Jump to content
Dogomania

wondering................


science_doc

Recommended Posts

  • Replies 121
  • Created
  • Last Reply

Top Posters In This Topic

K, I realize that and am not "dissing" anyone. Simply pointing out the fact that [b]I FEEL [/b]Poofy has a good understanding of canine genetics. That is my opinion and I feel that anyone reading this thread could learn a lot from Poof. I have knowledge and great interest in this area and but am not going to post my .02 because I don't want my everyword taken out of context BUT am ENJOYING reading the info posted. :lol: :lol:

Link to comment
Share on other sites

this is one of them. not a dog i could buy but i just want to get a feel of what is to close. it seems to me in the APBT world In/Line breeding is a common thing. which alot of breeders aren't to clear in explaining why they did it that way. It's almost like they are trying to keep the recipe secret.
[url]http://www.apbt.online-pedigrees.com/public/printPedigree.php?dog_id=51115[/url]

Link to comment
Share on other sites

Hobbit said:

"I'm not saying that you are wrong, .... only misinformed."



Well Hobbit I never said it did not decrease it, only not as much and If I am wrong so are Klug and Cummings. And I quote

" Inbreeding depression is a measure of the loss of fitness caused by inbreeding. In domesticated plants and animals, inbreeding and selection have been used for thousands of years, and these organisms already have a high degree of homozygosity at many loci. FURTHER inbreeding will usually produce only a SMALL loss of fitness. However in breeding among individuals fro large, RANDOMLY mating populations, can produce HIGH levels of inbreeding depression."


So no I am not misinformed.



As for hybrids and cross breeds. Quoted from Klug and Cumming

" If members of two favorable lines are mated, hybrid offspring are often more vigerous in desirable traits than is either of the parental lines. This phenomenon is called hybrid vigor."

When you use the word hybrid, in dealing with a breeding program, it can be interchanged. The word Cross breed, means just that, two distinct and different breeds...which can also be reffered to as a hybrid in some sense of the word.

Out crossing and Hybrid are related in refference to a breeding program of what ever type (plant or animal).
Yes, Hybrids can be a cross of different species. However that is limited. Very few hybrids between species are successful because of the un-equal number of chromsomes between parents, which is why, in most cases the offspring are sterile.

Link to comment
Share on other sites

[quote name='bullygirl29532']this is one of them. not a dog i could buy but i just want to get a feel of what is to close. it seems to me in the APBT world In/Line breeding is a common thing. which alot of breeders aren't to clear in explaining why they did it that way. It's almost like they are trying to keep the recipe secret.
[url]http://www.apbt.online-pedigrees.com/public/printPedigree.php?dog_id=51115[/url][/quote]


It's mostly done because that's just the way it's been done for YEARS. They can't explain why --- because they dont' know why, all they know is that it's been done that way for years. No offense meant to anyone by this statement.

An example: I was hired as a consultant for a Hereford Ranch. The old men were having calving problems, diminished birth weight, low rate of gain, small size at maturity, and an array of other problems.

Looking at their herd sire -- he was the same sire for the last 7 years! Their bloodlines were the same inbreeding for the last 30 years. They never sold any of the heifers, nor did they ever change bloodlines for their sire. When the sire became old, they would keep a bull from the herd.

A mess, to say the least. I asked them WHY they bred like this? Their response was, "because it's always been done like this. Our father and grandfather bred like this".

I suggested they sell the entire herd and start over. I thought they'd bother drop dead from a heart attack right there on the spot in the pasture. They had NO working knowledge of genetics and refused to change their breeding practice.

I was successful, after a year of 100% calf loss, in talking them into at least buying an outside bull from proven lines. Their problems are still there, and will continue and I told them so.

Link to comment
Share on other sites

Thats really wild hobbit...as you would think farmers would want as high of a yield as possible...and the only way to achieve that would be a lower COI...really strange that they did not use that practice as I know many horse breeders and beef cattle people...do. I have seen beef cattle persons use frozen semen out of what ever bull was chosen as the best producer, sticking to COI of less then 2%.

What kind of problems were they seeing? Just high mortality or what? do they know what was causing the still births? Seems like they would have brought in at least a few different bulls to decrease depression?

Link to comment
Share on other sites

[quote name='Poofy']Thats really wild hobbit...as you would think farmers would want as high of a yield as possible...and the only way to achieve that would be a lower COI...really strange that they did not use that practice as I know many horse breeders and beef cattle people...do. I have seen beef cattle persons use frozen semen out of what ever bull was chosen as the best producer, sticking to COI of less then 2%.

