Please can I have your thoughts on mating half brother to half sister (share the same dam but different sire)

Is this line breeding?

We were going to do it, same dams, only thing that stoped it was the dog got PPC.

Yep I would do it if the shared parent is an outcross as it is the best way of finding out what the shared parent has contributed in good and bad traits.

I do prefer though to use a parents half sibling on the others offspring.

>Is this line breeding?

No, this is inbreeding, and is only to be done if you're prepared to destroy the whole litter if it goes wrong.

The difference between line breeding and inbreeding is only semantics and is largely about degree. 

Some sources would not consider half sibling matings inbreeding reserving that tag for full sibling, parent offspring and grandparent to grandoffspring matings.

This mating has been used very successsfully in my breed, thugh less commonly these days with our shrinking numbers.

Mike Stockman (a good name for someone in his position! :D), writing in 'Veterinary Notes for dog owners' defines in-breeding as being "the mating of close relatives, such as grandfather to grand-daughter, half brother to half sister." and line-breeding as using dogs with common ancestors three or four generations back. He points out that experienced breeders are well aware of the possible dangers of in-breeding and that it should not be practiced by the inexperienced.

There are very good definitions here.

I think if it's done occasionally it's a good thing.  Problems arise when it's done constantly down through the pedigree.

Debs

I have always been advised it is something that should only be done every few generations especially if a lot of out cross blood has been used, and of course only if you are trying to fix traits from a dog or bitch that have been producing something special and good health and vigour.

>> I think if it's done occasionally it's a good thing.  Problems arise when it's done constantly down through the pedigree

I personally do not disapprove of inbreeding/close line breeding as long as the breeder is experienced and knows the line inside out (including what problems may occur). Most people line breed to fix a particular trait. Unfortunately I have seen some matings recently which are exactly as described above (half sibling matings) where one is known to carry (or rather produces) a genetic fault!!

No, this is inbreeding, and is only to be done if you're prepared to destroy the whole litter if it goes wrong.


Ditto 100%. People do it all the time I personally think it is too close.     I think that doubling up like that makes for more problems down the line also. Things not visible in the first 6 months that then can affect future generations.

I personally believe that you can achieve type by mating dogs that are similar types, not just in the 1st generation but of dogs that are similar types for 2-3 generations. The gene pool is wider and less potentional problems.  Just my opinion :-)

It's been done many, many times in my breed. My own stud dogs have been mated to bitches with the same sires.  All the (1/2 brother x sister) litters I know off produced something that done well in the ring and several champions have this sort of breeding behind them. I would call it line breeding, or solidifying a line.

I've never heard of a litter needing to be culled JG because it all went wrong ??

edited to say of course as with nay line /in breeding you do need to have a comprehensive knowledge of all the dogs behind the sire and dam :)

My one and only litter was the result of a half sibling mating. It was done under the close supervision of the top breeder in the breed, so I was confident that it was not going to be any sort of catastrophy. I wouldn't call it inbreeding because although the two parents shared the same sire, their dams were completely unrelated.

Dawn R.

My mentor (very well-respected in the breed) from years back worked by the rule of thumb that if such a pairing was illegal in humans then it was inbreeding. :) Marrying your cousin is legal, so that would be line-breeding. Marrying your half-sibling isn't legal, so would be inbreeding. Makes it much easier to understand. :)

The actual closeness of the relationship in terms of blood is the same for both those pariings though so human morality has nothing to do with it really.

Full First cousins will share 50% of the same bloodlines, so do half siblings, in the one case it is two individuals (grandparents) in common and in the latter one parent in common.

Human morality prevents half siblings marrying and in soem cultures even first cousins are a no no.

No, first cousins have no parents in common - the link is a generation back.

they have two grandparents in common so the percentage of shared blood is the same.  Half siblings have a shared parent do 50% same blood.  Cousins have two grandparetns in common each is 25% of their bloodline so again 50% same bloodlines.

know off produced something that done well in the ring and several champions have this sort of breeding behind them. I would call it line breeding, or solidifying a line.


