Moving Forward- Breeding for Resistance to Marek's Disease

[seminolewind]

My first go round with mareks was with tolbunt chicks. Iwish I had known to mark the ones that stumbled, had curled feet and split legs. Some survived. Later near point of lay some died but I don't know if it was those that survived from earlier or if it was some that never showed symptoms as a chick.

Seems there are certain times (possibly) that I have more deaths from Marek's. Generally between 6-8 weeks, 4 months, and 8 months. If they made it to a year old, they had a very good chance of being resistant. Not written in stone.

 

[seminolewind]

Quote:
This is all theorized by experience. I've had some that waste away with a smile on their face until the last few days when they sleep a lot and get lethargic. I've had one who came back from paralysis (vaccinated). I've had some that waste and gain and waste and gain. . I've had some that became symptomatic with paralysis, strange eye, loss of perception, wasting, all older than a year, possibly 1.5 year.

I also wonder about false negatives with Marek's on necropsy with chickens that have no symptoms and die from other things.

 

[speckledhen]

Quote: Me, too, Karen. After the loss yesterday, I have 41 total chickens- 31 LF and 10 bantams. Seven of the 41 are roosters. I want to get back to 20-25 total as well. If my old hens die off, that will do it for me, though. Of the 31 LF, 11 of them are 6-8 years old and 5 of them are 4-5 years old.

For young replacement layers, I have only four pullets, 25 weeks old (only one laying so far), and one pullet chick who is just 6 weeks old. Then I have only one 1-yr old and one 2 year old so not many.. I may end up having to buy eggs and I haven't had to do that except for one time in 9 years. It's getting close right now, though!

 

[seminolewind]

Unfortunately I have 6 roos. I only need 2-3. Sheesh.
I may be done with Polish and not replace any. I got a few Houdans that are absolute hug bunnies. I'd like to stick to just old or heritage breeds.

My Henrietta may be dying with ascites. I can't do a necropsy on her myself. But if she goes, I will definitely needle aspirate some fluid in her belly and maybe you can help with distinguishing the color. I've started a thread about her so I won't want to clog up this one. Just remembering something from you.

 

[speckledhen]

I've found that ascites is caused by something else most all the time. It's not pretty, is it? Did you see my thread on Hope where I removed 660 cc of yellow fluid from her recently? She still has more in there, but too much going on to do more for her right now.

 

[welasharon]

My tolbunts are surely genetically weak. There are so few of them. I love having them though...so what do you do?

 

[tridentk9]

Part of an article for pathologists on Marek's in very young chicks.

Under experimental conditions, EMS only occurred with some strains of MDV, and could occur, even in the presence of maternally derived antibody, albeit at reduced incidence.24 In the present case, it seems likely that the birds were infected by such strains, perhaps with a high infectious dose, and that they may well have had little or no maternally derived antibody to MDV.
In conclusion, the histopathologic, PCR, and immunohistochemical results presented here were all consistent with death due to MDV infection. To our knowledge, this is the first confirmed case of naturally occurring early mortality due to MD in chickens.

One thing to consider- if maternally derived antibodies will keep the chick alive until it's own immune system is better prepared for an assault- that might be a valid reason to vaccinate (as chicks) the hens.

Edited to add full article link http://m.vet.sagepub.com/content/48/5/993.full

 

[seminolewind]

My tolbunts are surely genetically weak. There are so few of them. I love having them though...so what do you do?

Not much you can do . I've decided to head more towards Heritage breeds. And not bother with the rarities anymore.

 

[seminolewind]

Part of an article for pathologists on Marek's in very young chicks.
Quote: Tridentk9, it's important for people to contribute articles. Please know that I'm not criticizing you, just the fact that there is very little out there that is current.

This is the type of article I question because of the dates of the material cited. 17 out of 24 resources here were from the 70's, 80's, and 90's. Although this article was written in 2011. The other thing is that all the cited resources state found in "Google Scholar" and the link is a dead end.

I also question what is written about 1 week old chicks when most common with Marek's is taking 4-6+ weeks to become symptomatic, which makes it seem to me that there would not be much found in a week old chick that was positive for Marek's.

Maternal antibodies I think, is more of a theory. I don't see how it matters with most chickens that need more than 2 weeks of protection from mom to build enough of an immune system against Marek's symptoms.

My 3 hatched from resistant parents and hatched by a resistant silkie , only one lived. The other 2 got paralysis and wasting and were euthanized.

But the biggest problem with articles found on line is that most are not current. And many are not dated. It's hard to get findings that are less than 5-10 years old.

 

[seminolewind]

I've found that ascites is caused by something else most all the time. It's not pretty, is it? Did you see my thread on Hope where I removed 660 cc of yellow fluid from her recently? She still has more in there, but too much going on to do more for her right now.

Do you have a link?

I had suspected something months ago, a very hard enlarged abdomen and then it went away. Her abdomen is large now but soft. There is a lump I can feel that is the size of a large grape. I agree I think it's related to something that I may not have had any control of.