are several threads that will give you this sort of info.

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Look the same as fertile eggs at first but show no blood vessel development after several days of incubation. After a while a fertile egg will look darker sort of and an infertile egg will still look freshly laid. Addled eggs often get dark and discoloured. I think there are several threads that will give you this sort of info.

 

Thank you nubbly smile.gif

 

Yes, I have had a search but couldn't find exactly what I am looking for (ie. stages of pre-fertility)

 

For example, Yellow eggs where the yolk sac looks like it has dispersed throughout the egg?

 

 

Well I've had a little think and so to answer my own question I would venture that seeing as the yolk sac feeds the soon-to-be-hatched-chick Then if it has dispersed throughout the egg it must make it an INFERTILE egg. rolleyes.gif

Edited by renee

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Actually if you really look there is a change in the shell within 24 hours.

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Actually if you really look there is a change in the shell within 24 hours.

 

Aha! wink.gif

 

 

Thank you RIP for confirming that there are changes. Please be kind and describe what you have observed. smile.gif

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I was hoping some of the more observant members can help me out identifying the visual stages in eggs from newly lain to fertile.

 

I'll start it off -

 

1. A newly lain egg is clear with a discernible air bubble at one end

 

2. Once the hen starts incubating .....

 

How many hours until changes can be observed?

What are those changes?

How long till you see the beating heart?

These pictures might help.

P1030821.jpg

P1030818.jpg

P1030822.jpg

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Thank You PJI for taking such excellent photos of fertile eggs in the early stages of their development. smile.gif

 

 

 

I am however, trying to find out what the earlier stages before veins are visible with candling look like.

 

If anyone knows what actually happens (ie from an academic point of view) at the start of incubation, that would be good too.

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This doesn't help tell what the egg looks like, but it tells about how the chick develops, and was interesting. http://msucares.com/...cks_embryo.html

 

I'm going back to look at several other interesting-looking links that came up in my Google search. :)

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Thank You Finnie for a brilliant article smile.gif

 

Here it is in full -

 

Stages in chick embryo development

 

One of the greatest miracles of nature is the transformation of the egg into the chick. A chick emerges after a brief three weeks of incubation. The complexity of the development cannot be understood without training in embryology.

 

embryo1.jpg

 

When the egg is laid, some embryonic development has occurred and usually stops until proper cell environmental conditions are established for incubation to resume. At first, all the cells are alike, but as the embryo develops, cell differences are observed. Some cells may become vital organs; others become a wing or leg.

 

Soon after incubation begins, a pointed thickened layer of cells becomes visible in the caudal or tail end of the embryo. This pointed area is the primitive streak, and is the longitudinal axis of the embryo. From the primitive streak, the head and backbone of the embryo develop. A precursor of the digestive tract forms; blood islands appear and will develop later into the vascular or blood system; and the eye begins.

 

On the second day of incubation, the blood islands begin linking and form a vascular system, while the heart is being formed elsewhere. By the 44th hour of incubation, the heart and vascular systems join, and the heart begins beating. Two distinct circulatory systems are established, an embryonic system for the embryo and a vitelline system extending into the egg.

 

At the end of the third day of incubation, the beak begins developing and limb buds for the wings and legs are seen. Torsion and flexion continue through the fourth day. The chick's entire body turns 90o and lies down with its left side on the yolk. The head and tail come close together so the embryo forms a "C" shape. The mouth, tongue, and nasal pits develop as parts of the digestive and respiratory systems. The heart continues to enlarge even though it has not been enclosed within the body. It is seen beating if the egg is opened carefully. The other internal organs continue to develop. By the end of the fourth day of incubation, the embryo has all organs needed to sustain life after hatching, and most of the embryo's parts can be identified. The chick embryo cannot, however, be distinguished from that of mammals.

 

embryo2.jpg

 

The embryo grows and develops rapidly. By the seventh day, digits appear on the wings and feet, the heart is completely enclosed in the thoracic cavity, and the embryo looks more like a bird. After the tenth day of incubation, feathers and feather tracts are visible, and the beak hardens. On the fourteenth day, the claws are forming and the embryo is moving into position for hatching. After twenty days, the chick is in the hatching position, the beak has pierced the air cell, and pulmonary respiration has begun.

 

After 21 days of incubation, the chick finally begins its escape from the shell. The chick begins by pushing its beak through the air cell. The allantois, which has served as its lungs, begins to dry up as the chick uses its own lungs. The chick continues to push its head outward. The sharp ***** structure on the upper beak (egg tooth) and the muscle on the back of the neck help cut the shell. The chick rests, changes position, and keeps cutting until its head falls free of the opened shell. It then kicks free of the bottom portion of the shell. The chick is exhausted and rests while the navel openings heal and its down dries. Gradually, it regains strength and walks. The incubation and hatching is complete. The ***** cap will fall off the beak within days after the chick hatches.

 

 

 

EVENTS IN EMBRYONIC DEVELOPMENT

 

Before Egg Laying:Fertilization

Division and growth of living cells

Segregation of cells into groups of special function (tissues)

 

Between Laying and IncubationNo growth; stage of inactive embryonic life

 

During Incubation:

 

First day16 hours - first sign of resemblance to a chick embryo

18 hours - appearance of alimentary tract

20 hours - appearance of vertebral column

21 hours - beginning of nervous system

22 hours - beginning of head

24 hours - beginning of eye

 

Second day25 hours - beginning of heart

35 hours - beginning of ear

42 hours - heart beats

 

Third day60 hours - beginning of nose

62 hours - beginning of legs

64 hours - beginning of wings

 

Fourth day - beginning of tongue

 

Fifth day - formation of reproductive organs and differentiation of sex

 

Sixth day - beginning of beak

 

Eighth day - beginning of feathers

 

Tenth day - beginning of hardening of beak

 

Thirteenth day - appearance of scales and claws

 

Fourteenth day - embryo gets into position suitable for breaking shell

 

Sixteenth day - scales, claws and beak becoming firm and *****

 

Seventeenth day - beak turns toward air cell

 

Nineteenth day - yolk sac begins to enter body cavity

 

Twentieth day - yolk sac completely drawn into body cavity; embryo occupies practically all the space within the egg except the air cell

 

Twenty-first day - hatching of chick

 

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okay I get dissed on every time I say when the third egg is laid the first is fertile.

Day 1 , Egg 1 laid.

Day 2 , No visual change.24 hours

Day 3 , Egg 2 laid, At times Here I have found in egg 1 a change in yolk colour ( Richer or Intenser) 48 hours

Day 4, Egg1 Definate visual change in Yolk colour in Egg 1 , Egg 2 no visual change.72 hours

Day 5 Egg 3 laid, Egg 1 shows Definate Veins and Fertility, Egg 2 Look for yolk colour change . 96 hours.

And so on.

Now the disclaimer!!., So you can leave out the negative posts. Your Hen must be a Hen that Sits upon laying. First Lesson for all Novice breeders, For me if a hen isnt sitting she is a Young hen and forget all the above, she has to be trial bred. Or your Hen isnt in full condition and may cause problems so prepare yourself. I have just finished my 11th breeding year in Exibition Budgerigars.

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I have noticed the same as Matt, If the hen sits straight.

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