Moving Forward- Breeding for Resistance to Marek's Disease

[Nambroth]

Northie, I am amazed at what animals are capable of.  I just can't imagine it being that cold.  

Nambroth, are you pulling my leg?

No-- really! -40° is when feienheight and Celsius match: http://www.onlineconversion.com/faq_11.htm

 

[seminolewind]

LOL, that's pretty cool.

 

[seminolewind]

Nambroth asked me on another thread about my antibiotic/cocci treatment. I had just got tired of skinny chickens, and I had a positive result with one hen so far, and am waiting for 6 others to respond. The food has been disappearing much faster.

I had a few necropsies and each showed at least one thing in common: opportunistic bacteria or cocci , one with e. coli. These bacteria and cocci are present in all chickens and kept in check by the immune system. Well, then they could be immunosuppressed. Why?

Your young chick or pullet comes down with paralysis. Or, gasping, not eating, the nerves connected to breathing and digestive system, or eyes. Marek's virus tumors will invade anything they can. It also causes immunosuppression. I went looking on how long that immunosuppression can last. Well it can be life long , and possibly affect vaccinated chickens as well (I'm not sure if this is rare).

If this is the case, then my wasting or skinny chickens may not be that way from Marek's, but from a suppressed immune system that allows the nasty bacteria to take over and make the bird sick. So I'm trying to find out if they are treatable illnesses, and not real Marek's wasting per say. Cocci seem to be a common culprit.

Does anyone appear to have "Marek's" wasting ?

http://www.addl.purdue.edu/newsletters/2005/spring/mareks.htm

http://blog.mcmurrayhatchery.com/2014/02/03/mareks-disease-by-dr-darrell-w-trampel-d-v-m-phd/

 

[gotthefever]

A little dirt don't hurt.

A generality but, children from overly clean, pet free, food careful homes may develop terrible allergies and immune issues. My floors are sticky, have dogs, cats, eat (sometimes) with dirty hands. I don't worry, they are building strong immune systems. I don't advocate touching public handrails, but...

I am just diagnosed with Mareks. I have 9 remaining. I think new 4 may have brought it, even with quarantine. They of course are not sick, and won't be because they are at this point in their lives, "shedders". Or I brought it from the farm store, how cavalier of me.

My dreams of hobby raising chicks I thought would be impossible for about an hour. I know it will take some more doing, but can be done. I can't compete with the giant hatcheries, they don't have Merek's...yeah, c'mon!

With the logistics of mixing breeds for shipments alone, the chicks are exposed, it would be impossible to not be, even with rubber glove, boy in a bubble type management.

So, now I have to figure. I will vaccinate any new chicks hatched here (if anyone survives) I can sell eggs and meat birds. I am not comfortable with selling hatching eggs, because I know I can not build a clean room and sanitize prior to shipping, at least for now.

New adults and juvs will be vaccinated, per reading, the vaccine may prevent tumor growth and mortality and morbidity.


And as you discussed, chicks4life, mixing breeds for heartiness. Something I was going to shy away from, but look at the success of the Labradoodle! Genetic diversity is ALWAYS hearty.


Am I living in a dream world, do I need to move to Alaska?
-A

 

[seminolewind]

It's such a sad crisis when it happens. I think we all learn how to get by.

 

[chooks4life]

A little dirt don't hurt.

A little dirt can prevent a world of hurt.

A generality but, children from overly clean, pet free, food careful homes may develop terrible allergies and immune issues. My floors are sticky, have dogs, cats, eat (sometimes) with dirty hands. I don't worry, they are building strong immune systems. I don't advocate touching public handrails, but...

I agree with that mindset, I've only ever encountered worse problems for myself and my animals when doing my best to avoid disease at all costs. Sometimes the costs of avoiding disease are higher than those of actually having the disease, or they enable what was going to be a mild problem to become unmanageably serious. I find they often cost you more, and for longer, than biting the bullet does.

New adults and juvs will be vaccinated, per reading, the vaccine may prevent tumor growth and mortality and morbidity.

