Embryology opinions...

[ShreddedOakAviary]

I was recently asked to try and incubate some greenwing macaw eggs that came from a hen that always lay infertile eggs. I tols them they were probably infertile again but that I would incubate them, abd if/when they were confirmed clear I would do what I always do with parrot eggs that fail to hatch... crack them open and take a closer look. Here is what I found...

Egg1... shell was thin, yolk membrane was the weakest of I've ever seen. Now for the weird part.... 4 blastodiscs were found on the yolk... never seen that before.

Egg2... even thinner shell, and the entire shell was was like a sort of sponge... full of tiny holes in the shell (not the membrane), now I know even if this egg had been fertile, it would have gotten an infectiin and died.

Here's what I know about the hen for sure... she has had 2 different mates (they kept thinking it was the males fault), she has been owned by the same guy for over 6a years and not produced a fertile egg. She has been thoroughly vetted 3 times to rule out infection or illness as the cause. She's had 4 panels of blood work sent to the lab over that time period to again check for illness, metal toxicity, herpes, etc...

I posted about thia on my facebook and tagged Rick Jordan to see what he thinks, but I am wondering if anyone here has seen such a thing. Just a shot in the dark. Thanks in advance...

Post script...

They say the hen is under 20 years old, but it cannot be confirmed, and based on other signs I'd guess her mucg older. However since the most common reason for an old hen to fail as a breeder is lack of folicles, and she is still laying eggs with multiple blastodiscs, we can rule out a follicular count issue out. So, now what?

 

[sssaucey]

I don't know much about this kind of thing ,but it sounds like her body has trouble making the shell. Since the shells are to thin or to porous maybe she's to old to take in enough calcium for the eggs and herself?

 

[ShreddedOakAviary]

Striations in the eggs supports the theory that the hen is calcium deficient for some reason. Ill ask about age being a contributing factor.

 

[sssaucey]

Has she ever produced a fertile egg? I know you said the current owner has had her for 6 years. Maybe it's something she was born with?

 

[ShreddedOakAviary]

I wonder if severe inbreeding (not sure if she's inbred, but it's a possibility) could cause certain reproductive tract deformitie.

 

[ShreddedOakAviary]

Or maybe just a freak development problem while she herself was in an egg. I am just trying to see if there is a more concrete confirmable answer. She has been surgically sexed by Scott and nothing looked amiss.

 

[cdog]

I'm no expert but I would say severe inbreeding to the point that she cant hold calcium or produce enough calcium. I would think its like dogs, they want the dogs bloodlines to be pure bred so they breed with other pure breds which eventually overlap each other and soon they are breeding with siblings or parents. I assume they would do the same for birds but that's just a guess.

 

[ShreddedOakAviary]

Has she ever produced a fertile egg? I know you said the current owner has had her for 6 years. Maybe it's something she was born with?

I don't know. I asked, but the owner doesn't know either.

 

[sssaucey]

I'm sure if she was inbred it could have some ill effects, can they check for things like that in birds?

Hopefully what ever is causing this will not harm her in anyway, it's weird that they haven't found a definitive answer yet

 

[ShreddedOakAviary]

I still err on the side of nore than just egg shell development problems, to have 4 blastodiscs in a single egg seems to point to another reproductive track problem or deformity. So now we have agreed that something is likely physically wrong with either her hormones, reproductive tract, or (most likely) both.

 

[sssaucey]

Since the shells are so thin will he have to watch out for eggs breaking inside her?

 

[lene1949]

Now for the weird part.... 4 blastodiscs were found on the yolk... never seen that before.

I did google it, but I just wondered if you can explain it in words I can understand? and what did you do to find that?

 

[ShreddedOakAviary]

The blastodisc is the hens half of the genetic material. In a fertile egg it is called a blastogerm. Or germinal disc. Anyway, as a fertile egg develops inside the hen, the blastogerm (in a fertile egg) has already started growing. If you crack open a store bought egg, you could roll the yolk until you see a tiny irregular spot with a clear ring around it. Anyway, basically I cracked the egg open because even if an egg died the second it left the hen, the blastodisc/blastogerm are VERY different between fertile and infertile. To have 4 in an egg is simply weird.

 

[henpecked]

Doesn't Vit D,D3 deficiency inhibit calcium absorption ? Lack of sunlight and a seed diet. You can get drops to add to their water at the local GNC. Vit A is also necessary for reproduction and is something i'd check for. I wouldn't find multiple blastodisc usual if egg shell production was inhibited, putting all her eggs in one basket ,so to speak. I'm no expert ,just taking a guess.

On a tangent, had two hen zons,one laid 6 fertile eggs ever year in 2 clutchs. The other laid 6 eggs a year but only one was fertile.Same thing every year. So i switched males,everything worked out and every body was happy and started laying again.Same situation the same hen only had one fertile egg a year and the other had 6, guess it wasn't the male's fault after all.Go figure.my wife told me everything was always the males fault,LOL.

 

[merlinsmom13]

Very interesting thread. I had a rhode island red hen who laid only double yolked eggs, something genetic that caused this?

 

[ShreddedOakAviary]

She has always been on a good diet, d3 and calcium should be fine. I'll double check with owner. Though I had forgotten that if she is getting too much vit A that it can inhibit the absorbtion of calcium... so I'll double check the ingredients in his fresh food mix.