My wiew on inbreeding

The way I see it inbreeding is a much worse problem on population level than on the individual level. Inbred on population level means we are out of options for the future development of the population. Inbred on individual level means I cull the individual if it is sub-par and keep it if above par (by that I mean ordinary culling criteria, like fertility, hardiness, health and so on).
Why be afraid to use an animal that is all right, because it is inbred?

And let us discuss regression/depression! Les us say that I line breed a bull to his half sisters.
Some of the offspring will be poorer than average, they are to an higher degree homozygous for less preferable genes. I cull them for being poor, thereby lowering the frequency of those genes.
Then there are average and good cattle left. They might then either be heterozygous or homozygous for the preferable genes. We do not know why the good is good, or why the average is average. But by reducing the frequency of less preferable genes in each generation, the homozygousity of preferable genes will increase, by each generation.

In my world there is no such thing as touting that a poor animal is extra homozygous and therefor carries extra heterosis. It might breed better than it looks, but this does not mean it breeds good enough. It does not matter, if all the inherit heterosis is wasted on getting up to par, the bull customer gets nothing.
It needs to be good! It needs to be the same or almost the same in all relevant traits (be it only the maternal traits, or any trait) as the no thought outcrosses around us! Then, and only then are we truly harnessing heterosis. Because then the f1 offspring of the sire will be both good and consistant. Only consistant is not good enough.

So do you think nature is fine with your definition of good genes and will let you select for them and only them with no reaction to restore her preferred balance?


I understood from you post that you are in favour of attempting to decrease variance on an individual basis but not on a population basis... Isn’t that just a matter of degrees? The culled individual in my mind was a sorted population of genes, as is your herd... from the bovine specie gene pool.


When you say “it needs to be the same or almost the same in all relevant traits (be it only the maternal traits, or any trait) as the no thought outcross around us!”

That is a confusing statement to me... For one, if you decrease the frequency your perceived visible bad traits are you increasing the frequency of the visibly perceived good? If so would not the population be better than the no thought outcross in the relevant traits, if not better why bother limiting the population to a herd or breed?

Hilly wrote:

So do you think nature is fine with your definition of good genes and will let you select for them and only them with no reaction to restore her preferred balance?


When you say “it needs to be the same or almost the same in all relevant traits (be it only the maternal traits, or any trait) as the no thought outcross around us!”

That is a confusing statement to me... For one, if you decrease the frequency your perceived visible bad traits are you increasing the frequency of the visibly perceived good? If so would not the population be better than the no thought outcross in the relevant traits, if not better why bother limiting the population to a herd or breed?

If nature is strongly contesting the choices of the breeder, the breeder is likely not breeding for his environment. He is wise to breed for his environment, this saves sorrow for himself and the bull buyers.

The "no thought outcross around us" (within the "pure breeds") has a certain heterosis level that is to their advantage in the comparison against the linebred cattle. That is before they see the crossbred progeny. This small amount of within-breed-heterosis (as a result of fire-to-ice matings) must be overcome by the linebreeder with more quality.

I’m not trying to be a pain in the ass, but what animals qualify to be considered part of a pure breed and who is in charge of inspecting for outside contamination into that pool? This is why I like the idea of independent strains instead for breeds as the breeder has control over the purity of his pool, the usefulness of which will be determined as they are systematically used interdependently with other strains.

Quote :

And let us discuss regression/depression! Les us say that I line breed a bull to his half sisters.
Some of the offspring will be poorer than average, they are to an higher degree homozygous for less preferable genes. I cull them for being poor, thereby lowering the frequency of those genes.
Then there are average and good cattle left. They might then either be heterozygous or homozygous for the preferable genes. We do not know why the good is good, or why the average is average. But by reducing the frequency of less preferable genes in each generation, the homozygousity of preferable genes will increase, by each generation.

