Why Linebreed?

[HerefordSire]

novatech...please converse on this thread....

 

[HerefordSire]

Linebreeding will often times result in smaller progeny. The reason is that there is no heterosis. Even though the result may be a smaller individual, using these line breds with an outcross can result in spectacular results. Which may only last 1 geneation. At least this is my understanding. Better talk to people that know more about genetics than me.

I was reading something the other day....could the term heterosis be misinterpreted such that a cross produce no additional output but linebreeding (or inbreeding within a breed) reduces output?

 

[Brandonm22]

Linebreeding will often times result in smaller progeny. The reason is that there is no heterosis. Even though the result may be a smaller individual, using these line breds with an outcross can result in spectacular results. Which may only last 1 geneation. At least this is my understanding. Better talk to people that know more about genetics than me.

I was reading something the other day....could the term heterosis be misinterpreted such that a cross produce no additional output but linebreeding (or inbreeding within a breed) reduces output?

The term you are looking for is "inbreeding depression". It is the main reason why performance breeders are always looking for outcrosses. I am not well versed on the subject but as I understand it it is the exact opposite of heterosis. In heterosis you get a slightly better performance than one would expect from the average of the two parents. With the inbreeding depression effect a closely mated individual performs worse than you would expect from the average of the two parents. I think most experienced linebreeders claim this fades away after the first 3 generations in a linebreeding regimen.

 

[HerefordSire]

Linebreeding will often times result in smaller progeny. The reason is that there is no heterosis. Even though the result may be a smaller individual, using these line breds with an outcross can result in spectacular results. Which may only last 1 geneation. At least this is my understanding. Better talk to people that know more about genetics than me.

I was reading something the other day....could the term heterosis be misinterpreted such that a cross produce no additional output but linebreeding (or inbreeding within a breed) reduces output?

The term you are looking for is "inbreeding depression". It is the main reason why performance breeders are always looking for outcrosses. I am not well versed on the subject but as I understand it it is the exact opposite of heterosis. In heterosis you get a slightly better performance than one would expect from the average of the two parents. With the inbreeding depression effect a closely mated individual performs worse than you would expect from the average of the two parents. I think most experienced linebreeders claim this fades away after the first 3 generations in a linebreeding regimen.

I didn't used the term for a purpose, but thanks for offering Brandon. I have been taught and read that heterosis provides a kick upon a cross. Now I am thinking for the first time, that it is possible a cross doesn't provide a kick but it appears to because the "in breed" inbreeding depression is so great it appears to. Follow me?

 

[JHH]

If you dont linebreed you are just a multiplier. Someone always says that on here.

In my experience (which is not much) I got big B.W. calves and they didnt grow. So I cant tell you about the 3rd generation as they are all gone now. I think linebreeding works well and I havent given up just need to have better foundation to start with. JHH

 

[HerefordSire]

If you dont linebreed you are just a multiplier. Someone always says that on here.

In my experience (which is not much) I got big B.W. calves and they didnt grow. So I cant tell you about the 3rd generation as they are all gone now. I think linebreeding works well and I havent given up just need to have better foundation to start with. JHH

Your experience backs up my new dreamt up theory. I do not think it is a correct theory, but it did enter my mind for some strange reason.

 

[Santas and Duhram Reds]

To answer the question of why linebreed, maybe one should linebreed to ensure one's customer satisfaction. When one's animal is exposed to the customer's herd that is the outcross, they will benefit from your efforts. I am starting to linebreed but have not put enough time into it to really offer much "experience" on this topic. My personal purpose for linebreeding is to give my herd more exposure to a couple of my lines I am most pleased with. Just trying to make a more uniform product.

 

[ANAZAZI]

Really, the heterosis is the kick upwards relative the expectation of what the combination of dam and sire would perform based on their performance.

Now, the natural selection and the breeding that people do to cattle; they both have a tendency to "punish" dominant "bad genes" much harder than recessive "bad genes" because of the recessive genes ability to hide behind "good" genes. Because of this tendency, most alleles that limits health, growth and performance happens to be recessive, as the dominant alleles that cause the same kind of problem are already extinct.
This tendency also makes it more likely that within a restricted population such as a breed, there are recessive alleles of the "bad kind" that sometimes can "come out and play", because they in a particular animal are homozygous. now figure that there are ten or a hundred such alleles within a breed, this pulls down the breed average by roughly a few percent.
And in the other breed the same thing happens, however with other "bad genes" that happens to be present, but with quite the same results.
If these two breed are crossed; it is likely that many of these "bad genes" are masked by "good genes" from the other breed.
There is only a slight heterosis effect when crossing two lines within a breed because they are likely to share most of their "crap".
When you mix hereford and aberdeen angus for example, their gene pools has been apart for a few hundred years, they are less related and tend to share less of the "crap".
Now, if you breed your herf to brahma bull there will be more heterosis, because the more difference in the gene pool the lees "bad genes" they will share.
A composite breed will have a much larger gene pool than a traditional breed, and therefore much lesser risk that one of the recessive genes "finds" a copy of "itself" and is expressed in the phenotype.

