# Developing Egg Weights?



## WeeLittleChicken (Aug 31, 2012)

This post is really just about my own nerdy curiosity than anything but here it goes... I know that the embryo in an egg will gain weight over time because it grows, however does the egg itself gain weight? Or does the weight just shift from the egg white and yolk to the embryo? I'm told eggs feel heavier when they are about to hatch but again, this could be just a shift in where the weight is balanced that tricks us into believing that.

I ask because I did a little home study on my Serama eggs and as it turns out they did loose weight when they all died (at day 4 - my stupid incubator spiked - which I didn't figure out until I made the chart.) However this was way too early in the process to know if they would have gained weight if they survived. I did a second round and my incubator did it again. UGH. I am giving up on that thing. Anyway... here's my charts... just wondering if I am wasting my time trying to figure out nothing here.

This first chart is the first batch of eggs I put in there, all at the same time. I gave them each a letter, A-K for identification. Almost all start out at 1oz, going down as far as 0.3oz. Still their trajectory still looks very similar and where the first dip is at, day four does appear to be when they stopped developing (I cracked a couple open after day 23 when I thought it was a safe bet they were definitely dead.) No idea what the second enormous dip is... part of the decaying process? Any idea would be great to hear.










This second chart looks a bit different because I started popping in the eggs whenever they were laid, believing perhaps this was the issue not the incubator. As you can see between October 9th through the eleventh they all seemed to have crashed, which makes sense as my incubator refused to go under 102 degrees at this point no matter how much I turned down the thermostat.  I have yet to crack open egg L to see if it matches the chart as far as development goes. Will do that this evening. Currently I only think there's one egg still viable in this batch, Egg V, as I candled it yesterday. SIGH.










Just for fun this is the only chart that came out right in my mind, probably because I have no real clue how to even make a chart on the computer! Anyway, these are the weights of the two Serama chicks that did miraculously hatch out of the batch prior to the charted eggs.










And finally this is a photo of those two chicks, Mighty and ******, as of yesterday just for fun...


----------



## Energyvet (Jul 25, 2012)

First off, I love the question and the discussion that follows should also prove interesting. As a Veterinarian, I would guess (and that's all it is) is that the weight would decrease initially as nutrient is replaced by fetus. Then I would expect it to continually climb and surpass your initial weight as bone, muscle and body mass fill the space of the egg. I'm also guessing that hydration plays a part as shells are somewhat porus and water and air can move in and out. So intuitively your graph makes sense. But science often has surprises so there may be data that you collect which has not yet been explained. I'm fascinated. Let me know how I can collaborate.


----------



## cogburn (Jul 16, 2012)

Y'all are in way too deep for me, I'm just a simple country boy.. Love the little Seramas !!


----------



## BigECart (Jul 12, 2012)

The mass of the egg will increase/decrease only as moisture is absorbed or released. Per Wikipedia, the law of conservation of mass states that the mass of an isolated system (closed to all transfers of matter and energy) will remain constant over time. I would guess that the reduction in weight of the eggs was due to a loss of moisture within the egg, not due to the chicks dying.


----------



## Willy (Sep 14, 2012)

cogburn said:


> Y'all are in way too deep for me, I'm just a simple country boy.. Love the little Seramas !!


Me too! I'm just keeping 'em warm, turning as needed and hope something hatches.


----------



## WeeLittleChicken (Aug 31, 2012)

EnergyVet: I like your hypothesis. It makes sense, though I guess it remains to be seen if it actually comes out like that. Right now I have one poor laying hen supplying the eggs and an incubator I can't trust at all. It's really quite irksome! However I can tell you what I've done if anyone wants to maybe check it out for themselves with an egg or two... I just labelled the eggs by letter so I could tell them apart, weighed them with a cheap postal scale (which can get to the closest tenth of an ounce) when I collected them and then again every day after that. The data was easy to put into chart form (granted it took a little time typing it in but I don't mind doing it if someone just has raw data to share.) These of course were Serama eggs so they were much tinier than a regular laying hen's! (The only weight chart I could find was Leghorns which wasn't very helpful in both the size aspect and the fact it was just the fetus weights not the whole egg.)

Cogburn: That's OK! Having a wandering mind isn't always a good thing! Thanks for the compliments on the chickies. They're turning out to be sweet little things.

BigECart: I like how you found something to back up your idea! Though I have to wonder if moisture and gases can get in and out is an egg really an isolated system? (I guess that could go either way depending how you look at it...)

Willy: I started out that way...


----------



## Energyvet (Jul 25, 2012)

An egg is an open system if for no other reason because it is a living system and I believe by definition that makes it an open system. The other argument could be that the shell is porus and so things can move in and out. I actually considered if it was possible to take the chick out of the egg and allow it to mature contained in something else. Certainly a plastic bag would not work so I quit thinking about it. Any substitute would be way beyond our little experiment. But a plastic bag would be a closed system albeit with a dead chick inside.


----------



## BigECart (Jul 12, 2012)

I would say that an egg is closer to a closed system than an open one. The egg will absorb air, moisture, and heat, but in general, the developing fetus converts the yolk and whites to flesh and bones. Any measurable additional weight will come from humidity absorbed by the egg. 

As the fetus is absorbing the yolk, it's not a difference of the density of the yolk versus the density of the chick. Instead, the mass of the yolk is converted to the mass of the chick. 

- E


----------



## Energyvet (Jul 25, 2012)

Yes. I agree. The mass of the yolk and the albumen becomes the chick. But I'm thinking bone (even bird bone - meaning hollow) would weigh more than the fluid contents of the infertile egg. I guess that's why we're measuring and discussing this. I don't know the answer. Just speculating here. Just really for fun and information.


----------



## Energyvet (Jul 25, 2012)

So Big E, I guess what you're suggesting is that the increase is mostly due to water increase and that's all. Am I understanding that right?


----------



## MuddyHillFarm (Sep 23, 2012)

*incubation weight loss*

Eggs should lose 11-13 per cent of initial weight during the first 18 days of incubation.

http://www.pasreform.com/academy/fr...al-weight-loss-profile-during-incubation.html


----------



## BigECart (Jul 12, 2012)

Sorry - missed the replies. Whether or not bone weighs more than yolk is immaterial because the yolk is converted into bone with no increase in weight. When women are pregnant, their babies weight increases because of the food and water the mother takes in. 

The last post about eggs losing weight makes sense to me - the egg loses moisture to the air.


----------



## fuzziebutt (Aug 7, 2012)

I'm hearing the voices now...


----------



## WeeLittleChicken (Aug 31, 2012)

MuddyHillFarm said:


> Eggs should lose 11-13 per cent of initial weight during the first 18 days of incubation.


Hmmm.... the only problem I have with this is the fact that the eggs I have been weighing all loose this amount of weight regardless if they are developing or dead.... 

Other than that very cool article. Thanks!


----------

