Ameraucana Forum
The Official Ameraucana Forum => Breeding => Topic started by: Michelle Ogden on May 04, 2015, 07:21:31 PM
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I've had two out of 20+ lavender/split chicks with crossbeak. Shows up around 2 weeks old.
Does this mean both the cock and hen should not be bred? Or would it just be carried by one of them? Or is it something like Down syndrome, where it is a random genetic anomaly, and I just got unlucky?
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Some lines have a propensity for this showing up, more than others. With some lines you seldom if ever see it occur. Wheaten bantams used to be quite bad for it, but I don't think so much any more. Select for short, stout beaks and I believe you can breed it out of a line with enough time and effort.
Another thing you can do is check the shape of the beaks. If the top mandible is curved and the lower one is straight, that is not good. Especially if it leaves a gap so you can see daylight between them from one side to the other. Stay away from parrot beaks too.
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Both the chicks did not show any signs of it the first week of life. Perfectly straight beaks, indistinguishable from the others. I don't hatch in huge quantities, so my chicks get a lot of attention. I most definitely not keep a chick with an "off" beak for breeding. I'm just curious about the genetics of it, as I've sold chicks and hatching eggs and worry about the odds of a customer getting one with crossbeak... Or worse, perpetuating the problem in their flocks with carrier birds. :(
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It takes a few days or maybe up to a couple weeks before they show up. I generally see a few crossed beaks show up in some of my varieties of bantams each year...normally the silvers and lavenders, but I've had a couple buffs already this year. Sometimes there are crooked and curved (left or right) beaks also. My personal opinion is that they are all similar to cleft lips and palettes in humans.
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I'm just curious about the genetics of it, as I've sold chicks and hatching eggs and worry about the odds of a customer getting one with crossbeak... Or worse, perpetuating the problem in their flocks with carrier birds. :(
I don't think anybody knows for sure, but if I had to guess I would say it involves two recessive genes working together to cause the crossed/scissor beaks. If that is correct, and you wanted to eliminate the problem altogether, you would not use any bird that threw crossed beaks. But you might want to save a couple to test mate with, one male to test females and at least one female to test your male(s). I never found it to be worth the bother, but I could see why someone might want to eliminate the problem from their flock.
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This was a problem with my LF Silvers I believe in my instance it was from my foundation flock being to small. In the beginning I didn't keep enough cockerels to increase the gene pool. After a couple years I purchased another trio from the original line and started really keeping track of matings. Either by luck or by increasing the genetic make up of my flock I have drastically seen less in the last few years. Usually I notice it was from chicks I helped out of the shell also. I don't help any chicks that seem "stuck" anymore either. Which may of helped also, I agree with Mike as well. If I know for sure which one throws it into the crockpot they must go.
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Were they both from the same hatch? Don swears it's an incubation problem, which would go along with the observation about assisted hatches. If you know which cock & hen they came from, and still have them paired up, I'd keep a close watch and see if you get any more. If you don't, I'd suspect something went wrong during incubation. If they keep popping up, then it might be the parents. I usually see 1 or 2 a year, usually in the buffs but occasionally in lavender, too. Knock on wood, so far none this year.
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I did see it on one LF silver chick this year and a customer said she had a LF silver chick or more from me that developed a crossed beak.
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I know it is more than an incubation problem, because I hatch about a dozen different breeds and varieties in the same incubator at the same time. Some lines are more prone to crossbeak than others. Some I have never had a crossbeak appear over a period of many years.
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I also doubt it's An incubation related problem I am leaning more towards genetics more so when line breeding. I say this because I have had 2 Blue LF chicks (out of 75) have it this year and I know the pen it came from is a Father to Daughter cross where I am trying to lock in the lacing. I have never had a problem with the Blues before this year. I also noticed when each bird both Cock and Pullet are bred in different matings I don't get any with cross beak. Which to me tells me it is definitely a recessive gene of some sort. I will be keeping both birds to test mate all breeders next year and try to eliminate it if possible without losing the extraordinary lacing I have achieved. Thankfully I toe punch all matings faithfully and keep records 😀
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Some lines have a propensity for this showing up, more than others. With some lines you seldom if ever see it occur. Wheaten bantams used to be quite bad for it, but I don't think so much any more. Select for short, stout beaks and I believe you can breed it out of a line with enough time and effort.
