Line Breeding Explained

[labsnlurchers 39]

There is NO difference breeding father to daughter or son to mother, the dam DOES NOT have more influence in the pups, its 50:50, half from the sperm and half from the egg.

 

each gene has 2 alleles, one from the dam one from the sire. there are dominant and recessive alleles and the recessive will only be expressed if it is homozygous For example if the bitch is black homozygous call it BB and the dog is brown homozygous call it bb, and black is dominant over brown then ALL the pups will be black hetrozygous which is bB, there will be NO chance of having a brown pup, if a dog is then bred back to his dam ALL the pups will be black some BB and some bB, if a bitch pup is bred back to the sire then some pups from the litter will be black bB BB and some will be brown bb. I have used colour as an example but its the same for EVERY GENE, heart murmurs, deafness, blindness etc etc.......

 

Line breeding is a lottery, the dam and sire of the original litter may be fine and not express any detremental traits in their phenotype (what they are like) but they may carry a allele for such a trait in their genotype that will be expressed if a pup is bred back to whichever parent carries the detremental gene, makes NO DIFFERENCE if its son over mother or father over daughter.......The closer the relation the higher the risk of dtremental taits being expressed.

 

you have to expect a % of litter wastage when line breeding and if you dont get any wastage you are lucky, aslong as you can accept that then go ahead and line breed, you wont be the first or the last to do it BUT if everyone did it then there would be a BIG problem for future generations as the gene pool would become vastly reduced and detremental traits would become more and more common

 

Edited October 22, 2008 by labsnlurchers

[gnasher16 30,121]

There is NO difference breeding father to daughter or son to mother, the dam DOES NOT have more influence in the pups, its 50:50, half from the sperm and half from the egg.

 

each gene has 2 alleles, one from the dam one from the sire. there are dominant and recessive alleles and the recessive will only be expressed if it is homozygous For example if the bitch is black homozygous call it bb and the dog is brown homozygous call it BB, and brown is dominant over black then ALL the pups will be brown hetrozygous which is bB, there will be NO chance of having a black pup, if a bitch is then bred back to her father ALL the pups will be brown some BB and some bB, if a dog pup is bred back to the dam then some pups from the litter will be brown bB BB and some will be black bb. I have used colour as an example but its the same for EVERY GENE, heart murmurs, deafness, blindness etc etc.......

 

Line breeding is a lottery, the dam and sire of the original litter may be fine and not express any detremental traits in their phenotype (what they are like) but they may carry a allele for such a trait in their genotype that will be expressed if a pup is bred back to whichever parent carries the detremental gene, makes NO DIFFERENCE if its son over mother or father over daughter.......The closer the relation the higher the risk of dtremental taits being expressed.

 

you have to expect a % of litter wastage when line breeding and if you dont get any wastage you are lucky, aslong as you can accept that then go ahead and line breed, you wont be the first or the last to do it BUT if everyone did it then there would be a BIG problem for future generations as the gene pool would become vastly reduced and detremental traits would become more and more common

 

 

 

Anything to do with breeding gets my attention,what id ask you labslurcher, is are you stating your opinion or what you consider to be fact ?....one thing ive learned over many years learning myself and from others is that nature often makes light of what we think are facts.....i agree with most of what you say IN THEORY....but the truth is theory very rarely works in reality......i imagine your a very educated guy,either that or you have been reading too many science books ....i am not educated and the amount of books ive read i can count on one hand.....but what i do know is when it comes to nature what is learned in a classroom or from a book is often very different to the real world...for instance,yes that is right IN THEORY the influence both parents have over a litter of pups is 50/50.....BUT......in theory you can flick a coin 100 times and it should land 50 times on heads and 50 times on tails right ?....yet in the real world that rarely happens...i totally disagree what you say about linebreeding being a lottery....man has bred dogs to his own ideals for generations hence why we have so many different dog breeds to suit mans purpose for them....these didnt come from luck in a lottery,they came from selective breeding...why do you have to accept wasteage in litters if you are selective about the individuals you breed from....and how can every gene be the same unless you go along with the theory of genes and traits being one and the same which personally i do not....