What kind of problems were they seeing? Just high mortality or what? do they know what was causing the still births? Seems like they would have brought in at least a few different bulls to decrease depression?[/quote]


[b]Inbreeding has definite effects on all traits[/b], increases in inbreeding delays reproductive times and results in lighter weights at 120 and 360 days. Inbreeding coefficients should be considered when deciding on the mating of sires and dams, [b]in order to limit the possible negative effects of inbreeding on productive and reproductive traits[/b].

They were set in ways, because that typical breeding practice was practiced by their father and by his father. They had no knowledge of genetics or why their production was low.

90% of the calves borned had to be pulled. These were not first time heifers, they were 3rd calf cows. The bull was notorious for putting hugh heads and shoulders on the calves. The cows did not have the pelvic girdle to accomodate the large sized calves. Some of the calves only lived a few hours, unable to stand and nurse. Some cows simply did not produce enough milk, had no mothering ability, teats too large, prone to mastitis. Some cows did not conceive (low fertility). The bull had a low libido and would not cover all the cows in heat (even though the herd was small).

[b]For those who are unfamilar with the meaning of Inbreeding coeffients:[/b]
The standard definition of inbreeding is that it is any scheme which results in the sire and the dam having common ancestors. This common heritage is expressed by a parameter called the inbreeding coefficient, first proposed by Sewell Wright in 1922. Designated F by Wright (but more commonly IC or IBC by breeders), it can theoretically range from 0 to 100%, and indicates the probability that the two alleles for any gene are identical by descent. Though the primary consequence of inbreeding is to increase homozygosity, the IC is not a direct measure of homozygosity because the two alleles may be the same for other reasons. Within a breed, some proportion of all the genes will be the homozygous because there was only one allele to start with. In that sense, the IC may be regarded as indicating what proportion of the remainder have been made homozygous by inbreeding.

The inbreeding coefficient is a function of the number and location of the common ancestors in a pedigree. It is not a function, except indirectly, of the inbreeding of the parents. Thus, one can mate two highly inbred individuals who share little common ancestry and produce a litter with a very low IC. (Because the potential number of ancestors doubles every generation, eventually you reach a point where the number of ancestors exceeds the number of individuals alive at that time. You are, therefore, bound to find some common ancestors if you go back far enough.) Conversely, it is possible to mate two closely related dogs, both of which have low ICs, and boost the IC substantially.

Link to comment
Share on other sites

[quote name='bullygirl29532']this is one of them. not a dog i could buy but i just want to get a feel of what is to close. it seems to me in the APBT world In/Line breeding is a common thing. which alot of breeders aren't to clear in explaining why they did it that way. It's almost like they are trying to keep the recipe secret.
[url]http://www.apbt.online-pedigrees.com/public/printPedigree.php?dog_id=51115[/url][/quote]

Whilst arguing amonst yourselves everyone :o
Has any one taken the time to look at this pedigree on the link given above :roll:

there seems to be quite a bit missing :lol:

Link to comment
Share on other sites

[quote name='bullygirl29532']this is one of them. not a dog i could buy but i just want to get a feel of what is to close. it seems to me in the APBT world In/Line breeding is a common thing. which alot of breeders aren't to clear in explaining why they did it that way. It's almost like they are trying to keep the recipe secret.
[url]http://www.apbt.online-pedigrees.com/public/printPedigree.php?dog_id=51115[/url][/quote]

Chan's Dick and Chan's Athena -- 1/2 brother and sister
Garrett's Floyd (2XW) was bred to his daughter --- Chan's Eve.
Garrett's Bridgett & Garrett's Floyd (2XW) --- 1/2 brother and sister.
Garrett's Floyd was bred to his daughter -- Chan's Crickett II

I would call this inbreeding, tightly inbred. Father to daughter is better (genetically speaking) than brother to sister --- IF inbreeding just has to be done.

Personally, I would not breed this close --- the same results can be achieved without close inbreeding.

Link to comment
Share on other sites

[quote name='bullygirl29532']now her sire would be INbred while the bitch would be LINEbred. which would make the bitch in question inbred due to her sharing Garrett's floyd so close. Did that make sense to anyone else? :)[/quote]


Dam is from 1/2 brother to sister breeding; from father/daughter.
Sire is from father/daughter breeding from a father that is 1/2 brother to sister offspring.

Tightly inbred, both lines.