Another thing you can do is check the shape of the beaks. If the top mandible is curved and the lower one is straight, that is not good. Especially if it leaves a gap so you can see daylight between them from one side to the other. Stay away from parrot beaks too.
I found this very helpful Mike. I too had several cross beak chicks this year over previous years with my LF WBS. I went out and looked and some of my breeding stock have exactly what you describe above; curved upper and straight lower beaks with a slight gap! I know to cull for this now - thanks
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:)
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Wow, I have a few busy weeks with no time to check the forum and come back to a thread full of answers!
Beth- I do know which two birds they came from as I had them specifically paired together. The two chicks I got were from separate hatches, but same parents.
I also had another chick that was severely crossbeaked from completely different parents, that was so severe, I culled it rather than allowing it to hatch (I had intended to assist it as it was a late-hatcher and a desired chick for a project).
My husband won't let me put-down the crossbeak chicks (he's a real softy at heart), so I'm really not sure what to do with them... I had a "chicken rescue" that was going to pick them up, but she's not responding to my emails. If anyone has suggestions, I'm all ears.
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Tell your husband to "man up." They're chickens, not children. Life is terminal. And looking back, short. Choose to spend your time and other resources wisely.
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My thoughts precisely, Mike.
Hopefully he'll come around sooner than later.
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Michelle, I have an unrelated male you can have if we can figure out logistics. I have a friend with a grandbaby in Greensboro, if I can catch her when she goes up.
Tell your husband to "man up." They're chickens, not children. Life is terminal. And looking back, short. Choose to spend your time and other resources wisely.
This made me laugh out loud, especially "life is terminal!" If it makes him feel any better, I've tried to grow out a couple and they usually end up dying anyway, and you can provide a gentler death than nature will.
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This was posted on a FB forum:
Sigrid Van Dort has a section on crossed beak in the book "Genetics of the Chicken Extremes". There are two types of cross beaks, those that occur at hatch and those that occur weeks after hatch. The latter is the inheritable trait, however it is stated that this is from a recessive gene, but it is not complete. Because on testing, no one was able to produce pure breeding crossed beak birds, even after being heavily inbred. The conclusion was if the rest of the bird is good, do not hesitate to use it to breed because the chance of getting more are small. Now the ones that occur at hatch, that can be caused by a short high incubator temperature. The author did not state how high is high.
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I don't agree with Ms Van Dort that cross beaked birds should be used for breeding. If it is genetic, why would you want to perpetuate that in a line? I still think it is two recessives working together to produce the crossbeak, and the one does not necessarily have to be homozygous. That would explain why they could not produce a line that produce all crossed beaks.
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Cross beaks that occur at hatch are very rare in my experience, but with my last hatch the other day I did have a buff bantam with a cross beak. I don't believe it had anything to do with the incubator, in this case, due to the many hundreds of chicks that hatched, without cross beaks, under the same conditions. That is not to say that it is never caused by incubation problems.
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I'd have to agree with Mike but for one exception and this is if I had NO other choice. This one seems to be a no-brainer to me. Can't see one good reason to even have crossbeak genetics being perpetuated. I suppose if I had a flock that had been closed for several decades and I lost all my roosters except for a crossbeak, then I'd probably use him because I'd see that as better than bringing in who knows what by going outside.
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I'd have to agree with Mike but for one exception and this is if I had NO other choice. This one seems to be a no-brainer to me. Can't see one good reason to even have crossbeak genetics being perpetuated. I suppose if I had a flock that had been closed for several decades and I lost all my roosters except for a crossbeak, then I'd probably use him because I'd see that as better than bringing in who knows what by going outside.