Yes, it will, but it will thereby enable the susceptible animals to pass on their susceptible genetics instead of dying like they naturally would. To me, that's a highly questionable 'solution' because in the long run, by using the vaccine as protection for the susceptible, we're only breeding more and more susceptible animals which can suffer from Marek's related issues despite the vaccine.

It kinda ends up looking like a sticky, murky ethical dilemma in which there are no winners and no harmless routes to take. Digging a hole deeper and deeper doesn't get you out of it.

I don't know for sure about the immunosuppression some people are seeing, having not seen it myself, but it makes sense. The vaccine only stops one major symptom of the disease from occurring, it doesn't actually cure or immunize them. Each to their own though, nobody's about to stomach the idea of not vaccing their pets against it.

Some breeders I know are losing a percentage of stock every single year to Marek's despite vaccinating religiously. The weakest will always die and the strongest will always survive, unless of course we make such a muddle of things that we cannot identify our weakest and strongest lines, and thereby run the risk of only ending up running susceptible lines. Then, vaccine or not, you'll still always lose some, even potentially all, if you end up with weak enough lines. It's happened to many and doubtless will keep happening as long as we're applying bandaid solutions.

And as you discussed, chicks4life, mixing breeds for heartiness. Something I was going to shy away from, but look at the success of the Labradoodle! Genetic diversity is ALWAYS hearty.

Dog breeders that I chat with seem pretty down in the mouth about Labradoodles though, lol! They really scoff at the 'hybrid vigor' that's claimed for the 'breed' or cross... Though I hear America has an 'Aussie Labradoodle' which doesn't exist in Australia, which supposedly is now a breed in its own right? Some say you can't make a breed out of two combined breed names and lines, going by some rulebook or another... I don't know.

And with chooks (and other species), mixing two depressed lines can utterly fail to give you any hybrid vigor too, it's not a given just because lines were crossed out. Mixing two severely inbred or weak animals doesn't necessarily make any such magic occur. In my experience the strongest bird is not a crossbred, or a quarterbred, it's even more mixed than that, and came from a background of multi-generational neglect to boot.

If you had two fairly robust lines of Labradors and Poodles and crossed them, then definitely, hybrid vigor should occur, of course. But if they were really decrepit then like some people you would end up with a Labradoodle that has the problems of both inbred or sickly parent lines. Talk about copping the worst of the genetic lottery.

I think you could possibly, theoretically, inject some resistance into existing susceptible (and vaccinated) lines of a breed by crossing them with infected but resistant birds, possibly by similar methods to those used to exclude a disease from being passed from dam to offspring in goats or other species (anti-CAE breeding programs are worth looking into, as to how one can get disease-free offspring from dams carrying a vertically transmitted disease). It would take several generations to get clean offspring from infected lines, quite possibly, and probably involve three or more separate properties and some thorough ability to cleanse infective agents during transmission from one property to another... So, a collaborative effort between multiple parties would be necessary... These are all just theories of course, but there's always a way; some ways just haven't been found yet.

Best wishes, and good luck with your endeavors.

 

[ChicKat]

A little dirt don't hurt.

A generality but, children from overly clean, pet free, food careful homes may develop terrible allergies and immune issues. My floors are sticky, have dogs, cats, eat (sometimes) with dirty hands. I don't worry, they are building strong immune systems. I don't advocate touching public handrails, but...

I am just diagnosed with Mareks. I have 9 remaining. I think new 4 may have brought it, even with quarantine. They of course are not sick, and won't be because they are at this point in their lives, "shedders". Or I brought it from the farm store, how cavalier of me.

My dreams of hobby raising chicks I thought would be impossible for about an hour. I know it will take some more doing, but can be done. I can't compete with the giant hatcheries, they don't have Merek's...yeah, c'mon!

With the logistics of mixing breeds for shipments alone, the chicks are exposed, it would be impossible to not be, even with rubber glove, boy in a bubble type management.

So, now I have to figure. I will vaccinate any new chicks hatched here (if anyone survives) I can sell eggs and meat birds. I am not comfortable with selling hatching eggs, because I know I can not build a clean room and sanitize prior to shipping, at least for now.