 

[novatech]

The more difference you have genetically the more heterosis. This is not only true for growth but also affects fertility, milk, meat, and attitude. Along with the above mentioned fact that line breeding can expose bad traits, there will be very little heterosis as most of the genes are the same. Therefor there can be no improvement between the pair mated. The most one can hope for is what you have got. The benefit is the culling process, getting rid of those animal that express the bad traits. This leaves the cattle with the good traits that are doubled up genetically. Therefore stronger genetics that can be past on.
With mating between bos indicus and bos taurus you get maximum heterosis. But there are draw backs. One being frame jump. It is very easy to start with a 1200 lb cow and an 1800 lb. bull and end up with 1400-1600 lb. cows as your next generation. Over milk production, and bad temperament can also result with heterosis.
Line breeding should only be left to those people that really know what they are doing and have the discipline to cull properly. No barn blindness allowed.

 

[ANAZAZI]

to linebreed and cull heavily to elliminate bad traits is very expensive and slow in cattle, as compared to chickens where inbred lines are crossed to maximize heterosis.

About frame leaps when outcrossing; that brahma/blonde daquitaine bull calf we saw, it will be huge!

 

[Brandonm22]

In my experience (which is not much) I got big B.W. calves and they didnt grow. So I cant tell you about the 3rd generation as they are all gone now. I think linebreeding works well and I havent given up just need to have better foundation to start with. JHH

That is the problem with linebreeding. You have to have both the deep pockets to stick with it through those first 3 or 4 generations and sacrifice the income you would have made by outcrossing and you have to have the judgement and self control to be able to recognize when a linebreeding experiment just isn't working and jettison it and all the money, time, and work that was poured into it.

 

[HerefordSire]

To answer the question of why linebreed, maybe one should linebreed to ensure one's customer satisfaction. When one's animal is exposed to the customer's herd that is the outcross, they will benefit from your efforts. I am starting to linebreed but have not put enough time into it to really offer much "experience" on this topic. My personal purpose for linebreeding is to give my herd more exposure to a couple of my lines I am most pleased with. Just trying to make a more uniform product.

Hi Santa and Durham Reds! Excellent points. If I don't linebreed a bull and my customer buys this bull and cross-breeds to his cows, he might have one calf born at 50 pounds and another at 100 pounds. How happy is this customer going to be when he finds out he can't depend on a weight range? Gray hair is next.

 

[HerefordSire]

Really, the heterosis is the kick upwards relative the expectation of what the combination of dam and sire would perform based on their performance.

That is what we are taught. If this was the case, then we could always increase performance by continually crossing each and every generation. Sooner or later, diminishing returns has to kick in even if mating is a cross. What do you think?

Now, the natural selection and the breeding that people do to cattle; they both have a tendency to "punish" dominant "bad genes" much harder than recessive "bad genes" because of the recessive genes ability to hide behind "good" genes. Because of this tendency, most alleles that limits health, growth and performance happens to be recessive, as the dominant alleles that cause the same kind of problem.

So if I don't linebreed a bull I sell, there is a possibility a Halloweeen trick or treat could be in the customer's candy bag.

This tendency also makes it more likely that within a restricted population such as a breed, there are recessive alleles of the "bad kind" that sometimes can "come out and play", because they in a particular animal are homozygous. now figure that there are ten or a hundred such allele within a breed, this pulls down the breed average by roughly a few percent.

And in the other breed the same thing happens, however with other "bad genes" that happens to be present, but with quite the same results.

The bad kind could make me change my address so I could hide from my bull customers. Could I use a P.O. Box? :mrgreen: :mrgreen: :mrgreen:

If these two breed are crossed; it is likely that many of these "bad genes" are masked by "good genes" from the other breed.
There is only a slight heterosis effect when crossing two lines within a breed because they are likely to share most of their "crap".
When you mix hereford and aberdeen angus for example, their gene pools has been apart for a few hundred years, they are less related and tend to share less of the "crap".

