Do you test for MG ?

Do you test for MG?
I'm curious, how many people on WCPS have tested their flocks for Mycoplasma Gallisepticum ?  What are the results? What have you done with your flocks if they are positive?  Is anyone trying to Stop the spread of this disease?

Has anyone imported chicks from the US that have been vaccinated against Mycoplasma Gallisepticum?  I know the vaccine against MG is available in the US.  I'm curious if any of the Hatcheries will vaccinate chicks they export to Canada.  Do any of you vaccinate against MG?

I have culled many MG positive chickens already, and have more to do.   I culled my beloved Silkies. It broke my heart.   I really miss them. I loved my Silkies

I want to get some more Jumbo French Guinea Fowl, but promised my self not to bring any poultry that aren't tested onto my property.  My Jumbo French  Guineas  have been tested and are negative .

What happens if you mix vaccinated and non- vaccinated (but healthy) chicks?

Stopping the spread of MG is akin to trying to stop the common cold. A lofty goal that has no hope of success. It's a much more realistic and sustainable goal to manage MG. Unlike with the common cold, we chicken breeders have an advantage in that we can select for MG resistance within our flocks.

MG is a pain in the butt. So is MS and Coryza. All three are common, all three amount to chickens with cold symptoms (respiratory), and all three cannot be cured. Additionally, they all pass through the egg. All three hurt the productivity of our flocks. I fail to see why one would focus on one over the others. We backyarders need to get a handle on all three.

As we go down the road of figuring our how to deal with respiratory diseases, it's important to realize that the 3 diseases are opportunistic and become a problem in stressed flocks (again, like our common cold).   It's also important to realize that some genepools are going to be genetically more resistant than others. I feel it's also important to keep in mind that back when heritage breeds were the only chickens available, MG was pretty much found in all flocks. It was simply part of the environment and the breeds still found a way to evolve, thrive, and feed alot of people. In the years since, our husbandry practices have changed and our heritage genepools have deteriated.

Husbandry is the key to managing respiratiry diseases such as MG. Both by avoiding the kind of stresses that trigger respiratory diseases, and in culling ALL unthrifty birds. Every bird that shows symptoms should be euthanized. Or if one is considering treatment, should at least never be used as a breeder.

This leads me back to the opening question of whether we test for MG? I'm not sure I see the benefit. If a birds gets watery eyes or the sniffles, it's removed from breeding contention. Does it matter if the cause is MG as opposed to another respiratory disease?

If testing otherwise healthy stock, then what are we actually testing? Does the test look for antibodies, or the actual disease? Is the test simply identifying those birds that have been exposed but are resistant? If testing otherwise healthy birds, would discarding the birds that test positive actually cause one to be throwing away the disease resistance genes? Selecting against disease resistance makes absolutely no sense and seems more destructive than helpful.  

Therefore, before deciding to test my birds, I would need to be educated in how testing would aid in responsible selection of breeding stock, or in how the opinions/assumptions I expressed above are wrong.

Debbie, at the time I first met you and Monica, respiratory disease was not on my radar. I was at the tail end of cleaning up the symptoms of inbreeding depression in my mixed Araucana/Ameraucana flocks. I had already invested 4-5 years into lethally culling unthrifty birds (mostly coccidiosis) and selecting for weight. I was just starting to divide the genpool into the 2 breeds (4 varieties). We had just started with the Rhode Island Reds.

I had a couple of good years and then respiratory disease hit us hard one summer. Two things happened that year. First, I imported some game birds from Alberta that started getting watery eyes and the sniffles within a week of arrival. I just chalked it up to them not being adapted to our west coast climate and adjusted my husbandry accordingly. The disease was held in check, but never really left. Then I babysat a friend's birds which included some Silkie cockerals that had watery eyes. They joined my cockeral pen.

Within a week, I noticed watery eyes on my cockerals and once I confirmed that the disease was indeed spreading, I started lethally culling every cockeral bird that showed watery eyes. Including my friend's! It wasn't long before I started seeing symptoms in all my pens and this disease seemed different than what came with the Games. So now I had at least two respiratory diseases running through my flocks. By the time the dust settled, what was remaining of my friends birds were back with her. I Had culled about 20% of my Ameraucana and Araucana flocks, 50% of the Rhode Island Reds, but then hit a snag with the Games. Every single bird ended up showing symptoms.