It is definately not line breeding. A half sister and brother is without doubt inbreeding.

http://www.canine-genetics.com/relation.htm

People now have more understanding about genetics and how calculating the coefficients of dogs can help get what they want without doubling up too much.

Generally speaking or my understanding a dog over 12.5% has a good chance of reproducing himself in type.  Know it isn't just as cut and dry as that but some of the tools are very good..

The article actually says there is no disticntion any mating of related animals is inbreedign, people just disagree over the degree they choose to label as inbreeding and line breeding.  Hlf sibs woudl give you 12.5% inbreeding coefficent from what I understand of the article.

Depends how you read it :-) .. Sorry if I confused ,  the reason I posted it was to show that if you use the inbreeding coefficients generally my understanding is  12.5% and above is generally where we go from line breeding to inbreeding.

That was the 1st link I found. I have a couple good ones on my home PC but using my laptop just now.

Half siblings is 12.5% and is as close as I woudl go if I had outcrossed previously.

Generally speaking or my understanding a dog over 12.5% has a good chance of reproducing himself in type.  Know it isn't just as cut and dry as that but some of the tools are very good..

Sorry I wrote that completely wrong.  The way I worded that made it sound like I meant it in a postive way, I didn't :-)  I meant that in my opinion a dog of 12.5% and over has a good chance of reproducing himself and every bad thing along with it, including health problems including all the hidden genes that carries carry where it is then very difficult to pin point the dog due to the multiple appearance of so many..

in breeding you do need to have a comprehensive knowledge

That's the problem for me because I don't think you can have enough knowledge personally ..

You don't know who is carriers for health problems there are no tests for and some health problems are polygenetic.

What's that old saying 'Twice in, once out' and IMO, yes to use fresh line occasionally is recommended but to achieve type you need to closer breed.  If Curtis had been Mia's half brother instead of full brother I would've had no hesitation in mating her to him and carrying on basically knowing what type I would get with the litter.  

My first litter was 2 dogs that had basically nothing in common with one another and the pups could be paired for type eg. 2 roans that looked similar, 2 very white pups that looked similar but having gone 'in' with the next generation, the same type & markings were consistent across the litter.

Personally I feel the quality of pedigree animals is falling because people are just keen to use the latest champion or nearest dog and have no understanding of the basic elements of animal husbandry & conformation.

What's that old saying 'Twice in, once out' and IMO, yes to use fresh line occasionally is recommended but to achieve type you need to closer breed.  If Curtis had been Mia's half brother instead of full brother I would've had no hesitation in mating her to him and carrying on basically knowing what type I would get with the litter. 

Hi Christine, 

I don't think we are talking about fresh blood here :-)  " A fresh line" would be an outcross. That is a 3rd variable to the conversation/thread I think.

There is no 100% guarantee Christine that close matings produce type or quality.   I think it is shetland sheep dogs they are finding the it to work the opposite just now. ( will confirm that when I find the article :-) )  I agree some breeds for various reason maybe have had to due to gene pool issues etc but linebreeding to type (under 12.5% inbreeding) can and is as successful as inbreeding if not more successful in the long term. IMHO.

My first litter was 2 dogs that had basically nothing in common with one another and the pups could be paired for type eg. 2 roans that looked similar, 2 very white pups that looked similar but having gone 'in' with the next generation, the same type & markings were consistent across the litter.

When I personally refer to type, colour is never a factor.   Type to me is construction even in breeds where various colours are acceptable.  If you put 6 puppies in front of me and ask me to put them into type colour would  never be the group decider.

What does " twice in and once out"  mean :-) ?   Does it mean inbreeding for 2 and line breeding for 1  or  line breeding for 2 and an outcross altogether for 1.. :-)     in my book that is 2 totally different senarios one would be acceptable to me and the other not..


You can achieve type by type breeding, you can achieve type by line breeding and you can acheive type by inbreeding. You can also not get type with all three and lose quality with all three also.