Link to comment
Share on other sites

Offspring List
Siblings List
Pedigree Statistics


4 GENERATION PEDIGREE
IDOL'S ROCKETT

BREEDER: CHRISTOPHER L. IDOL
OWNER: JEFF SMITH
SEX: FEMALE
COLOR: BLACK/WHITE MARKS
POSTED: 2001-09-28
LAST MODIFIED: 2002-03-16
No OF VIEWS: 2681 times

[url]www.carolinagamedogs.com[/url]



Generations in Pedigree
First Second Third Fourth
(Sire) CHAN'S QUARTER BACK GARRETT'S FLOYD (2XW) CH CRENSHAW'S JEEP (4XW) ROM CH FINLEY'S BO (6XW)(1XL) ROM
CH J.CRENSHAW'S HONEYBUNCH ROM
GARRETT'S BRIDGETT CH CRENSHAW'S JEEP (4XW) ROM
J.CRENSHAW'S DOLLY
CHAN'S EVE GARRETT'S FLOYD (2XW) CH CRENSHAW'S JEEP (4XW) ROM
GARRETT'S BRIDGETT
CHAN'S CRICKET II GARRETTS FLOYD (2XW).
SHADY HILL'S CRICKET
(Dam) IABINET'S MOONSHINE JR. IKE'S BLACK DICK (AKA RAZOR) CHAN'S DICK GARRETT'S FLOYD (2XW)
CHAN'S BLACK GIRL
CHAN'S ATHENA GARRETT'S FLOYD (2XW)
CH CHAN'S CHECKER
[size=7][color=red]

WHERE IS THE DAMS DAM HERE?[/color][/size]

Link to comment
Share on other sites

PEDIGREE STATISTICS
IDOL'S ROCKETT



SIRE: CHAN'S QUARTER BACK
DAM: IABINET'S MOONSHINE JR.
OFFSPRING: 2
FULL BROTHERS/SISTERS: 0
HALF BROTHERS/SISTERS (SAME SIRE): 4
HALF BROTHERS/SISTERS (SAME DAM): 0
BEFORE-NAME TITLED OFFSPRING (CH, GR CH, ETC...): 0
AFTER-NAME TITLED OFFSPRING (ROM, POR, ETC...): 0
4 GENERATION GENETIC CONTRIBUTION:

CHAN'S QUARTER BACK 50%

GARRETT'S FLOYD (2XW) 50%

IABINET'S MOONSHINE JR. 50%

CH CRENSHAW'S JEEP (4XW) ROM 25%

IKE'S BLACK DICK (AKA RAZOR) 25%

CHAN'S EVE 25%

GARRETT'S BRIDGETT 18.75%

CHAN'S ATHENA 12.5%

CHAN'S CRICKET II 12.5%

CHAN'S DICK 12.5%

CHAN'S BLACK GIRL 6.25%

CH CHAN'S CHECKER 6.25%

SHADY HILL'S CRICKET 6.25%

J.CRENSHAW'S DOLLY 6.25%

CH FINLEY'S BO (6XW)(1XL) ROM 6.25%

CH J.CRENSHAW'S HONEYBUNCH ROM 6.25%

GARRETTS FLOYD (2XW). 6.25%

Link to comment
Share on other sites

:-?

I have read this thread very carefully.

I have a few questions, but first I would like to point out an observation.

This thread was started as a question about cross-breeding a particular dog breed to another dog breed's line in order to fix existing problems in the first breed. ie: GSD to other similar shepard.

The opposing argument has pretty much been whether excessive in-breeding or outcrossing is better for the breed. There really has not been any argument for loose line breeding vs. out-crossing vs. cross-breeding.

The arguments, however, have been very informative and educational.

I understand that constantly inbreeding a line will eventually degenerate the line, but I would think that you would lose true structure by constantly outcrossing a line. I also don't see how cross-breeding can really benefit anything other than creating a half-breed, if for only one generation.

Now my question is pertaining to out-crossing. - If inbreeding creates a genetic environment for good and bad diseases, ailments etc. to surface when normally they would not of, then wouldn't outcrossing make it a severly recessive gene? I don't understand how if inbreeding brings a good or bad trait to the surface that outcrossing would get rid of it permanently, it seems to me that it would just become a recessive gene.

Doc wrote:
You are 100% wrong that outbreeding will not get rid of mutations within the population. When you outbreed you can ELIMINATE the bad allelel from the POPULATION by selective breeding, thereby ELIMINATING the disease. [b][color=red]What you are saying is that selective breeding is what is eliminating the disease not the outcrossing on it's own. Could this not also be achieved through selective line-breeding?[/color][/b]

Are you aware how scientist established genetic disease models in rodents(before the age of molecular cloning, now we can engineer our diseases)? We inbreed them for generation after generation until something went wrong. That literally ment EVERYTHING and ANYTHING. [b][color=red]Were the rodents in these experiments tested to find the best representatives before breeding again, or was quality not an issue. Has there been an experiment where only the best representative of each litter was in-bred?[/color][/b]

Thank you all for your genetics lessons.