Those that know me know that I have an arrogant confidence flowing through my veines and in this case, it caused my to make the complicated choice rather than the easy one. In hindsight, I probably should have just culled the flock and saved myself alot of grief and expense. However, given how well my Ameraucana/Araucana flocks responded to the disease outbreak, I knew my selection and husbandry approach works. The Games just needed some resistance genes and time for proper selection to do it's tricks. I turned to Paulie, a mature 8 pound wheaton araucana who was living in the cockeral pen (peace keeper) when the disease was introduced. He survived what I call ground zero without a sniffle and with his head. I cleared out the Rhodies, wheaton Ameraucanas, and then later the Araucanas to make room.

For about a year, I picked the strongest best fleshed Game hens and used antibiotics, a vaccine, and alot of pampering to get and keep them symptom free. I was operating under the advice that symptom free birds are unlikely to transmit the diseases. The resulting F1 gave alot of hope, I liked the vigor and productivity. Of the chickens, they were my best winter layers. Unfortunately, they looked more like my Araucana line than a Game. The F2 season showed the weaknesses, giving me some disease resistance to select for, but really didn't excite me. The best potential breeders still looked like mutts and anything that looked like a game proved to be unthrifty or too slight in stature to keep. 2014 was basically my F3 generation and I saw a significant return of respiratory disease in the chicks. It's my understanding that 2014 was an overall bad year for backyarders. I lethally culled roughly 60% of the year's hatch. However, of the survivors, I found some individuals that really exited me. I found 3 boys that could legitamately pass as Games and boy were those boys beefy and strong despite sleeping under the stars. The tallest was 30" and had the curves. I had a dozen pullets that I wanted to hatch from. I really couldn't wait to check out their offspring.

Then I did my year end books and faced reality. Simple fact is that I didn't sell enough roosters to sustain 2 breeds. The local backyard marketplace didn't seem overly interested in helping sustain the heritage breeds by buying frozen dinner when buying POL pullets. Some great souls did, but not enough to justify maintaining 2 breeds. By this time, I was down to the Black Ameraucanas and the Games. As much as the games got under my skin, and fixing the breed would be a huge boost for my ego, I simply could not turn my back on the Ameraucanas. I built them from scratch and have had them since day 1, fourteen years ago. They have far surpassed my initial goals and I take alot of pride in them. I put my last games in the freezer last week. The 8 month boys dressed out to 6.5 - 7 pounds

I cried. Then I walked throught the various chicken pens looking at the Blacks. What a beautiful sight. I'm now looking forward to a hatching season where they are my only chicken focus and I don't need to be dancing around trying to manage respiratory disease.

Very interesting Omega Blue thanks for sharing. So did you ever confirm what respiratory issue was in your case? What was considered un thrifty in your eyes and when did you decide to cull? Do you think you have built up a resistance to it in your flock? I've read quite a bit now on MG and MS and there is a lot of conflicting information out there.

OMG OBFs! Thank you SO MUCH for sharing this. Yours are the first posts on MG that I have read in an ocean of comments on the disease that made perfect sense and which I agree with.

I am not saying this to ridicule others comments on MG. I don't take lightly those who have lost their flock to MG or decided to euthanise their flock because of a positive MG test result. I have done my own researching and questioning about the disease. I have read the pros and cons of vaccination. I have read and looked into testing my flock. I have found myself leaning to one side then the other again & again as I have read people's comments. Till finally I find myself burnt out on the topic of just MG itself. Especially now as some people I know have become so firm in their opinions that they are unwilling to accept that the disease is not a new one. MG is one of a few poultry diseases that due to their nature will never go away. It will always be here in one form or another.

I am now of the opinion that we ourselves have become the problem. MG in backyard flocks is something that is best controlled the old fashioned way. Basically the exact way Omega Blue Farms dealt with it. As flock owners we already have the tools. There has been SO MUCH talk about MG in recent years that we know the DOs & DON'Ts of what could bring MG into our flocks and what can trigger an outbreak amongst our flocks. MG testing is becoming more readily available. If one wants to test and it brings back a Positive result, one does not have to euthansize their flock. I have heard of several people who were told by their provinical vets that management was perfectly OK. I really believe that the one option often thrown out with the bath water is resistance.  Why are some birds not affect by MG within a Positive flock? Maybe it should be looked into more seriously than it currently is?