In my world there is no such thing as touting that a poor animal is extra homozygous and therefor carries extra heterosis. It might breed better than it looks, but this does not mean it breeds good enough. It does not matter, if all the inherit heterosis is wasted on getting up to par, the bull customer gets nothing.
It needs to be good! It needs to be the same or almost the same in all relevant traits (be it only the maternal traits, or any trait) as the no thought outcrosses around us! Then, and only then are we truly harnessing heterosis. Because then the f1 offspring of the sire will be both good and consistant. Only consistant is not good enough.

How many years of linebreeding of your own herd has given you this opinion?

EddieM wrote:

How many years of linebreeding of your own herd has given you this opinion?

I am not line breeding. However I am interested in the subject, and keep ears and eyes open. I am 34 years and have been involved in breeding decisions for some 20 years. I admit I am a beginner compared to some others. Tell me your truth?

I cannot claim "truth" in linebreeding, just opinion. If environment sifts out the poorest of choices in parent stock, then it is odd that 13 lines of Herefords were dropped that left only the Line 1 Herefords. Were the other 13 lines from the wrong environment or were the genes not there to make a tighter bred group/family/line of cattle? To select the starter group is always a roll of the dice. Did you really pick the ones that will have clean genes, be able to sustain for your selections, be there for the long run? Will you, generation after generation, make the right choices of the breeders?

We have chickens that are a line for decades. Some outcrossing has been done to save them. If you could see the wierdness that comes from them you'd have to wonder about linebreeding them another generation. I have 3 maternal lines of sheep and am lambing 3 paternal lines of sheep now by breeding sire/daughter or sire/closest relative. I also have a group of ewe lambs that are all half sisters bred to a half sib. They are built on a ewe, #3, that is my maternal choice yet some of the males are quite useful in carcass traits. I also kept two more half brother rams to this group that I will never show to others as anything else other than an experiment. They are #3Xson of #3 (#53) and dam of 3X#53. They are downright ugly and will be tested as outcross sires before they are possibly used as breeders on their half sisters.

The registered fraction of the cows are bred to a sireXdaughter bred bull. He'll breed some first cousins next spring. There are some other linebred animals but nothing unusual. The problem with the cows for me is the time it takes to turn generations.

The "truth" of linebreeding is that on the average you need to be willing to create more lines that will fail than the few lines that will make it for the long term. And if you want to see the ultimate results in your lifetime, you'd better stick to mice and guinea pigs. That was "truth" #2. And "truth" #3 is that you need to work on marketing as strongly as you work on linebreeding your animals unless you want to support your animals.

Perception is reality.

I would handle the yearly culling of the line far better than to guess which animals that should be in the start group!

Meat animals can be linebred as the most (with chickens there is not much limit to the degeneration, but you get my point) culls are worth something as food, even if less than the culls from a non linebred flock/herd. With dogs, many of the culls are worth nothing and needs to be shot, not good business.

About the two ugly rams; to test animals with inbreeding, and use them in crossbreeding if they are good, is in line with my thinking. What will the outcross tell you about them?


These are questions for eddiem, but thoughts from others are wellcome.
Summing up the three first rules:
1. not all lines work
2. cows have long generations an few offspring
3. Marketing is needed for the linebred cattle

There is room for more truths here. Anyone?

"What is Truth?" Pontius Pilate.

tulip wrote:

The way I see it inbreeding is a much worse problem on population level than on the individual level. Inbred on population level means we are out of options for the future development of the population. Inbred on individual level means I cull the individual if it is sub-par and keep it if above par (by that I mean ordinary culling criteria, like fertility, hardiness, health and so on).
Why be afraid to use an animal that is all right, because it is inbred?

Don't assume inbreeding means no variation, hopefully just less variation. There will always be adequate variety to avoid painting your population into a corner.

The other distinction you are not considering in your assessment is the different roles of parent stock and production stock.
Your assessment of parent stock quality and usefullness from a production stock quality definition perspective limits your ability to discuss this topic in its entirety and is leading you to erroneous conclusions. The final assessment of parent stock quality is how they perform as parents not how they performed as progeny themselves. Your "poorer" than average performers as progeny, inbred or crossbred, may in fact be average or better than average performing as parents. If you don't keep and breed the poorer than average heifers from a growth standpoint perspective you won't ever know if they are average or better then average in their parent stock roles.