If all these things are your opinion then so be it we all differ with our understandings....but to try to present these as facts just because they are written down i feel with respect is misguiding people.

[Clover 0]

Anything to do with breeding gets my attention,what id ask you labslurcher, is are you stating your opinion or what you consider to be fact ?....one thing ive learned over many years learning myself and from others is that nature often makes light of what we think are facts.....i agree with most of what you say IN THEORY....but the truth is theory very rarely works in reality......i imagine your a very educated guy,either that or you have been reading too many science books ....i am not educated and the amount of books ive read i can count on one hand.....but what i do know is when it comes to nature what is learned in a classroom or from a book is often very different to the real world...for instance,yes that is right IN THEORY the influence both parents have over a litter of pups is 50/50.....BUT......in theory you can flick a coin 100 times and it should land 50 times on heads and 50 times on tails right ?....yet in the real world that rarely happens...i totally disagree what you say about linebreeding being a lottery....man has bred dogs to his own ideals for generations hence why we have so many different dog breeds to suit mans purpose for them....these didnt come from luck in a lottery,they came from selective breeding...why do you have to accept wasteage in litters if you are selective about the individuals you breed from....and how can every gene be the same unless you go along with the theory of genes and traits being one and the same which personally i do not....

If all these things are your opinion then so be it we all differ with our understandings....but to try to present these as facts just because they are written down i feel with respect is misguiding people.

 

 

Hi Gnasher

 

I think you've misunderstood what the OP said when he said Line Breeding is a lottery. What he meant was that you are possibly increasing your risk of ending up with pups which show a problem - IF the problem is something caused by 2 recessive genes, as you've increased your likelihood of producing a pup which carries the two recessive genes. . However - the problem has to be there in the first place and your closely bred dogs might not carry any nasties.

 

What he has said is quite correct in theory (but I thought black was usually dominant over brown - it is in my breeds?) - but as you've said, when it comes to an actual litter you don't always get the expected results in terms of percentages showing expected colours etc . Dogs don't read text books

[labsnlurchers 39]

There is NO difference breeding father to daughter or son to mother, the dam DOES NOT have more influence in the pups, its 50:50, half from the sperm and half from the egg.

 

each gene has 2 alleles, one from the dam one from the sire. there are dominant and recessive alleles and the recessive will only be expressed if it is homozygous For example if the bitch is black homozygous call it bb and the dog is brown homozygous call it BB, and brown is dominant over black then ALL the pups will be brown hetrozygous which is bB, there will be NO chance of having a black pup, if a bitch is then bred back to her father ALL the pups will be brown some BB and some bB, if a dog pup is bred back to the dam then some pups from the litter will be brown bB BB and some will be black bb. I have used colour as an example but its the same for EVERY GENE, heart murmurs, deafness, blindness etc etc.......

 

Line breeding is a lottery, the dam and sire of the original litter may be fine and not express any detremental traits in their phenotype (what they are like) but they may carry a allele for such a trait in their genotype that will be expressed if a pup is bred back to whichever parent carries the detremental gene, makes NO DIFFERENCE if its son over mother or father over daughter.......The closer the relation the higher the risk of dtremental taits being expressed.

 

you have to expect a % of litter wastage when line breeding and if you dont get any wastage you are lucky, aslong as you can accept that then go ahead and line breed, you wont be the first or the last to do it BUT if everyone did it then there would be a BIG problem for future generations as the gene pool would become vastly reduced and detremental traits would become more and more common

 

 

 

Anything to do with breeding gets my attention,what id ask you labslurcher, is are you stating your opinion or what you consider to be fact ?....one thing ive learned over many years learning myself and from others is that nature often makes light of what we think are facts.....i agree with most of what you say IN THEORY....but the truth is theory very rarely works in reality......i imagine your a very educated guy,either that or you have been reading too many science books ....i am not educated and the amount of books ive read i can count on one hand.....but what i do know is when it comes to nature what is learned in a classroom or from a book is often very different to the real world...for instance,yes that is right IN THEORY the influence both parents have over a litter of pups is 50/50.....BUT......in theory you can flick a coin 100 times and it should land 50 times on heads and 50 times on tails right ?....yet in the real world that rarely happens...i totally disagree what you say about linebreeding being a lottery....man has bred dogs to his own ideals for generations hence why we have so many different dog breeds to suit mans purpose for them....these didnt come from luck in a lottery,they came from selective breeding...why do you have to accept wasteage in litters if you are selective about the individuals you breed from....and how can every gene be the same unless you go along with the theory of genes and traits being one and the same which personally i do not....