Yes Wayne I remember, I bought some. I also bought one of your beautiful Black girls, she laid the best huge olive eggs. She had a great temperament. Thank you for your thoughts. I've been agonizing over which way to go. In the summer I got hatching eggs, great fertility 100%. Hatch ability was poor. I ended up with 1 chick out of 2 dozen + eggs. The cockerel ended up with what I suspect was  MG, I culled it.

I agree CRD's and MG is everywhere. Keeping a closed flock is one way to go. My layers are laying very well at the moment.  None of my layer flock showed any symptoms, until this past few weeks, cold, foggy, wet,  miserable weather.  As they show up with symptoms I cull.  That's not the worst problem I have with MG, the death rate in chicks is.

I posted this question on here and ACE out of curiosity, and to see what people's thoughts are and what they would do if they had  MG.  I'm not judging anyone. That was not my intent.

How one approaches the question is dependent on what one wants from their poultry. There are really two camps, one that simply wishes to enjoy and/or utilize poultry. The other is attempting to support some degree of conservation breeding.

As a nation, Canadians, it's poultry industry, and the institutions supporting it do not consider poultry from a conservation standpoint. Therefore, the advice one would get would most likely ignore the implications to conservation. This is just a reality of where and when we live.

Vaccines and disease testing are excellent tools that support the needs of those utilizing poultry, whether it be for production or as pets. Since the Vaccines and disease testing is being used in the production of end products (not breeding stock), it does not interfere with the long term sustainability of the genepools in question. Hatcheries selling end products should be vaccinating and testing their flocks to best serve their customers. Those just wanting pets and/or production would be best served by only buying from vaccinated and tested flocks. It's the safest bet.

Those that wish to support and contribute to the conservation of heritage breeds do so in contrast to our national agenda and therefore will need to go beyond our institutions for relevant advice.

Vaccines and testing interferes with responsible selective breeding, I do not see any use for them except in rare cases. Breeders that rely on Vaccines and testing will accomplish one thing, they will select their line(s) to be increasingly vulnerable to the diseases in question and increasingly dependent on the drug companies for the welfare of their breeding outcomes. This is not an opinion, not a judgement, it is a simple fact. Any advice to the contrary is advice that undermines the goals of the conservation breeder.

For several years, I have tried distinguishing my efforts from those of a hatchery. I make it clear on my website that I'm not a hatchery. This issue is one of the reasons why.

In an ideal world, breeding flocks and hatchery flocks are two separate entities with completely different styles of husbandry. While breeding flocks benefit from low but consistent levels of disease exposure, the hatchery flock needs to be 100% isolated from diseases. Realistically, they need to be on different farms. I'm just a poor dirt farmer on 10 acres, I don't have the resources to do both. I choose to defend my food independence by maintaining breeding flocks, even though doing so is in contrast to our national agenda. I sell breeding stock and food, but I'm not a hatchery.

Well said OBF ,I totally agree!!

I read the following on another site.

"All info I've read said you cannot breed resistance or immunity to it." in reference to MG.

My comments are not for the person who was kind enough to share the statement. I thank that person for putting the information forward so that it can be addressed. My comments are for the sources of such misinformation.

Many are quick to defend differing opinions and suggest that we must treat all with respect. I agree to a certain extent. However, when a statement is in direct contrast with common known facts, it stops being an opinion and becomes a bold face lie. It's a shame that so many good-natured people are spreading this lie, but that detail does not make it any less a lie.

Anytime there is variation within a genepool, selective breeding can select against that variation, and change the gene frequencies of that genepool in the direction of the breeder's choice. The simple fact that some breeds are more resistant to MG than others and moreso the fact that not all individuals within a flock are equally effected are undeniable clear indications that there is a genetic component to MG susceptibility. This is genetics 101 stuff and the very essence of breeding. One requires variation for selective breeding to work AND selective breeding can reshape a population whenever sufficient variation allows it.

This reminds me of a conversation I had during the fallout of the first avian flu cull. The province had teamed up with CFIA to hold meetings between the government and industry stakeholders. Following one such meeting, I had an extended conversation with one of BC's avian pathologists. The person struck me as a sincere kind hearted soul whom I took an instant liking to.