Dylan Biggs

Dylan Biggs wrote:

tulip wrote:

The way I see it inbreeding is a much worse problem on population level than on the individual level. Inbred on population level means we are out of options for the future development of the population. Inbred on individual level means I cull the individual if it is sub-par and keep it if above par (by that I mean ordinary culling criteria, like fertility, hardiness, health and so on).
Why be afraid to use an animal that is all right, because it is inbred?

Don't assume inbreeding means no variation, hopefully just less variation. There will always be adequate variety to avoid painting your population into a corner.

The other distinction you are not considering in your assessment is the different roles of parent stock and production stock.
Your assessment of parent stock quality and usefullness from a production stock quality definition perspective limits your ability to discuss this topic in its entirety and is leading you to erroneous conclusions. The final assessment of parent stock quality is how they perform as parents not how they performed as progeny themselves. Your "poorer" than average performers as progeny, inbred or crossbred, may in fact be average or better than average performing as parents. If you don't keep and breed the poorer than average heifers from a growth standpoint perspective you won't ever know if they are average or better then average in their parent stock roles.

Dylan Biggs

truth; so well articulated...but traditional selection practices still cloud our mind and overwhelm truth...

MKeeney wrote:

Dylan Biggs wrote:

tulip wrote:

The way I see it inbreeding is a much worse problem on population level than on the individual level. Inbred on population level means we are out of options for the future development of the population. Inbred on individual level means I cull the individual if it is sub-par and keep it if above par (by that I mean ordinary culling criteria, like fertility, hardiness, health and so on).
Why be afraid to use an animal that is all right, because it is inbred?

Don't assume inbreeding means no variation, hopefully just less variation. There will always be adequate variety to avoid painting your population into a corner.

The other distinction you are not considering in your assessment is the different roles of parent stock and production stock.
Your assessment of parent stock quality and usefullness from a production stock quality definition perspective limits your ability to discuss this topic in its entirety and is leading you to erroneous conclusions. The final assessment of parent stock quality is how they perform as parents not how they performed as progeny themselves. Your "poorer" than average performers as progeny, inbred or crossbred, may in fact be average or better than average performing as parents. If you don't keep and breed the poorer than average heifers from a growth standpoint perspective you won't ever know if they are average or better then average in their parent stock roles.

Dylan Biggs

truth; so well articulated...but traditional selection practices still cloud our mind and overwhelm truth...

Cloud, thick and heavy, slowly my mind emerges.

MKeeney wrote:

Dylan Biggs wrote:

tulip wrote:

The way I see it inbreeding is a much worse problem on population level than on the individual level. Inbred on population level means we are out of options for the future development of the population. Inbred on individual level means I cull the individual if it is sub-par and keep it if above par (by that I mean ordinary culling criteria, like fertility, hardiness, health and so on).
Why be afraid to use an animal that is all right, because it is inbred?

Don't assume inbreeding means no variation, hopefully just less variation. There will always be adequate variety to avoid painting your population into a corner.

The other distinction you are not considering in your assessment is the different roles of parent stock and production stock.
Your assessment of parent stock quality and usefullness from a production stock quality definition perspective limits your ability to discuss this topic in its entirety and is leading you to erroneous conclusions. The final assessment of parent stock quality is how they perform as parents not how they performed as progeny themselves. Your "poorer" than average performers as progeny, inbred or crossbred, may in fact be average or better than average performing as parents. If you don't keep and breed the poorer than average heifers from a growth standpoint perspective you won't ever know if they are average or better then average in their parent stock roles.

Dylan Biggs

truth; so well articulated...but traditional selection practices still cloud our mind and overwhelm truth...

Although redundant I feel compelled to put up a post echoing Mike, very well articulated, so much so that it triggers an envious first reaction from me... definitely a gift

Tulip wrote:

If nature is strongly contesting the choices of the breeder, the breeder is likely not breeding for his environment. He is wise to breed for his environment, this saves sorrow for himself and the bull buyers.

