Natural Bobtail Dna

[alpha bet]

Have been reading up on the Natural Bobtail gene (NBT) . My breed is the aussie shepherd but this also can be relevant to other breeds. thought I would post and see if others have any information that might help.

Theory is that if the pup in embryo ends up with the NBT gene from both parents (then classed as Affected) then that embryo will not survive and can be reabsorbed by the bitch. Were as the pup in embryo gets only one gene he will be Carrier hence this pup when born will carry the trait and have the shorter or bob tail. If the embryo doesnt receive the gene from either parent then the pup is Clear and born with a full tail.

This does seem to hold true as any results I have seen on DNA testing for aussies will show the dogs with shorter tails as Carrier I have never seen any paperwork showing Affected. so this would indicate that dogs Affected are never born.

I have a bitch who is NBT and she has had three litters all to males that I assume are also NBT - her litter sizes were 1st =4 2nd=4 3rd=1. These are very small litters and one thing I used to see was lots of Aussie Shepherds seemed to have smallish litters 4-6. However occassionally have seen bigger numbers such as my last litter of 9 puppies but in this case the mother is full tail and father is NBT.

My initial conculsion would be to but my NBT bitches only to males who are not - hence to get some better size litters.

Anyone else have any ideas.

[Bob]

Hi,

Just for argument sake let's call the normal tail gene F for full and the other NBT. Your possible combinations for two NBT dogs then would be FF, FNBT, FNBT and NBTNBT. If NBTNBT is a lethal combination then you are only going to get the other three combinations, FF = normal tail, FNBT = bobtail in both instances so you are likely to get litters 75% of the normal size with 33% normal tail and 66% NBT.

If you were to use a full tailed dog in your breeding programs to NBT you should get the usual litter numbers with 50% normal and 50% NBT.

Hope that helps.

Regards,

[alpha bet]

Thanks Bob, I understand the ratios - Just wondering if anyone else might be finding they have wondered why they have had smaller litters in some instances.

The research that I have found is with very limited numbers of litters and therefore inconclusive.

ps: Makes me more inclined to consider using my own full tailed black tri boy back into the program - especially as it seems difficult to find Black Tri Boys let alone any that have full tails (well at least any that admit to it)

Edited February 20, 2012 by alpha bet

[leopuppy04]

Hi alpha bet,

Have often wondered the same thing and like you - with limited information the results are inconclusive.

I have done 2 litters and for an Aussie both have been relatively small - 6 and 5. Both breedings are NBT x NBT and in the first litter I had 3 tails, 3 NBTs and in this one I have had 4 NBTs and 1 tail.

I do however (to throw a spanner in the works!) know of breeders who have done NBT x NBT and have ended up with a 'normal' sized litter. So I think it's really hard to find conclusive evidence.

I'm very big however on not choosing a dog because of it's tail length. that's throwing too much of our gene pool away. Like you, I kept a tail from my first litter, and this will allow me to breed to NBTs hopefully without reducing the litter size at all.

I think it's something that we need to research a little more, but hard to find information.

Keep in mind also that this is not a straight gene that is playing here (hence the different tail lengths). We often have to look into the modifiers affecting the tail lengths also. I honestly believe that this is where some breeders have a tailed dog that has come back genetically Affected, and others have an NBT that has come back 'clear'.

[Tenties]

One must'nt forget the Rumpy , that is a puppy born with no tail, some puppies from 2 NBT Parents can be born with incomplete spines lack of Anus etc, ive never had any probs with the NBT gene and all but one of my dogs are NBT i firmly believe those dogs that have had problems with the NBT gene have come down from breeds who dont actually have the gene in there history i think in the cases where it has shown up in some non traditional docked breeds and mistaken for the NBT gene it is an actual fault and therefore causes problems for the affected dog down the track ???

[alpha bet]

Hi alpha bet,

Have often wondered the same thing and like you - with limited information the results are inconclusive.

I have done 2 litters and for an Aussie both have been relatively small - 6 and 5. Both breedings are NBT x NBT and in the first litter I had 3 tails, 3 NBTs and in this one I have had 4 NBTs and 1 tail.

I do however (to throw a spanner in the works!) know of breeders who have done NBT x NBT and have ended up with a 'normal' sized litter. So I think it's really hard to find conclusive evidence.

Three questions,

When you say NBT x NBT getting normal sized litters, were they DNA tested as NBT Carrier - otherwise it could just be that some of these dogs were actually tailed dogs who were docked ? For example most of the imports from USA could easily be full tailed dogs - and i do find it somewhat a strange coincidence that soooo many full bob dogs happen to be in the shows....?

Is a half tail or 3/4 tail still considered a NBT ?

Have you seen any DNA results of a dog showing as NBT Affected ? (I have only seen NBT Carrier, even with a few being dogs with virtually bobs)

Edited February 21, 2012 by alpha bet

[leopuppy04]

Hi alpha bet,

Have often wondered the same thing and like you - with limited information the results are inconclusive.

I have done 2 litters and for an Aussie both have been relatively small - 6 and 5. Both breedings are NBT x NBT and in the first litter I had 3 tails, 3 NBTs and in this one I have had 4 NBTs and 1 tail.