I've never bred from one, yet they still appear from time to time in some varieties after many years and even decades. I'm not saying a recessive gene isn't the problem, but I still lean toward a congenital disorder/birth defect.
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I don't understand how it could be genetic and not be able to produce a line of them when inbreeding them ???... I think I'll continue to cull..lots I don't understand about genetics!!
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Stan, as I explained, my theory is it that would take two or more genes working in concert to produce the crossed beak. One could be homozygous (pure), but the other(s) would have to be heterozygous (impure) to get those kind of results. If it were required that all the genes be pure, it would be a simple matter to produce a line that bred true for it. But if there was impurity involved as well as one gene that was pure (inherited from both parents), you could easily explain why they could not produce the true breeding line. Does the report say how many birds were produced in the effort? I just wonder how extensive the research actually was. Van Doort knows a lot, but she is not really a scientist.
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I have no idea Mike..I just reposted that from another site because I thought maybe it would help in this post...I have not seen the study myself...
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Out of 150 chicks hatched this year, I've had two crossbeaks so far. One developed around 2 wks old and was culled, and the other was discovered during an egg topsy right after hatch. That chick was unturned in the egg and likely would not have been able to turn or pip due to the deformity. I thought it was interesting, as I had never seen an unhatched one before.
I have the book the study was taken from, and would be more than happy to type out the whole article later tonight :) though there is no mention of numbers of birds used or anything like that. The studies were done by Landauer (1938 & 1956) and Hutt (1932) if that helps...
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Lee, I'll save ya the trouble if this is it... http://www.genetics.org/content/26/4/426.full.pdf
I haven't read it yet but I was thinking it might be time for some college kid whose still got nothing but time on his hands to do another in depth study since genetic technology has come so far these days.
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Thanks Royce. I'm not the fastest typer, so much appreciated. :P
Ya, I'm thinking the same thing. Genetic knowledge has really come aways since then. And yet, isn't it amazing how many old time breeders seemed to instinctually know some of these things, even if they didn't always understand why or how. Since becoming a chicken farmer, I've come to the conclusion breeding birds is both an art and a science, with a whole lotta dice rolling in between! ;D lol
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Stan, thanks for sharing that, & Royce, for posting the link. While I don't agree with Ms. Van Dort that crossed beak birds should be used for breeding (except under exceptional circumstances like Royce said), I definitely want to read this. When I don't have a wild giggling child ricocheting off the walls...
I'm not saying a recessive gene isn't the problem, but I still lean toward a congenital disorder/birth defect.
I lean that way, too - because of the randomness of it, something just went arwy in the chick's development. But then, what Michelle got in back to back hatches sounds like something genetic. And if these are the birds I think they are, the hen & cock are unrelated. ???
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Mike G wrote...
If that is correct, and you wanted to eliminate the problem altogether, you would not use any bird that threw crossed beaks
On a similar note, on Facebook this same thing came up, and I was told, that beaks are easier to fix than wattles or combs. Frankly I thought it the other way.
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The problem is not with eliminating from SOME of the offspring, but in eliminating it from an entire line of birds for good. I'm not sure anyone has accomplished that; it may have been done, but I haven't heard about it in the last 40 plus years of breeding. The wheaten bantams are about the best success story I know of, but I'm pretty sure it still lurks in the genetics of individual birds.
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The problem is not with eliminating from SOME of the offspring, but in eliminating it from an entire line of birds for good. I'm not sure anyone has accomplished that; it may have been done, but I haven't heard about it in the last 40 plus years of breeding. The wheaten bantams are about the best success story I know of, but I'm pretty sure it still lurks in the genetics of individual birds.
The best we can do may be to really study the beaks of individual birds, in hand, before putting them in a breeding pen. We all know we don't breed from birds with crossed beaks, but how close to being perfect are they? Mike mentioned about them closing properly and that is one check point. Proper length of both the upper and lower beaks is another. Curvature is not just something that happens horizontally and viewed from the side, but also view the beak straight on and check that it isn't curved to the left or right of the face (both upper and lower beaks together). Be critical when you can.