:angel:

Link to comment
Share on other sites

[quote]but pointing the finger as it were and saying that he/she

Quote RR:-
by far has more understanding in this area than MANY of the breeders here.

Is in fact "dissing" the other posters on this thread and the other breeders who use this forum...
[/quote]

No that is wrong. Doesnt mean other breeders know nothing, just that one person has displayed some exceptional knowledge.

Link to comment
Share on other sites

[quote name='Rosebud']:-?


I understand that constantly inbreeding a line will eventually degenerate the line, but I would think that you would lose true structure by constantly outcrossing a line. [color=red][b]Structure would not be lost if a breeder was selective in chosing which sire or dam to breed with (speaking of breeding within the same breed). If you are speaking of breeding to another breed; you would want to breed to a breed of like structure, for the traits that you are wanting to incorporate into the original breed --- or for the traits which you want to dilute. Then take that offspring and breed back into the original line of original breed. Of course, if you are wanting to dilute a certain trait --- you must not breed back to the dog/bitch whose trait you are trying to get away from.[/b][/color]

I also don't see how cross-breeding can really benefit anything other than creating a half-breed, if for only one generation. [color=darkred][b]Cross-breeding into another breed could be beneficial. You would, as stated above, also want to breed to a genetically sound dog. That "half-breed" pup, would then be bred back to the original breed; that offspring would then be bred back to the original breed, also. If a person is wanting to dilute a genetic defect; they could do so by NOT tightly inbreeding within the same breed. They could breed into another bloodline (one that is genetically sound) and select to keep ONLY genetically sound offspring and eliminate the defective ones. [/b][/color]

Now my question is pertaining to out-crossing. - If inbreeding creates a genetic environment for good and bad diseases, ailments etc. to surface when normally they would not of, then wouldn't outcrossing make it a severly recessive gene? [b][color=red]No. When you inbreed there is a higher chance that the recessive genes will pair --- because the parents both have many of the same genes. Every offspring obtains a copy of half the sire and half the dam. If you are breeding brother to sister; then both may have some of the same recessive genes (genetic defects) that could pair. If you bred to an outside dog (same breed, different bloodlines) --- they have different gene pairs and the likelyhood that a recessive would pair is not very high.[/color][/b]

I don't understand how if inbreeding brings a good or bad trait to the surface that outcrossing would get rid of it permanently, it seems to me that it would just become a recessive gene. [color=darkred][b]Breeding to an outside line would increase the chances that the recessive (defect) gene would be masked, because of the statement above. It is "hidden". Thru selective breeding, the defect would not surface because of dominant genes. A person would (MUST) have to have a working knowledge of genetics in order to achieve this. If a dog is a carrier for a certain disease --- you can, thru selective breeding (breeding to a dog that is not a carrier nor is affected), breed so the gene does not surface. In the long run, it would be better to eliminate the carrier from the gene pool altogether (neuter or spay) and not use that particular dog for breeding. Some genes are hidden that a breeder may not know is in his line. Breeding brother to sister will surely bring those "hidden" genes to the surface. If these are defects, an ethical breeder, would remove these dogs from his program, along with the offspring. This does NOT mean that this has eliminated the problem within the line (there could be other problems). Some genes can not be eliminated and MUST be dealth with accordingly. [/b][/color]


[color=blue]Doc wrote:
You are 100% wrong that outbreeding will not get rid of mutations within the population. When you outbreed you can ELIMINATE the bad allelel from the POPULATION by selective breeding, thereby ELIMINATING the disease. [b]What you are saying is that selective breeding is what is eliminating the disease not the outcrossing on it's own. Could this not also be achieved through selective line-breeding?[/color][/b]

[color=blue]Are you aware how scientist established genetic disease models in rodents(before the age of molecular cloning, now we can engineer our diseases)? We inbreed them for generation after generation until something went wrong. That literally ment EVERYTHING and ANYTHING. [b]Were the rodents in these experiments tested to find the best representatives before breeding again, or was quality not an issue. Has there been an experiment where only the best representative of each litter was in-bred?[/color][/b]

Thank you all for your genetics lessons.
:angel:[/quote]

Link to comment
Share on other sites

You said:Doc wrote:
You are 100% wrong that outbreeding will not get rid of mutations within the population. When you outbreed you can ELIMINATE the bad allelel from the POPULATION by selective breeding, thereby ELIMINATING the disease. What you are saying is that selective breeding is what is eliminating the disease not the outcrossing on it's own. Could this not also be achieved through selective line-breeding? "


Absolutely. Selective breeding is the key.