Personally I feel the quality of pedigree animals is falling because people are just keen to use the latest champion or nearest dog and have no understanding of the basic elements of animal husbandry & conformation.  I totally agree with you on that one but I don't think it would be arguement for inbreeding over line breeding in my book  :-D

I think the biggest proof that line/in-breeding, call it what you want, is successful and establishes type is with Osman Sameja and his Ozmillion Yorkshire Terriers.   He never goes to outside studs, his dogs carry 5,6,7 upwards generations of dogs he has bred himself and he keeps a closed breeding programme.  Likewise some of the most successful cat breeders line breed onto their most successful lines.

I bet he had to do a lot of culling of failures to reach that position, though.

No-one knows that except him so we cannot hypothesis!   He may not.   In-breeding doesn't always produce mutants.    Likewise complete outcrosses don't always provide hybrid vigour.

In-breeding produces no higher a ratio of mutants than any other breeding. Mutation is random. What inbreeding does is brings to the fore characteristics that were previously hidden - it shows up all the recessives. It can't create something that wasn't already there.

And that is where it is so useful.  When bringing in new bloodlines to breed close you hopefully will discover what negatives you ahve brought in rather than perhaps not discover tehm for genratiosn when it may be almost impossible to breed away from that individual.  Inbreeding is a useful tool for those who know how to wield it.

A very useful tool indeed, but only in the hands of someone prepared to face the consequences of exposing the negatives as well as accentuating the positives.

I wonder how the packs survived, when they were left to nature, the strongest male would mate all the bitches on heat, mother, sister.
Then the bitches with false pregnancy's  would help feed all the young. A lot is common sence that is all that is needed. If you also breed outbreed dogs you can still have problems. If you breed half sisters or brothers, you just advise that they should be breed with another line to reduced the chance of having problems in the next generations young. No mating with any bitch or dog is guaranteed 

Actually, that doesn't appear to be the case. Research suggests that the lower-ranking females weren't mated and didn't reproduce, and they, along with lower-ranking males, are known to leave and join other packs. Mortality, of course, is much higher in feral and wild groups, with the weakest not surviving, whereas tender-hearted breeders often attempt to rear those whelps which are nature's mistakes.

Yes but long established packs are still pretty incestuous affairs be it wolves, lions etc.

Again, infant mortality is high. A breeder deliberately using the same system would have to be prepared to allow the mistakes to perish - as in all breeding, in fact, whatever the degree of genetic closeness.

Infant mortality is probably more down to the climate conditions youngsters are born into, other pack/opposing pack members killing the young and also the availability of food sources.   

With some of the newer breeds of pedigree cats, inbreeding has taken place  deliberately to bring out the recessive genes/traits  eg. Scottish folds, Selkirk Rex for a couple of generations with no dire consequences. 

A couple of generations is nothing. All madmade pedigree breeds are produced initially by very restricted breeding and closure of the gene pool. In the first few generations this will 'fix' the type, giving the breeds their individual characteristics. After that, close inbreeding should be pursued with caution because you can't bring in any 'fresh' genes.

>I wonder how the packs survived, when they were left to nature, the strongest male would mate all the bitches on heat, mother, sister.

Er no that rarely if ever happens

The lower ranked females appear to have their seasons/fertility supressed due to the levels of glucocorticoids

>The alpha female will suppress the breeding activity of other females both in and out of mating season by displaying her dominance (Derix and Can Hooff, 1995). When the alpha male prevents extra-pair copulations, he will use direct aggression. The subordinate males' sexual behavior is influenced largely by the alpha male. If a subordinate male wishes to direct his attention to a particular female, and the alpha male also prefers that female, the alpha would prohibit courship attempts by the subordinate male. The subordinate will then redirect his attention to the other females in the pack.

The levels of glucocorticoids rise due to stress & this affects the reproductive system

As to inbreeding this is unlikely to occur If you read the information on the link(the avoid of inbreeding is a way down the page)in the normal course of events, this will occur in captive packs of course & one reason that they are not suitable for studying true wolf behaviour

Basically by the time the young are mature enough to become Alpha they will have dispersed.

In herd anumals liek Deer a Buck is unlikley to remain supreme long enough to mate his daughters, and if he is so strong and virile that he does it woudl only be for the oen generation, adn if the offspring are not strong they will not reproduce themselves.