New adults and juvs will be vaccinated, per reading, the vaccine may prevent tumor growth and mortality and morbidity.


And as you discussed, chicks4life, mixing breeds for heartiness. Something I was going to shy away from, but look at the success of the Labradoodle! Genetic diversity is ALWAYS hearty.


Am I living in a dream world, do I need to move to Alaska?
-A

Just a word gotThefever --
To my understanding Marek's is not transmitted through the egg.

 

[seminolewind]

True, Chickat. It can't even survive on an egg shell thru incubation from what I've read.
I also find that Marek's-exposed chickens get immunosuppression. They can catch so many ailments that I've started to treat for bacterial illness or cocci when they waste. A lot of times the ailment is sub clinical, and the only thing you'll see is a bird that's wasting, or kind of not thrifty.

 

[Northie]

Off topic but it was mentioned someone mentioned the doodles above and I just wanted to chime in that not all of the doodles are turning out to be the miracle cross that they are portrayed and hyped up to be. If the parents of the doodle puppy's were susceptible to health and temperment problems then they will just as easily pass these defects on to their mix breed puppy's as they would purebred puppies. Golden's, labs, and a good portion of other large dogs (mixed or not) are susceptible to hip and elbow problems... Crossing them with a poodle (who should also be tested for these problems) doesn't magically make them dissapear. Skin problems show up too, same with allergies, if either of the parents had iffy temperaments they can pass this on to the pups. Then there's the crazy notion of the coat being low maintenance and needing very little care, no sheding, no brushing... If it doesn't shed - its high maintenance - it never stops growing and you need to brush it or clip it faithfully to keep your dog comfortable. If you don't have to brush it and it is a low maintenance coat it sheds and it is not likely to be hypoallergenic.
You can get a nicely bred doodle that will be healthy and a wonderful dog but this is not just because it is a cross breed, its because the breeder started with healthy, sound tempered dogs. The same can easily be said for buying a purebred dog, healthy parents clear of genetic defects are the best bet for producing healthy puppies.
Right now designer dogs and mixed breed dogs hugely out number purebred dogs and that isn't making our dog population healthier. In fact I'd say because of the notion of "hybrid vigor" there is less though being given to the health and genetics of the parents when people are breeding.
When ever you're planning a breeding (purebred or not), you should consider the best, and the WORST offspring that will come from the cross and assume you could get anything from one extreme to the other. An easy example - breeding beautiful and dull to ugly and brilliant, you could get anything from beautiful and brilliant to dull and ugly...
Just something to keep in mind

 

[ochochicas]

Me being the biology major that I am, I immediately set out to find as much information as I could...only to be bitterly disappointed. There seems to be three different camps on how to deal with MD- depopulate (old timers said to burn the chicken house to the ground with the chickens in it. Not happening.) and wait AT LEAST one year (studies have found the virus to survive for 65 weeks), keep a closed flock & vaccinate any incoming birds, and lastly, breed for resistance. This last group seems to be woefully small....

This is a great thread! I'm going to go through and read the whole thing when I have more time. I'm sorry your flock got Marek's despite all the measures you took to protect them.

I got a carrier bird last year which infected all the chicks I hatched last summer and fall. So far I've lost nearly every bird except for one cockerel and three pullets. None of my australorps have been affected by the virus, so I think they are resistant. I start to think that the chicks that hatched from eggs laid by my older hens (the australorps) were resistant, but then I remember that all my Marans chicks were the first to die and that hen is old like the Australorp.

I'm a biology major, too! I wanted to do what I could to save my next batches of chicks. I am double vaccinating everyone and isolating them for at least 3 weeks before letting them out of their chick-ward where they might come into contact with the virus. My first set of vaccinated chicks are 12 weeks old and have been with the Marek's carriers for the last 3 weeks. I am nervous about what the future holds, but also excited to see if they will make it through the year. I'm not going to try to create resistant birds at this point since I don't think my heart can take the idea of culling any more of my pullets this year.