If all these things are your opinion then so be it we all differ with our understandings....but to try to present these as facts just because they are written down i feel with respect is misguiding people.

 

In the dog, there are 78 chromosomes existing of 39 matched pairs which make up the dog’s “genotypeâ€. On the other hand, the dog’s “phenotype†is what the animal actually looks like and this can be influenced by both environmental and developmental factors. For example, a dog’s adult size is partially determined by his genotype but is also influenced by such factors as health and nutrition as a puppy.

 

Chromosomes are found in pairs and each gene on a given chromosome has a partner at the same position on the matching chromosome. Each member of this gene pair is called an allele and each allele pair influences a particular trait. If the two alleles are the same, they are “homozygousâ€. If they are different, they are “heterozygousâ€.

 

Everything i have stated is FACT that is derived from years and years of practical (real world) genetic researching and a Bsc (hons) Animal Science.

Exactly, you got it in one, its like flipping a coin, there is NO way of telling before hand whether it will land on heads or tails same as there is no way of telling (without expensive dna profiling and genotyping) whether the dam or sire will be dominant in the offspring. A dominant allele will 'override' a recessive allele. 50% of the pups genes are from the dam and 50% from the sire but the 'flipping of the coin' comes in when considering which will be expressed in the resulting offspring.

 

Selective Breeding.....This is undertaken after considering the phenotype of the proposed dam and sire, as far as i am aware there is no consideration given to the individuals genotype which may harbour a recessive allele as part of a heterozygous gene in which case it will not be expressed in the phenotype of the animal in question but has the potential to be expressed in offspring if a homozygous situation arises which is increasingly likely in linebreeding.

 

When line breeding you have to accept the potential for litter wastage because unless you know the genotype of the dam and sire there is potential for a detremental trait to be expressed if a homozygous situation arises in any of the progeny.

 

Genes and traits are not 'one and the same'

Genes dictate which traits are expressed in the phenotype of the animal.

 

I have found a website that may explain it better than i have

http://spear-barkennels.com/Genetics.php

 

Edited October 22, 2008 by labsnlurchers

[labsnlurchers 39]

you are correct clover, thanks for pointing it out, i had a few jars before posting lastnight thats my excuse anyway lol!

Ive corrected it so people dont breed black with brown and expect brown cheers

[Guest smashygadge]

very intresting stuff labsanlurchers .

iam not going to go into anymore detail as i couldnt .

what i do think and find with alot of line breeding if its right for you .

its a good route to take obviously you do get good and some bad occasionaly.

that can happen anywhere in any breed.

i think line breeding is good for a man who is happy with certain traits he wants to keep.

and i think why not .and a really nice thread very explanitory ,intresting

[gnasher16 30,121]

With respect...you havent told me anything i havent already read myself....and i did say READ because thats all it is a read.....i say again,the real life results of breeding dogs can and is very different from what the text books say......all the long words in the world wont change that.....there are literally thousands of examples to put all that theory to ruin happening every day....yes of course there are breeding ideals and scientific fact...but nature behaves how it wants to sometimes all we can do is give it a helping hand by putting the odds in our favour.....

I have shared views and opinions with some of the better breeders in the world of the particular breed that interests me and none were professors scientists or what would be considered educated people,well maybe one or two but nothing to write home about ......their thoughts along with mine were gained by doing it and learning from the good and bad not reading how it should be done,dont get me wrong,i think anybody breeding dogs seriously needs a basic understanding of genetic principals....but when it comes to scientific jargon it simply doesnt hold as much weight in real life as you may think.

ok you talk of detrimental traits within linebreeding and how these traits may crop up.....but what about desirable traits....if you can avoid bad traits that are underlying you can also bring good ones out....and this is where the selection process is so important....nobody breeds 100 per cent perfect dogs all the time,all lines or strains carry both desirable and undesirable traits.....its just about the selection process and basic genetic understanding of putting the odds in your favour whether the good or bad comes out in offspring and how strong it comes out....some pure family dogs are bred for many generations within the same family both inbred and linebred without bad traits coming out....