My argument was that the provincial response was killing BC's poultry genetic infrastructure, and that by killing healthy birds on infected BREEDING farms, the province was wiping out our resilience to future disease concerns. I suggested that backyard breeders such as myself were doing valuable work and that the future of such work should not be overlooked. I then used my turkey flock as an example. Commercial turkeys are highly susceptible to blackhead and really need to be isolated from chickens to perform well. I then pointed out that I had selected my flock to be blackhead resistant. She expressed skepticism whereby I added further details like how I merged a feral flock with mine. My initial flock did not suffer much from blackhead, but as expected, the feral flock proved to be extremely vulnerable to blackhead and I ended up culling something like 80% of the first generation. It was only about 3 generations later that blackhead again became a non concern. Her explanation was that my observations of reduced blackhead incidence was most likely due to improved husbandry.

Now, I'm sorry, but such a response demonstrated a profound level of ignorant arrogance. Yes, as I said, she seemed like a kind hearted sincere individual, but obviously her education was sadly lacking and biased. Especially when one considers my husbandry methods whereby most of my turkeys refuse to sleep under cover and instead spend most nights sleeping on fallen logs fully exposed to the elements. If anything, my husbandry methods would expose blackhead vulnerability, not mask it.

Those institutions providing advice to the poultry community have, for several decades, been extremely biased against traditional knowledge. The lie about one not being able to selectively breed MG resistance into a line is just another example of such bias.

If anyone disagrees with my assertion that that statement is a lie, I'm open to being proven wrong. I'm open to an academic based open (public) debate on the issue.

I was not going to comment on this thread, here, although I am reading it. Omega, you have prompted me to make a comment or two. I admire how my forum friends have and are dealing with mycoplasma gallisepticum (I cannot stand acronyms so will spell this word out in full). I honestly and truly do not believe that any birds in my flock have had this disease. We have lived in the Okanagan now, close to 5 years, having moved here from Maple Ridge back on the south coast of BC prior to our move here. I think that back on the coast, in the first beginnings of my involvement with breeding chickens, that I might have had that disease, but only with a few birds. None of the birds that might have had the disease on the coast are with me now. I have 100% new stock, except for my 3 matriarch blue cochin gals. They are coming up to 6 years old now. They never showed ever any symptoms of any illness through their long lives...ever...healthy as the healthiest of healthy could be. Since that time I have brought in hatching eggs, purchased roosters and hens and have been breeding. I have not been breeding for any resistance really to anything. But I think every bird in my flock is 100% healthy. I have never had any serious illness in any of my birds. I have had about 4 years ago, a very small bout now and then of marek's disease (I still will not capitalize this disease's name because it is not worthy of that, smiling), and coccidios, a few years ago, but so minor, I have almost forgotten about it. I do not consider any of my breeder flock resistant to anything, but I think they must be. I am fairly sure that I do not have mycoplasma gallisepticum, because even through every stress the flocks go through, and there are many, many things that can cause stress in chickens, even at the most stressy times of year, there has never been a symptom of this disease. I should not say I know, because I actually don't know that I am free of this. I think I am free of this, because I think that if any of my flock was carrying it, that disease would have in one way or another, raised its ugly head. I am not and will not ever say that my birds DO NOT HAVE it for sure, but I think not. And...I will never profess either that my birds might not get it. If that disease comes around, I am sure that my birds will get it. And I will test and react I would suppose. I would think that I would cull. But having not had to deal with any illness, ever...I am not sure what my reaction would be. I am not trying to come across as arrogant, just sayin' that I think my birds are disease free. As far as I know. Now, as for closed flock. Yes. I think that is a very good idea. At this point in time, my progress with my breeding is going along well. I do not see any need for bringing in any new blood at this time, as I see leaps and bounds each year with improvement with my buff orpington and cochin breeding work. I fear now that if I brought new stock in, that I could bring some evil with that. So for now. My flock is closed and I will keep on selecting the best from what I have. I am not worried about inbreeding yet. My cochins are 100% fertile. Buffs, well, I am in the process of butt feather plucking to improve this bit of a fertility lacking. Running about 50% fertility right now (improvement from earlier this fall). I really do believe that the boys and girls are too fluffy butted for proper cloaca kisses. Some nice kisses are happening, clearly, but I think not enough, or just favourite gals are being chosen for partners. This too is being rectified with conjugal visits, smiling that big smile. Anyways, my two cents. This is a most valuable topic and I am very happy, Wayne, that you have given us your experience, experience is what makes this world go round and round and round. it is a good thing. Have a wonderful day, CynthiaM.