Link to comment
Share on other sites

:D

Thank you Hobbit & Poofy for your responses. This thread has been very educational and I am glad to learn all of this.

I also thought that the sample line was heavily inbreed and I didn't actually study it, just saw the same names over & over on all three sides.

:angel:

Link to comment
Share on other sites

Guest Anonymous

I do know that too much inbreding can cause problems. As I stated, linebreeding and cross breeding are important as well. If you know about the different families/lines of the APBT you know that each of these lines carry certain traits. You inbreed to keep the traits strong and outcross when needed.Some people inbreed too much, some not enough. Your books will not tell you when you get to either point unless there is physical proof you have gone too far. I know when I need to bring another line in. Not from books but from experience. Not only from my experience but from dogmen who have been breeding most of their lives and are well known. I may not know all the sceintific genetic terms and opinions but I know what these breeders have done, and they have done it better than anyone.
"Substandard" dogs, huh? I know several people who will [b]strongly[/b] disagree with you. And I guarantee anyone knowing about the bloodlines of my breed would love to have any of my dogs. And if you put someone with all this genetic knowledge and compare their dog to mine, mine will still be the dog most choose.
One thing you must remember with breeders of the APBT is that we cull, and cull hard. Culling is also a very important part of breeding.

Link to comment
Share on other sites

[quote name='Hmmmm']I do know that too much inbreding can cause problems. As I stated, linebreeding and cross breeding are important as well. If you know about the different families/lines of the APBT you know that each of these lines carry certain traits. You inbreed to keep the traits strong and outcross when needed. [b][color=darkred]You do not have to tightly inbreed to achieve this. [/color][/b]

Some people inbreed too much, some not enough. Your books will not tell you when you get to either point unless there is physical proof you have gone too far. [b][color=red]Physical proof, at the expense of the dog --- I'm NOT willing to sacrifice my dogs because of an unwillingness to *hear* what has been proven. There is NO need for the sacrifice or severe culling that is done on a frequent basis by these *dogmen --- if a person has the knowledge to achieve what they are breeding for, these *mistakes* would occur less frequently. [/color][/b]

I know when I need to bring another line in. Not from books but from experience. [b][color=red]IF you are leaning towards saying or implying that my knowledge of genetics is all book learning....you are sadly mistaken. I've been breeding livestock, dogs included, for almost 35 years.[/color][/b]

Not only from my experience but from dogmen who have been breeding most of their lives and are well known. I may not know all the sceintific genetic terms and opinions but I know what these breeders have done, and they have done it better than anyone. [b][color=darkred]How do you test for mental instability in dogs? Better? If you call "better" at the expense of the dog, I guess so. [/color][/b]

"Substandard" dogs, huh? I know several people who will [b]strongly[/b] disagree with you. And I guarantee anyone knowing about the bloodlines of my breed would love to have any of my dogs. And if you put someone with all this genetic knowledge and compare their dog to mine, mine will still be the dog most choose. [color=red][b]Your dog would be chosen by a person that had no knowledge of genetics. Someone that would not understand the mental damage that occurs from the continual practice of tightly inbreeding. Chosen by someone that would not understand how "fixing" a gene could/would hurt the breed in general. You are closed minded on this subject and it's fruitless for this conversation to continue. Your mind is made up, has been made up and you have NO idea how deeply you are hurting the dogs that you have --- you may not "see" what I'm talking about, understand what I'm talking about, but at the mental level, molecular level ---- You are playing a dangerous game at the expense of the mental stability of your dogs. [/b][/color]One thing you must remember with breeders of the APBT is that we cull, and cull hard. Culling is also a very important part of breeding. [color=darkred][b]AGAIN, if a person has the working knowledge of genetics and how to manipulate and use this knowledge in their breedings --- severe culling would not be a necessary factor as frequently as it's done in the APBT circle. I guess if a person doesn't mind knocking puppies in the head or killing young adults, then YOUR experienced way of breeding is for them[/b][/color].[/quote]


Reread my post -- slowly --- I never called your dogs substandard.

Tell me what feeling you have or how you know to outcross? What are the indicators?

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...