If anything is a lottery it is breeding 2 unrelated dogs as you have so much more variances within the genes,the closer the breeding the less variance within the genes the more you can predict whats coming the less like a lottery it is....a bad trait will only come out when it repeats on another bad trait,depending how heavy within the parentage that trait is it might stand a 1 in a million chance of actually repeating and surfacing.....then again a good or bad gene that is being carried in a heavier doseage naturally has much more chance of repeating and surfacing,hence again why the selection process within related individuals is ultra important the tighter you go with your breeding....breeding unrelated dogs is definately the genetic lottery which is the basic reason your average crossbred mutt is a far healthier individual animal than your purebred line or inbred dog,there is just less chance of genes good or bad repeating on each other.

I respect all the science and medical research in the world but i believe hands on doing it over many years teaches you a lot more about the realities of it....all the best

[labsnlurchers 39]

Smashygadge you are right, a detremental trait can be expressed in any offspring of any breeding, in that sense breeding as a whole is one great big lottery. The risk you take when line breeding is increased somewhat because the gene pool is reduced.

Example Apple trees! lol

If you have 1 apple tree with 10 apples on it and 1 of the 10 is bad. You close your eyes and pick one then you have a 1 in 10 chance of picking a bad apple

If you add 9 more apple trees with 10 healthy apples on each then close your eyes and pick an apple you have a 1 in 100 chance of picking a bad apple

Now think of the apple trees as a bloodlines and the bad apple as a detremental trait..... even without linebreeding there is still a chance of a 'bad apple' but the risk of it is reduced.

 

you are also correct in saying it is a way of keeping your desired bloodline and not diluting it with others and i dont think there is anything wrong with doing it as long as you are prepared for the potential problems that may arise

Edited October 22, 2008 by labsnlurchers

[gnasher16 30,121]

Thats exactly my point.....see we was in agreement all along like i said,it cant be stressed enough how important the selection process is when breeding related dogs....we only select dogs for breeding who we consider to have picked up good traits,and not picked up bad....this doesnt matter when the dogs have no common ancestry because how can genes repeat if they are not shared.

The trees example was good,but remember that also works the same for desirable traits as well whether you use inbred or linebred individuals to shape your bloodline....they are both to be used as tools....selection is everything....

Nice to hear your thoughts

[Clover 0]

"Selective Breeding.....This is undertaken after considering the phenotype of the proposed dam and sire, as far as i am aware there is no consideration given to the individuals genotype which may harbour a recessive allele as part of a heterozygous gene in which case it will not be expressed in the phenotype of the animal in question but has the potential to be expressed in offspring if a homozygous situation arises which is increasingly likely in linebreeding."

 

Can I take issue with you here, Labsnlurchers. As a responsible and knowledgeable breeder, I do take into account the possible genotype of the dogs that I breed from, not just their phenotype, because I do research into their ancestors and relatives (in fact, after over 20 years in my breed, I personally knew a lot of dogs in pedigrees and have talked to knowledgeable breeders about the dogs that were about before my time) and also into the pups that potential studs have produced - I then have a lot more idea about what they are potentially carrying. Unfortunately, it seems to me that responsible and knowledgeable dog breeders are in the minority.

[victor 10]

thank you for that

[labsnlurchers 39]

"Selective Breeding.....This is undertaken after considering the phenotype of the proposed dam and sire, as far as i am aware there is no consideration given to the individuals genotype which may harbour a recessive allele as part of a heterozygous gene in which case it will not be expressed in the phenotype of the animal in question but has the potential to be expressed in offspring if a homozygous situation arises which is increasingly likely in linebreeding."