I am reading this thread with great interest, as I am starting a new flock this year. I have not had chickens for many years. I plan on bringing in hatching eggs of one breed from two different sources, and some day old chicks, of three different breeds, from Ideal poultry. I assume that the day- olds from the hatchery are MG free- but now I am worried a bit about the hatching eggs. I'd like to keep a closed flock after these imports and of course I'd like my flock to be disease free.
The Merck manual says that :    In valuable breeding stock, treatment of eggs with antibiotics or heat has been used to eliminate egg transmission to progeny.
How would I heat treat the eggs? They are being shipped a long way and I am already concerned that their viability will be low. However I'd rather have no chicks than diseased ones.

Would I be better off if I stick with ordering all the breeds I want from the hatchery? The hatching eggs would of course be better representatives of the breed....... but there is the potential of bringing in disease. I am not interested in showing.
Thanks for any advice you can give.  I don't want to find things out the hard way!

Derbyshire wrote:I am reading this tread with great interest, as I am starting a new flock this year. I have not had chickens for many years. I plan on bringing in hatching eggs of one breed from two different sources, and some day old chicks, of three different breeds, from Ideal poultry. I assume that the day- olds from the hatchery are MG free- but now I am worried a bit about the hatching eggs. I'd like to keep a closed flock after these imports and of course I'd like my flock to be disease free.
The Merck manual says that :    In valuable breeding stock, treatment of eggs with antibiotics or heat has been used to eliminate egg transmission to progeny.
How would I heat treat the eggs? They are being shipped a long way and I am already concerned that their viability will be low. However I'd rather have no chicks than diseased ones.

Would I be better off if I stick with ordering all the breeds I want from the hatchery? The hatching eggs would of course be better representatives of the breed....... but there is the potential of bringing in disease. I am not interested in showing.
Thanks for any advice you can give.  I don't want to find things out the hard way!

There is no guarantee that hatchery chicks are disease free. No more than hatching eggs.

Here is a link on egg dip treatment you might find interesting.

[You must be registered and logged in to see this link.]

Thank you toybarons for posting that link. I was trying to find some more information and that was perfect. I am going to contact Ideal and find out what their MG prevention protocol is.

I found the following on another site. The author speaks alot of common sense, or at least I think so. I sing the same tune.

[You must be registered and logged in to see this link.]
KazJaps   02/13/04 10:35 AM
Loc: Australia
I totally agree with Caveny in that the easiest way to proceed would be to destroy this flock & start again. But is the immediate destroying of positive flocks the only available option for disease management? Well of course, no! Is the eradication of positive flocks, in every situation, always the most practical & effective method of disease control? Once again no!

These are questions that immediately come to mind:
With the destroying of flocks:
1: Are you able to find clean replacement stock & of the genetic quality that you seek?
2: What is the probability of reinfection to a new flock?
And if you keep positive birds:
3: How prominent are Mycoplasmas in your area & where would YOU be spreading Mycoplasmas to, especially if many other small flocks are positive? Certainly not to others that practise biosecurity.
4: Is there a possibility of disease containment (ie quarantine)?
5: If there is little possibility of disease containment then what does this imply about the likelihood of reinfection of a clean flock?
6: Are there positive birds in the flock showing resistance to disease? These resistant birds are valuable in breeding programs. Part of the problem with eradication programs is that if All surviving birds are eradicated in a flock, genetic resistance is not allowed to develop in a population.

And this leads to the next question that keeps coming to mind. Why are some people once severely burned by diseases relying totally on other breeders to do all the hard work in establishing clean & resistant breeding stock? Why aren’t they doing this themselves? Where are you going to get clean stock from if everyone keeps killing their flocks and passing the buck on to someone else? And will the few clean flocks available provide RESISTANT breeding stock or are all the tested resistant birds being killed in the process of positive flock eradication?

Quote: "Unfortunately it WAS by culling that commercial flocks were cleared of this disease."