That is my opinion also. You can bring in new lines carefully by using dogs of similar type. That is of course if you want to keep that type and you are not trying to change something..

Hidden recessive genes can sit there for generations then when you have your 1st litter which is a hereditary disaster , in the recessive gene problem you can immediatly tell the parents are carriers but it is very difficult to find who brought it in the line in the 1st place, what others are carriers etc  if they are all much of the same dogs all through the pedigree.  This often happens and poor dogs have the finger pointed at them for nothing.   If you have this senario and you don't know where it decends from you have to then play russian roulette in the next few litters..

I have been reading on and off Control of Canine Genetic Diseases by Padgett recently and I chop and change my mind daily whether for example a breed collectively should eliminate a carrier immediately from the gene pool or not.  I can think of 10 reasons either way depending on what day you ask me.

Keeping a carrier and someone responsible doing trials with it to help the breed may be of benefit. I personally wouldn't ever do it nor would I do what I consider inbreeding matings but standing back and looking at the whole picture is interesting at times and I can understand the need for things at times.

As Brainless has said it is for the very verr clever and responsible people who would be prepared to cull litters if need be and those that would be 100% totally honest.

Look at the health issues in the cats :-) that would scare you to death..

There's only health issues if you let them get hold.   I haven't had a problem with 2 pedigree cats.      And I have several people who are more than willing to entertain Zelli if I were to go for an outside stud (Which is likely) from here to Germany!

I wasnt meaning you personally :-D   just in general. Off the top of my head one of the exotic breeds had to bring in a rule about the nose not being above the eye level as it had gotten so bad. I think we have discussed this in the past have we not.. ( or am I having a brain wave) :-)

I know your standard with the cats is just like you are with your dogs :-) your a bit stuck for both where you want to go to stud :-)

I know...but I'd rather have principles and stick with them! 

I have 7 interests already in puppies from people who've shown, are showing or who want to show, for my next litter and I don't even have a bitch to breed from yet!

Off the top of my head one of the exotic breeds had to bring in a rule about the nose not being above the eye level as it had gotten so bad.

No no no! Totally wrong! The infamous "nose leather rule", relating to Persians and Exotics (well actually when it was brought in, there WERE no Exotics yet of this type in the UK), were brought into being by breeders on the committe of OTHER breeds (!!!) who just did not like the look of them. They had no evidence whatsoever of any health problems relating to the type, and still haven't. Each and every judge, and virtually all breeders, have ever since then  ignored this rule ("The upper edge of the nose leather must not be above the lower edge of the eye") and indeed we have had cats winning the Supreme show with this type. I.e. the GCCF is not doing anything about  it being broken, not even at their one and only own show. It was a pointless rule brought in by the wrong people for the wrong reasons and it's high time it was scrapped ...... I thought myself, back then, it was a GOOD rule, I fully believed all the hype about how unhealthy the typy (then referred to as ultra) cats were. Then I came to a point where I no longer had anything worthy of showing, as only the typier cats were winning, and I ended up getting some typy cats of my own. I was surprised to find they were generally healthier than the less typy ones, with for instance LESS runny eyes and less undershot bites, than the older ones with the longer faces.

Forgot to say that 2 of the top producing dogs in our breed in the last 7 years are from outcross matings.

I do agree though that line breeding is very successful it is the "inbreeding" for me that is too risky..    and where you have given the example of a successful kennel, there are quite a number and most people could think of some probably that have been ruined from constantly inbreeding/line breeding..because of health, lose of quality in particular areas etc.

I can personally think of a few off the top of my head from various breeds that people would generalise as "lost it"..

When I personally refer to type, colour is never a factor.   Type to me is construction even in breeds where various colours are acceptable.  If you put 6 puppies in front of me and ask me to put them into type colour would  never be the group decider.

Thing is Pam you have a breed where type is fairly consistent throughout regardless of pet or show quality.  With the LM being a mainly hunting breed in the world besides the UK, Australia & NZ, dogs are bred for performance rather than looks hence type & conformation is fairly inconsistent throughout even amongst siblings.   Even here you can view a class of dogs and see variations in type. 