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^ Good advice John. Not all beaks are made the same, that is for sure. In fact, bearded and crested birds seem to be more prone to weak or ill fitting mandibles in general. And once the lower jaw goes wonky, the top is soon to follow. I've also seen curved beaks on adults that were so slight it's likely to be missed unless you're looking for it. Which is the exact reason I've added a ruler to my tool kit, and all beaks must pass the straight edge test before entering a breeding pen. I am very particular about heads, and nothing bugs me more than a bad head on a bird.
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I'm really impressed with all the information brought up here! I did see the post on FB, but nice to see it discussed here too.
Beth, the birds in question were the brown-red's sister and the smaller nice male (the one with wonky legs got attacked, and my friend sold my back-up, ugh!).
I've got a bunch of chicks I'm growing out, some of which are new, unrelated stock, so hopefully I'll have some good replacement males in there...
I'll go out tomorrow and inspect the adult and chick beaks to see if I can spot what you're talking about, John.
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Morley Jull in 1950 says that twisted beak was found to be a simple autosomal recessive gene. Hutt assigned it the symbol is "su" and felt that it was a symptom of microphlathmia, a congenital birth defect that can be chemically induced, which the Merck Manual agrees and cites as a major cause of the condition in poultry. See here. http://qurl.com/pldgs (http://qurl.com/pldgs)
Landauer described 4 types of crossbeaks
1) the first type is present in chicks that have one eye missing and the upper beak is deviant
2) upper or lower deformities that also have abnormal skulls. This is homozygous condition.
3) the beaks are normal at hatch but the crossbeak appears a month later.** this is most common according to Hutt
4) cross-beaks that are developmental either before or at hatch which Landauer found only in White leghorns or Leghorn crossbreds, though Jull questions that point.
Types 3 and 4 are totally hereditary and are recessive to a normal beak. If they are bred, they will produce progeny with normal beaks which has made tracing it difficult , as no statistical ratios were found in 1950, that could be easily replicated & verified. It was found in a French experiment by Mercier and Poisson in 1925, that if trimmed, the bird could live a normal life and not have crossbeaked progeny. But when the upper beak is normal and the lower is twisted, that bird has to be culled, as trimming will not suffice, as the tongue gets exposed and becomes hardened (cornified) with age and it will not be able to eat.
But there are lots of beak issues, short upper beaks, missing mandibles, short lower mandibles (half the length of the lower beak) and missing maxillae (the upper beak is absent). Also in the latter case the nasal bones were very small, so many of these die in shell, but not all. All of these other cases are also autosomal (non sex linked) recessive and totally lethal in the homzygous state. Beak issues happen a lot according to Prof Jull with Houdans (a crested breed).
~brownie
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I don't think I agree with Jull. If it is simply a single recessive, why wouldn't it be possible to produce a line that throws all cross beaks? And why do cross beaks and normal beaks come out of the same pair matings, even out of the same setting of eggs? (They do - I had a pair of buff bantams that did it this year). No, I think it has to be a little more complicated than that.
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Well your first question Mike, that was done and it didn't happen which Hutt mentions so it does make Jull's comment suspect.
the second comment about breeding pairs, is taken up by Hill in 2001 where he studied that and the relationship of the egg yolk weight, age of the breeders and the incubator. Hill did find a correlation early on in the incubation cycle but nothing later. Others who have replicated this, Wolanski (2003, 2006) & came to the same conclusion: there is a correlation early in the incubation cycle to the chick beak, (actually yolk length to beak) but we are talking really early, i.e. day 7. Here they they weighed them all against the metric of .057. Since reading this a while ago,I've tested my eggs at day 7 but I don't have cross beaks so I haven't found anything....and of course that metric may not be the same for Ameraucanas. You would need to weigh a lot of eggs at day 7 to get the proper weight -- something I am doing with Araucanas but not yet with any other breed I own.
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I would tend to agree with Mike. I'm not geneticist but, from what I do know, it is possible to get homozygous recessive genes. For example the Straight Comb birds. You know if you cross 2 SC birds you are going to get SC chicks. So why wouldn't that be the case with recessive crossbeak genes?