But you see, all commercial flocks are NOT clean of Mycoplasmas. The eradication programs worked well with commercial breeder flocks, but Mycoplasmas still occur in production birds (& Caveny mentioned previously it still occurs in breeding stock). Do all commercial operations immediately kill off production flocks when found positive to Mycoplasmas? No!!! If keeping flocks clean of Mycoplasmas is difficult for commercial operations, what are your chances of keeping your flocks clean? Now apply this to your own situation and take a realistic look at the likelihood of providing such strict biosecurity to your own flock. Remembering here, that you are literally putting all your eggs in one basket, relying totally on isolation as a defence mechanism. One slip up means destroying your flock & starting again.

Successful eradication of Mycoplasmas in breeding flocks was not achieved by the immediate killing of all breeding flocks found positive to MS & MG. Why would you do this when it is known that a high percentage of flocks are positive? You would be losing valuable breeding stock & eradicating a large percentage of the gene pool, including proven RESISTANT stock. Such eradication programs of well-established & wide spread diseases are not achieved overnight. It is my understanding that part of the eradication program entailed segregation (isolation) of breeding stock, treating breeder eggs, gradually eradicating infected parent stock & keeping the clean (isolated) offspring for the next breeding generation.

I do not see where the eradication of all small flocks found positive to Mycoplasmas will achieve anything productive, in situations where it is known the likelihood of reinfection is very high & when such a high percentage of the population is positive. Be realistic here. What are you achieving? Yes, if you know you have a high probability of successfully isolating your stock from Mycoplasmas, by all means, buy TESTED CLEAN stock & keep in strict quarantine. But if you are contemplating exhibiting any stock, well forget about relying on biosecurity alone, unless it is a one-way trip to the show, and forget about free ranging if there is the slightest possibility of contact with wild animals. The risks are just too high. There are no commercial flocks in Australia positive to virulent Newcastle Disease. So why has the government decision been made for the compulsory vaccination of all commercial flocks? What, isn’t the quarantine practises enough?

Take this into consideration. The majority of small flocks are positive to Mycoplasmas. Are all of the birds in these flocks showing signs of disease? NO!!!! It is the misconception I keep reading that if an animal is positive to a pathogen or is positive to antigens, it must be diseased. WRONG!!! I can’t remember now where I read this but I think it is that a large percentage of the human population carry the herpes virus responsible for the common cold sore. But it is only a minority of people that ever develop cold sores (disease). Now put this into a poultry perspective. Would you eradicate all individuals found positive to the virus or would you use the large percentage of individuals found resistant, in breeding programs? In a wild bird breeding program, would you prefer to have wild birds from the UK (found positive to antigens of the West Nile virus, therefore signs of resistance) or wild birds in the USA tested negative to West Nile virus antigens but found susceptible to the disease? The ideal would be breeding stock negative to pathogens & tested resistant to disease. But how many backyard breeders have the resources & money to do this sort of lab work?

In my situation, the reliance on biosecurity alone is such an unrealistic gamble on the health of my flock, that if I did this I would be totally irresponsible. It is much more sensible for me to prepare for the likelihood of exposure to common diseases in my area. I do this by selection/breeding of birds found to have resistance to low mortality diseases & vaccinating for the virulent diseases in my area.

If anyone wants to read up on genetic disease resistance “Poultry Breeding & Genetics” has a lot of information on the topic.

I do know someone personally who is in the process of eradicating Infectious Coryza from his breeding stock. He is achieving this by setting up a quarantine area for infected parent stock & artificially incubating eggs, rearing young stock in another quarantine area. He doesn’t buy birds anymore, never exhibits birds & lives on large enough acreage for a quarantine system to be successful.

Quote: "If my cat or dog became ill with a disease that would infect every other cat or dog they met then yes I would definately have them culled.I would expect everyone to do the same."