Goes to the heart of why we have different breeds. Studied Dr. Bonsma?

I'm glad I agree with Dylan on most everything!

Dylan, Thanks. Mike says truth clouded by traditional practices. I assume he means that traditionally breeders cull based on performance, e.g., weaning weight. In parent stock not the case. What should we look for when culling in the case of parent stock? Jim

Hilly wrote:

MKeeney wrote:

Dylan Biggs wrote:

tulip wrote:

The way I see it inbreeding is a much worse problem on population level than on the individual level. Inbred on population level means we are out of options for the future development of the population. Inbred on individual level means I cull the individual if it is sub-par and keep it if above par (by that I mean ordinary culling criteria, like fertility, hardiness, health and so on).
Why be afraid to use an animal that is all right, because it is inbred?

Don't assume inbreeding means no variation, hopefully just less variation. There will always be adequate variety to avoid painting your population into a corner.

The other distinction you are not considering in your assessment is the different roles of parent stock and production stock.
Your assessment of parent stock quality and usefullness from a production stock quality definition perspective limits your ability to discuss this topic in its entirety and is leading you to erroneous conclusions. The final assessment of parent stock quality is how they perform as parents not how they performed as progeny themselves. Your "poorer" than average performers as progeny, inbred or crossbred, may in fact be average or better than average performing as parents. If you don't keep and breed the poorer than average heifers from a growth standpoint perspective you won't ever know if they are average or better then average in their parent stock roles.

Dylan Biggs

truth; so well articulated...but traditional selection practices still cloud our mind and overwhelm truth...

Although redundant I feel compelled to put up a post echoing Mike, very well articulated, so much so that it triggers an envious first reaction from me... definitely a gift

What I am trying to say is that an individual that is registered is not holy; the fact that it is seedstock does not alter the obvious. It must be culled on the very same principles that that apply for commercial cattle, although not necessarily only for weaning or yearling weight, but real world characteristics none the less. Linebreeding do tend to lead to regression; for growth, vitality, fertility. And quality seedstock is supposed to posess higher quality for these traits. Would it not be the hallmark of an inbred cow to perform like any good cow, so that her quality masks the fact that she suffers from regression?
Are there important capabilities that seedstock need to have, that production stock can do without?

RobertMac wrote:

Tulip wrote:

If nature is strongly contesting the choices of the breeder, the breeder is likely not breeding for his environment. He is wise to breed for his environment, this saves sorrow for himself and the bull buyers.

Goes to the heart of why we have different breeds. Studied Dr. Bonsma?

The late Dr had his moments.

What I am trying to say is that an individual that is registered is not holy; the fact that it is seedstock does not alter the obvious. It must be culled on the very same principles that that apply for commercial cattle, although not necessarily only for weaning or yearling weight, but real world characteristics none the less. Linebreeding do tend to lead to regression; for growth, vitality, fertility. And quality seedstock is supposed to posess higher quality for these traits. Would it not be the hallmark of an inbred cow to perform like any good cow, so that her quality masks the fact that she suffers from regression?
Are there important capabilities that seedstock need to have, that production stock can do without?[/quote]

Registered does not mean seedstock. Seedstock do not need to be culled on the same principles that apply to commercial cattle. Commercial cattle are the production. The producers. The end. Seedstock are bred to be the parents. The source of vigor in a package designed to pass on their traits with regularity and if crossed provide that shot of vigor one time. Seedstock are percieved to NEED higher levels of those traits, because when from the mainstream system they breed down. Regression of the heterozygote. Superior individuals who do not have the ability to pass it on with any regularity.

Keystone wrote:

What I am trying to say is that an individual that is registered is not holy; the fact that it is seedstock does not alter the obvious. It must be culled on the very same principles that that apply for commercial cattle, although not necessarily only for weaning or yearling weight, but real world characteristics none the less. Linebreeding do tend to lead to regression; for growth, vitality, fertility. And quality seedstock is supposed to posess higher quality for these traits. Would it not be the hallmark of an inbred cow to perform like any good cow, so that her quality masks the fact that she suffers from regression?
Are there important capabilities that seedstock need to have, that production stock can do without?