The other question I have is how was it determined in 1950 "to be a simple autosomal recessive gene"? Was the technology even available then?
Interestingly enough, I read a post on FB today from a local poultry group site that some gal got a chick that is a crossbeak and has NO eyes!
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It is possible to have the homozygous condition for any type of gene, which means one of that particular gene was inherited from each parent, so there is a set of two. The exception would be sex-linked genes, which are inherited only from the male parent in birds (just the opposite for mammals and humans), so the condition of that single gene in a female bird would be called hemizygous. While they did not have the laboratory techniques available 65 years ago that we have today, the general principles of Mendel's laws were well known. Jull would have made test matings to arrive at his conclusions, but I believe he interpreted the results in an oversimplified manner.
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Study on LOC426217 as a candidate gene for beak deformity in chicken (https://bmcgenet.biomedcentral.com/articles/10.1186/s12863-016-0353-x)
Conclusions
To the best of our knowledge, this is the first time that LOC426217 was studied as an important candidate gene for beak deformity in birds. The over-expression of LOC426217 may be the cause of beaks malformation...
Background
The beak is an external structure of birds, consisting of the upper and lower mandibles covered with a thin keratinized layer of epidermis [1]. It is used for many important activities such as feeding, drinking, fighting, and preening. In addition to striking morphological differences between species, beak deformities of different forms (noticeably elongated, crossed, bent at right angles) have been documented in many wild birds [2, 3, 4, 5, 6, 7]. Frequencies of 1 % to 3 % of beak deformity (normally a crossed beak) were found in various indigenous chickens of China, such as Beijing-You (BJY) (studied here), Silkies, Qingyuan Partridge, and Huxu Chickens. Chickens with deformed beaks have reduced feed intake and growth rate. Therefore, beak deformity represents an economic as well as an animal welfare problem in poultry industry. According to our observations in a BJY population, in the absence of known environmental factors contributing to the malformation, birds with deformed beaks present consistently in each generation and cannot be eliminated from a population simply on the basis of the phenotype. This indicated the genetic effects underlying this trait...
Validation and tissue expression profile
...The results showed that the expression of LOC426217 in the deformed beaks was significantly higher than that in the normal beaks, which was in great agreement with DGE analysis. The result of tissue expression profile also revealed that this gene was specifically expressed in beak tissue. LOC426217 is a member of the keratin family [24]. Keratin is a key gene family for maintaining normal cell morphology [16]. Variation of keratin structure can lead to beak deformity [25]. It is also an intermediate filament protein that has essential functions in maintaining the structural integrity of epidermis and its appendages [26], presumably including the beak. In addition, keratin is the main composition of the chicken beak. This may be the main reason for its high expression in beak tissue. According to our early observation of beak anatomy, the lower mandibles of the beaks were abnormal/asymmetry. It was reported that avian keratin disorder could result in gross over growth of the rhamphotheca [7]. The beak deformity caused by the excessive growth of one side of the lower mandibles maybe a result of abnormal high expression of LOC426217.
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So, John, what conclusions do you draw from this study? Did they identify what exactly would cause the overexpression of this gene as the likely causative agent in the variability of keratin? I have long believed it is two or more different genes, likely on different chromosomes, working in concert with one another that cause the abnormality. Or perhaps it could be something environmental along with the variable distribution of keratin?
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My understanding is they feel environment plays a role (without saying how) and other genes may be involved, but this keratin gene is the key player in deformed beaks. I don't remember them saying anything about it being a recessive or dominant gene and that in the Chinese chicken strain studied cross beaks show up. I don't know of anyone that would breed from a bird with an cross beak and they seem to say the problem can't be eliminated by selective breeding. If they mean obvious cross beaks (aka scissor beaks) I can agree, but I still believe the problem can be addressed by selecting against breeders with slightly curved beaks and even less than perfect ones. We know from experience that some breeds/varieties/strains are more or less likely to have crossed beaks.