Why would you kill your cats, dogs over some disease that has such a low mortality rate? Why do you believe you would HAVE to kill your pet & why would you be letting a positive animal have contact with other animals? Ever thought of vaccines? Does your vet advocate killing all pets found positive to infectious diseases or advocate the vaccination of all animals? Wouldn’t he/she be doing everything to save the life of an infectious animal?
Why aren’t you upset that people DO NOT kill off all flocks found positive to Marek’s Disease? Why aren’t you upset that no one is doing anything about eradicating coccidia? Why people have been letting protozoa spread everywhere! I don’t know, I hope I’m not the only one out there that doesn’t immediately think about gathering a possie together & stringing someone else’s neck because OUR birds have contracted a disease. Unless someone has intentionally come in to my chook yard carrying an infectious disease with the sole intention of infecting my flock, the sole responsibility of my flock’s health is ALL MINE!

and here are some tidbits from the science community:


[You must be registered and logged in to see this link.]

Avian Dis. 1990 Jul-Sep;34(3):607-10.
Factors affecting the development of respiratory disease complex in chickens.

" Resistance of chickens that had been selectively bred for a high (HA) or low (LA) antibody response to sheep erythrocytes was compared. HA chickens were more resistant to respiratory agents and less resistant to E. coli than LA line chickens. When the lines were exposed to respiratory disease followed by exposure to aerosols containing E. coli, the HA line had the lowest incidence of pericarditis and death."

*******
Poult Sci. 1980 Feb;59(2):205-10.
Production and persistence of antibodies in chickens to sheep erythrocytes. 2. Resistance to infectious diseases.
Gross WG, Siegel PB, Hall RW, Domermuth CH, DuBoise RT.
Abstract
A line of chickens selected for ability to product high antibody titers to sheep red blood cells exhibited stronger antibody to Newcastle disease, was more resistant to Mycoplasma gallisepticum, Eimeria necatrix, a splenomeglia virus, and feather mites and less resistant to Escherichia coli and Staphylococcus aureus infection than a line selected for a lack of ability to produce antibody titers. A line of chickens selected for a nonpersistance of antibody titers to sheep red blood cells was relatively more susceptible to all infectious agents tested than a line selected for a persistence of atibody titers.

**********************

Avian Dis. 2002 Oct-Dec;46(4):1007-10.
Effects of genetic selection for high or low antibody response on resistance to a variety of disease challenges and the relationship of resource allocation.
Gross WB1, Siegel PB, Pierson EW.
Author information
Abstract
Lines of white leghorn chickens were selectively bred for either a high (H) or low (L) antibody response to sheep erythrocytes. The parental lines, HH and LL, and reciprocal crosses, HL (sire line cited first and dam line second) and LH, were compared for their responses to various diseases. High antibody titers were associated with reduced body weight. Lines and their crosses were challenged with infectious diseases. The LL line was most resistant to Mycobacterium avium, whereas the HH line was most susceptible. The HH line was most resistant to Mycoplasma gallisepticum, whereas the LL line was most susceptible. These findings indicate that defense against infectious diseases are resource expensive. In order to save resources, it is possible that different parts of a population might genetically devote high levels of resources against different types of diseases so that the entire population is not susceptible to a single infection.

************************************

Poult Sci. 1998 Aug;77(:1111-8.
Impact of genetics on disease resistance.
Lamont SJ1.
Author information
Abstract
The genetics of a bird or flock has a profound impact on its ability to resist disease, because genetics define the maximum achievable performance level. Careful attention should be paid to genetics as an important component of a comprehensive disease management program including high-level biosecurity, sanitation, and appropriate vaccination programs. Some specific genes (e.g., the MHC) are known to play a role in disease resistance, but resistance is generally a polygenic phenomenon. Future research directions will expand knowledge of the impact of genetics on disease resistance by identifying non-MHC genetic control of resistance and by further elucidating mechanisms regulating expression of genes related to immune response.

**********


ZEKARIAS et al. 2002. Immunological basis of differences in disease resistance in the chicken.

"Improving the genetics of disease resistance is the most eligible approach for sustainable control of infectious diseases in poultry."

Hatchery stock is not usually  'better representative of the breed"   often the exact opposite. Toybarons gave a good link.

Wayne my Jumbo French Guineas are in with my flock. They tested negative for MG.  The majority of my flock have never shown any symptoms.   The culls were my Isa Browns, hatchery stock. I'm working with Monika, we are trying to get a MG clear flock. I'm not saying it's possible, but we will give it our best.  

If my flock get reinfected I'll deal with that when it happens. I believe it's possible to build up, if not natural immunity, at least natural resistance.   This is why I'm pleased my Guineas are MG free.
I try to not cause hurt or harm to any living creatures.