Registered does not mean seedstock. Seedstock do not need to be culled on the same principles that apply to commercial cattle. Commercial cattle are the production. The producers. The end. Seedstock are bred to be the parents. The source of vigor in a package designed to pass on their traits with regularity and if crossed provide that shot of vigor one time. Seedstock are percieved to NEED higher levels of those traits, because when from the mainstream system they breed down. Regression of the heterozygote. Superior individuals who do not have the ability to pass it on with any regularity. [/quote]

Chopping this afternoon as I have the last few days, actually gives me time to think before I post And I thought today how all this inbreeding discussion seems repetitous; already well covered in the Reflections from LL thread...it may be repetitious, but each time we "do it again", we find new gems...and each time , as proven by Kent above, and by Dylan earlier , we learn how to articulate the concepts more clearly...that alone makes these discussions with newcomers so worthwhile to us all...for once, I more thoughts than time to type, so more later...

jhudson wrote:

Dylan, Thanks. Mike says truth clouded by traditional practices. I assume he means that traditionally breeders cull based on performance, e.g., weaning weight. In parent stock not the case. What should we look for when culling in the case of parent stock? Jim

Jim, not ignoring you, but certainly delaying you ...I hope to put up several cull/select scenarios of all degrees of outcrossing and close breeding for critique and discussion in a day or two...the organization of such will be my escape from the hummm of the tractor today...which is a much more pleasant monotony than the crack of shafts and shear bolts breaking in the bagger...
but, we`re getting there...I gotta get a pic of my two row chopper for Larkota soon; he can`t remember such an obsolete machine ever existed

MKeeney wrote:

jhudson wrote:

Dylan, Thanks. Mike says truth clouded by traditional practices. I assume he means that traditionally breeders cull based on performance, e.g., weaning weight. In parent stock not the case. What should we look for when culling in the case of parent stock? Jim

Jim, not ignoring you, but certainly delaying you ...I hope to put up several cull/select scenarios of all degrees of outcrossing and close breeding for critique and discussion in a day or two...the organization of such will be my escape from the hummm of the tractor today...which is a much more pleasant monotony than the crack of shafts and shear bolts breaking in the bagger...
but, we`re getting there...I gotta get a pic of my two row chopper for Larkota soon; he can`t remember such an obsolete machine ever existed

oh Mike I well remember chopping corn with a 2 row Fox cutter with no cab 830 Case for weeks that turned into a month long. why I never got into sports. we use to pull the trucks backwards behind the cutter, push up with an old crawler. it would take a crew of at least 2 men and 3 kids for drivers, not enough kids around today to operate like that. use to think the only reason my folks had me was to put up hay, haul silage, clean bunks, and in my spare time pull weeds in the shelterbelts.
Now I can put all I need in about 15 hours and a checkbook.

Quote :

I would handle the yearly culling of the line far better than to guess which animals that should be in the start group!

Use the life hands you lemons, make lemonade approach to start. Yearly culling has been one of the big questions that we have all asked here at KC.

Quote :

Meat animals can be linebred as the most (with chickens there is not much limit to the degeneration, but you get my point) culls are worth something as food, even if less than the culls from a non linebred flock/herd. With dogs, many of the culls are worth nothing and needs to be shot, not good business.

But if they are inferior then there is still an economic loss.

Quote :

About the two ugly rams; to test animals with inbreeding, and use them in crossbreeding if they are good, is in line with my thinking. What will the outcross tell you about them?

The outcross will let me know if they are truly duds or just exhibiting a high level of inbreeding depression. If they are duds I do not want them as anything.


I lost the rest of your message. When I was talking paternal/maternal I was more speaking of baseing lines on particular rams or particular ewes. I probably misused the terms. One other potential line got culled in the first effort due to a lack of resistance to internal parasites.