Genetic faults and vaulted skulls

[Kamivy]

Hi guys,I have just had a couple of batches of my own fertile eggs hatch out, and I think I have some problems. I set 36 eggs, only 20 made it to lockdown, and then thanks to a bad temp spike during lockdown only 6 hatched. I then had to cull 3 due to neurological symptoms, including ataxia, seizures and a paralysed leg. I put this down to damage from the temp spike. I also discovered about 50 % have vaulted skulls. These are Australian araucanas, so should not have vaulted skulls! I'm not sure if this indicates possible breed contamination (i.e polish) or if it's a sign of bad breeding genes. My second batch hatched under a broody. Out of the 5 hatched, 2 died in the first couple days. One had no apparent reason, the other was a vaulted skull chick who had clearly had a brain hemorrhage. I did an autopsy on this one and discovered the skull had a round hole in the top with brain matter protruding. The chick had obviously been pecked on the head or stood on which resulted in a hemorrhage and death. Of the remaining chicks, one had excessive yellow coloring in patches, and another has extremely short down and looks almost bald in places. There has been no exposure to chemicals or pesticides, the hens appear healthy and eat well on a mixed grain diet with separate oyster grit available constantly, kitchen scraps and occasional free range days. Can anyone give me their thoughts please?

 

[GitaBooks]

I'm sorry about what happened.

That is very confusing. Araucanas are known to suffer neurological issues, lethal genes (dying right before or right after hatching), and they may be inbred, but vaulted skulls? What other breeds were being kept with them? Did they have crests?

 

[Kamivy]

Thanks for your reply Gita. I know about the legal genes for the ear tufts,but araucanas in Australia do not have ear tufts so it's not an issue for us here. There are no other roosters with the hens so no chance of crossbreeding. Aust araucanas do have a crest, and I have recently been able to talk to a couple of breeders here in Australia who shed some light on the issue. Apparently they too encounter a small percentage of vaulted skulls each year and they recommended culling. As the vaulted skull is closely related to the crest gene, it can be a problem in Australian araucanas, especially in over crested hens. I examined my hens, in particular one who is over crested,and found she has a vaulted skull under her crest. So I won't breed from her again, and now that I'm aware of this issue I will be a bit more selective in my pairings. Thanks again for your reply!

 

[GitaBooks]

Thanks for your reply Gita. I know about the legal genes for the ear tufts,but araucanas in Australia do not have ear tufts so it's not an issue for us here. There are no other roosters with the hens so no chance of crossbreeding. Aust araucanas do have a crest, and I have recently been able to talk to a couple of breeders here in Australia who shed some light on the issue. Apparently they too encounter a small percentage of vaulted skulls each year and they recommended culling. As the vaulted skull is closely related to the crest gene, it can be a problem in Australian araucanas, especially in over crested hens. I examined my hens, in particular one who is over crested,and found she has a vaulted skull under her crest. So I won't breed from her again, and now that I'm aware of this issue I will be a bit more selective in my pairings. Thanks again for your reply!

That's interesting. Sorry, I was coming from an American Araucana stand-point. That's awesome that Australian araucanas don't have the lethal gene, and I've never heard of a crested araucana. I'll certainly do some research on them. Thanks for the info.

 

[SKL]

Thanks for your reply Gita. I know about the legal genes for the ear tufts,but araucanas in Australia do not have ear tufts so it's not an issue for us here. There are no other roosters with the hens so no chance of crossbreeding. Aust araucanas do have a crest, and I have recently been able to talk to a couple of breeders here in Australia who shed some light on the issue. Apparently they too encounter a small percentage of vaulted skulls each year and they recommended culling. As the vaulted skull is closely related to the crest gene, it can be a problem in Australian araucanas, especially in over crested hens. I examined my hens, in particular one who is over crested,and found she has a vaulted skull under her crest. So I won't breed from her again, and now that I'm aware of this issue I will be a bit more selective in my pairings. Thanks again for your reply!

That’s not true in relation to ear tufts in Australia Araucana, as I have Araucana located north central Vic, I have both morphs of hens. The crested hens lay a much lighter blue eggs, far smaller ear tufts, and no where near the head feathers (I consider these birds eggers). The chickens from the tufted and essentially uncreated hens (true Araucana) all have vaulted skulls, for which I have much difficulty successfully raising the chicks from the soft skulls due to mostly getting a peck on their heads from other birds I suspect.

As ALL pure Araucana possess the lethal gene.

The US bread the Ameraucana bred to over come the lethal gene.

The eggers are a crossed bird to solve the lethal issue also.

I also have chickens often with much yellow plumage at times, no matter the incubator, including my fully automatic Brinsea incubators that I find extremely reliable.