When I stated colours it was for ease of terms and more unstandable for the board.  If I had said Kelsey looked like Lucky and Miranda looked like Ollie, it would mean nothing but I did tend to find that the former pairing (blue roans) looked nothing like the latter pairing (Very white & black) and it was like that amongst the rest of the litter.  But in my second litter I went back into the lines behind the dam and type was so much more consistent as was size, heads, bone, coat type etc.

Twice in, once out is a very well known old husbandry term - it means you breed twice into the lines and then go out once, but even then you don't out for a total outcross.

Anyone can mate 2 dogs together and hope for something good.   However I have seen the dogs in the 4th & 5th generations of my dogs pedigrees in fact dogs that are now off their pedigrees so I'm aware of those individual dogs positives & faults which determines what lines I chose to pick back up on & those I will avoid.

Thing is Pam you have a breed where type is fairly consistent throughout regardless of pet or show quality.

Oh Christine I nearly fell off my chair there :-D :-D  that couldnt be any further from the truth..  it is incredibly varied probably worst than most breeds you see type vary incredibly size and weight of over 100% in weight  can you imagine that variance in a LM :-D    If you saw 2 girls I have just now and you could enlarge them into a big breed you would get the fright of your life. One just making the height standard , back length of about 7 inches older type in head, tiny neat ears etc..   the other bitch is about 2 inches bigger, far rangier , leggier and has a more southern type of head , larger with a deap stop, shorter nose and bigger ears..   I won't even start with the movement differences :-)   and these are 2 bitches of show quality I own and show. 2 completely different types.

It is funny how we see other breeds eh? I Do it myself also :-)

But in my second litter I went back into the lines behind the dam and type was so much more consistent as was size, heads, bone, coat type etc.

Exactly you acheived this from line breeding and probably to a degree type breeding as you liked the dam behind. What you did wasn't in breeding. I don't think anyway :-)

That is the point I was trying to originally make I think you can acheive good results from Line breeding and type without inbreeding.  Inbreeding for me is too worry some for health in a day where people would frown about cullng of whole litters.

Twice in, once out is a very well known old husbandry term - it means you breed twice into the lines and then go out once, but even then you don't out for a total outcross.  Yip know exactly what you mean and that is I guess what most do..

But do you have 'Kerry Blue' looking Westies or 'Staffordshire Bull' looking Westies because we have Munsters that have a 'spaniel type' appearance, likewise some that look setterish, some like Retrievers and some even like Border Collie X's.......

Regardless of measurements of backs & height standards, and variances in heads & stops, in the main you are looking at a WHWT some Munsters you'd be hard pushed to know what they were, even if at all pedigree.

I hold my hands up and say I've never read a book about genetics or anything like that, I think the proof of the pudding is in what you produce and whether you have consistent winners in each litter, a litter that is typy and can reproduce good type. 

If I were breeding 3-4 litters a year and pet homing most because they weren't up to scratch I would be wondering where I was going wrong.   Likewise those in my breed who have bred several litters and haven't had a KCSBNo winner yet.

I hold my hands up and say I've never read a book about genetics or anything like that, I think the proof of the pudding is in what you produce and whether you have consistent winners in each litter, a litter that is typy and can reproduce good type. 
  Totally agree with you :-)

If I were breeding 3-4 litters a year and pet homing most because they weren't up to scratch I would be wondering where I was going wrong.   Likewise those in my breed who have bred several litters and haven't had a KCSBNo winner yet.   

It depends of the competition in each breed also Christine and depends on the measure of " scratch"  That is whole different angle and would probably make it's own thread :-) .  If you have a breed where there are classes of 10 plus the competition is so far greater so the quality has to be spot on.     

Off the top of my head my last what I would class as decent wins/placings would be 2nd in a PG class of 17 and 3rd in Limit class of 15 at 2 consecutive shows.  Both of these placing to me would make me comfortable in what I have shown that day and bred. That was with a bitch that had only been shown once before over a year ago.

Now some people with low entries in their breed these placings would be worthless wins.

I do know what you mean though and totally agree with you..  :-)