I do however (to throw a spanner in the works!) know of breeders who have done NBT x NBT and have ended up with a 'normal' sized litter. So I think it's really hard to find conclusive evidence.

Three questions,

When you say NBT x NBT getting normal sized litters, were they DNA tested as NBT Carrier - otherwise it could just be that some of these dogs were actually tailed dogs who were docked ? For example most of the imports from USA could easily be full tailed dogs - and i do find it somewhat a strange coincidence that soooo many full bob dogs happen to be in the shows....?

Is a half tail or 3/4 tail still considered a NBT ?

Have you seen any DNA results of a dog showing as NBT Affected ? (I have only seen NBT Carrier, even with a few being dogs with virtually bobs)

Yes, I have known of litters (rare, but it happens) where both parents are KNOWN to be NBTs. I have heard of at least one litter, some years ago of 11 puppies and 100% of them were NBTs.

Any length of bob is still 'genetically' considered a NBT. It's modifiers that affect the length of the tail.

I've never looked into doing the DNA testing. Not enough Aussie breeders do it and frankly IMO I'm not convinced that the testing is 100% accurate. Until they stop getting false positives/ false negatives, I'm not going to be doing the DNA tests.

[asal]

Hi alpha bet,

Have often wondered the same thing and like you - with limited information the results are inconclusive.

I have done 2 litters and for an Aussie both have been relatively small - 6 and 5. Both breedings are NBT x NBT and in the first litter I had 3 tails, 3 NBTs and in this one I have had 4 NBTs and 1 tail.

I do however (to throw a spanner in the works!) know of breeders who have done NBT x NBT and have ended up with a 'normal' sized litter. So I think it's really hard to find conclusive evidence.

Three questions,

When you say NBT x NBT getting normal sized litters, were they DNA tested as NBT Carrier - otherwise it could just be that some of these dogs were actually tailed dogs who were docked ? For example most of the imports from USA could easily be full tailed dogs - and i do find it somewhat a strange coincidence that soooo many full bob dogs happen to be in the shows....?

Is a half tail or 3/4 tail still considered a NBT ?

Have you seen any DNA results of a dog showing as NBT Affected ? (I have only seen NBT Carrier, even with a few being dogs with virtually bobs)

in australia there is the stumpy tailed cattledog AND what is referred to as the tomahawk stumpy.....(removed by tomahawk/axe)

remember folks when you are dealing with a x or y gene...have NBT gene, short tail. dont have NBT gene, long tail. (do i have it right ?)

same percentages as for the sex gene...n guess what? ive had litters of 7 and 8 ALL THE ONE SEX.

so if the NBT is in both dogs , NBT/clear to NBT/clear and NBT/NBT is lethal as suspected you can get no puppies at all or none with NBT eg all tailed puppies, either every conception is a SEPERATE THROW OF THE DICE..

HAVE TO KEEP remembering that folks.

so you have "tomahawk's" in the aussie shepherds too then :laugh:

Edited February 22, 2012 by asal

[poocow]

asal - it is not a simple mode of inheritence for nbt - its not just one gene, there are modifying factors in play as well.

A nbt for Aussies is anything that is not a full length tail - so anything up to 1 less vertebrate than a full tail.

[asal]

asal - it is not a simple mode of inheritence for nbt - its not just one gene, there are modifying factors in play as well.

A nbt for Aussies is anything that is not a full length tail - so anything up to 1 less vertebrate than a full tail.

thanks,, then it confuses things even more when a metal "gene" like the tomahawk is in some mixes too?

[Kia]

the NBT trait does have modifiers that make it dificult to predict what you might get.

To date I have done full tailed to full tailed which resulted in litters of full tailed and ended up with my smallest litter of 7.

NBT to full tailed has produced several litters of 8 of which I have had a length from not even 2" as an adult to one who was missing 1 digit.

I am currently awaiting my first litter of NBT x NBT.

The Americans have done generations of NBT x NBT with some very large litters. While there are some issues that may turn up they also turn up in full tailed breeds so not related to the NBT gene.

Size of litter can often be due to the pedigree ..... some lines produce small litters.

I should add that it can be difficult to tell if a dog is missing 1 digit. Some dogs also appear to have longer bones in the tail compared to others.

Edited February 23, 2012 by Kia

[alpha bet]

Thanks for further comments.

I am going to keep my eye on litter numbers where possible, see if i can get a better idea. Ive had all my breeding dogs tested for NBT (just out of curiosity) The Full tails have come back with Clear, the shorter tails have come back Carrier, the bob tail has also come back as Carrier. None come back as Affected - so until I see paperwork otherwise perhaps I have to conclude that any Affected would not be born.

The research I have found from States is unclear as the number of litters used was limited and therefore considered inconclusive. Plus difficult with the States as they dock and there is no way of knowing with most. Same does seem to apply here with not that many doing the NBT DNA. shame really would be good for the long term.

Anyone out there wanting to share info I am happy to oblige.

Currently looking for a NBT-Clear solid coloured male to put to a NBT Carrier female..... anyone know of a good one.... prefer vic or sa or tas