 

Can I take issue with you here, Labsnlurchers. As a responsible and knowledgeable breeder, I do take into account the possible genotype of the dogs that I breed from, not just their phenotype, because I do research into their ancestors and relatives (in fact, after over 20 years in my breed, I personally knew a lot of dogs in pedigrees and have talked to knowledgeable breeders about the dogs that were about before my time) and also into the pups that potential studs have produced - I then have a lot more idea about what they are potentially carrying. Unfortunately, it seems to me that responsible and knowledgeable dog breeders are in the minority.

 

Apologies, i shouldnt have said there is no consideration to genotype because as you say, researching a bloodline ancestory provides an insight into any potential problem genes that the dog/bitch may be harbouring but not expressing as it is highly likely that it would have been expressed at some point down the line (highly likely but not 100%). I agree that responsible and knowledgeable dog breeders are in the minority, they are not none existant, apologies.

[labsnlurchers 39]

Thats exactly my point.....see we was in agreement all along like i said,it cant be stressed enough how important the selection process is when breeding related dogs....we only select dogs for breeding who we consider to have picked up good traits,and not picked up bad....this doesnt matter when the dogs have no common ancestry because how can genes repeat if they are not shared.

The trees example was good,but remember that also works the same for desirable traits as well whether you use inbred or linebred individuals to shape your bloodline....they are both to be used as tools....selection is everything....

Nice to hear your thoughts

 

i agree selection is everything but not only in line breeding, breeding in general requires careful selection because even in a situation where the dam and sire are not related there is still a potential for a recessive gene responsible for certain abnormalities/detremaental traits associated with a certain breed to be carried by both and expressed in offspring from that mating.

[Funfuret 1]

each gene has 2 alleles, one from the dam one from the sire. there are dominant and recessive alleles and the recessive will only be expressed if it is homozygous For example if the bitch is black homozygous call it BB and the dog is brown homozygous call it bb, and black is dominant over brown then ALL the pups will be black hetrozygous which is bB, there will be NO chance of having a brown pup, if a dog is then bred back to his dam ALL the pups will be black some BB and some bB, if a bitch pup is bred back to the sire then some pups from the litter will be black bB BB and some will be brown bb. I have used colour as an example but its the same for EVERY GENE, heart murmurs, deafness, blindness etc etc.......

 

It would be good if all genes were as simple as that but Mendel was considered lucky to have hit on genes that just showed simple/complete dominance. There are also genes that are codominant, and genes that express incomplete dominance. Added to that, most genetic traits are controlled by multiples sets of genes each with their own dominance relationships and little is understood about some, if not many, of the genes.

 

Add in the random mutations that occur, and it seems self evident to me that trying to breed for complex genetic traits such as hardiness or working ability is akin to doing a lucky dip.

[labsnlurchers 39]

each gene has 2 alleles, one from the dam one from the sire. there are dominant and recessive alleles and the recessive will only be expressed if it is homozygous For example if the bitch is black homozygous call it BB and the dog is brown homozygous call it bb, and black is dominant over brown then ALL the pups will be black hetrozygous which is bB, there will be NO chance of having a brown pup, if a dog is then bred back to his dam ALL the pups will be black some BB and some bB, if a bitch pup is bred back to the sire then some pups from the litter will be black bB BB and some will be brown bb. I have used colour as an example but its the same for EVERY GENE, heart murmurs, deafness, blindness etc etc.......

 

It would be good if all genes were as simple as that but Mendel was considered lucky to have hit on genes that just showed simple/complete dominance. There are also genes that are codominant, and genes that express incomplete dominance. Added to that, most genetic traits are controlled by multiples sets of genes each with their own dominance relationships and little is understood about some, if not many, of the genes.

 

Add in the random mutations that occur, and it seems self evident to me that trying to breed for complex genetic traits such as hardiness or working ability is akin to doing a lucky dip.

 

I was leaving co dominance etc for another day, gets a bit confusing for the average bloke.

Ill try and explain using an example of coat length.....

Long coat is codominant with short coat producing a medium coat so, a long coat must be LL homozygous, a short coat must be ll homozygous and Ll hetrozygous produces medium coat so neither L or l is dominant.

 

EXACTLY with codominance, incomplete dominance, random mutations etc etc it is a lottery but the more research you do into the origins of the line/family history etc then the higher the chance of getting what you want and avoiding what you dont want but it is NOT 100% and never will be imo.