We are related to moneys genetically by 95-97%?

Now, if you breed your herf to brahma bull there will be more heterosis, because the more difference in the gene pool the lees "bad genes" they will share.

How much difference in heterosis is the between a Hererford and a Taurus\Indicus?

A composite breed will have a much larger gene pool than a traditional breed, and therefore much lesser risk that one of the recessive genes "finds" a copy of "itself" and is expressed in the phenotype.

Immediate expression is good so we don't have customer surprises.

 

[Txwalt]

Once you get it into your head how breeds are created its simple to understand why heterosis exists. This probably applies to most domesticated animals.

Walt

 

[ANAZAZI]

Really, the heterosis is the kick upwards relative the expectation of what the combination of dam and sire would perform based on their performance.

That is what we are taught. If this was the case, then we could always increase performance by continually crossing each and every generation. Sooner or later, diminishing returns has to kick in even if mating is a cross. What do you think?

Heterosis is the benefit one get when fixing the microscopic holes that makes your ship leak.
The less related bull and cow are to each other, the more of the holes are fixed.
When these holes are all fixed, what else can one do?

Now, the natural selection and the breeding that people do to cattle; they both have a tendency to "punish" dominant "bad genes" much harder than recessive "bad genes" because of the recessive genes ability to hide behind "good" genes. Because of this tendency, most alleles that limits health, growth and performance happens to be recessive, as the dominant alleles that cause the same kind of problem are already extinct.

So if I don't linebreed a bull I sell, there is a possibility a Halloweeen trick or treat could be in the customer's candy bag.

No this means that the line breeder took away a few and just a few of the recessive "bad genes", thereby fixing a few of the holes.

This tendency also makes it more likely that within a restricted population such as a breed, there are recessive alleles of the "bad kind" that sometimes can "come out and play", because they in a particular animal are homozygous. now figure that there are ten or a hundred such alleles within a breed, this pulls down the breed average by roughly a few percent.

And in the other breed the same thing happens, however with other "bad genes" that happens to be present, but with quite the same results.

The bad kind could make me change my address so I could hide from my bull customers. Could I use a P.O. Box? :mrgreen: :mrgreen: :mrgreen:

If these two breed are crossed; it is likely that many of these "bad genes" are masked by "good genes" from the other breed.
There is only a slight heterosis effect when crossing two lines within a breed because they are likely to share most of their "crap".
When you mix hereford and aberdeen angus for example, their gene pools has been apart for a few hundred years, they are less related and tend to share less of the "crap".

We are related to moneys genetically by 95-97%?

Monkeys? God forbid. Never mind, if the outcoss is too great, problems will occur in the cooperation of different sets of chromosomes. The barrier between species.

Now, if you breed your herf to brahma bull there will be more heterosis, because the more difference in the gene pool the less "bad genes" they will share.

A composite breed will have a much larger gene pool than a traditional breed, and therefore much lesser risk that one of the recessive genes "finds" a copy of "itself" and is expressed in the phenotype.

Immediate expression is good so we don't have customer surprises.

The good genes from the composite bull will hide the "bad genes" from the customers cows, and calves will be fine, in fact healthier than their dams, wich, being purebreds express more weaknesses.

 

[TxStateCowboy]

I'm a South Texas German boy married to a Fort Worth Mexican gal. Our children will be able to hunt AND cook. :cboy:

Linebreeders develop consistent cattle with certain traits,
For cattleman to select according to their geographical needs,
To produce beef cattle,
For packers and butchers to slaughter to produce....

The greatest meat product on earth, always better than chicken and pig.


If everyone linebred all the time, we wouldn't know what better cattle were because they'd all be the same, with the same problems and benefits.
If everyone crossbred all the time, we'd have such a pile of junk we wouldn't be able to solve geographical problems (angus do better up north, brahma do better down south, longhorns do better if all you have is rocks and mesquites).

I like purebred, even if linebred, bulls on top of crossbred cattle that meet my geographical/operational needs.

-Will

 

[BC]

Linebreeding develops consistency, so that when you cross the linebred animal out you get a shot of hybrid vigor within your breed.

I have seen this done in several breeds:
Santa Gertrudis - the influence of Hustler 920 when mated to TT 22 cow. That cross worked 20 years ago and still has influence today. For old timers that can remember some of the old John Martin breeding a bull called Primo 312.

Brahmans - a bull named GBW Wrinles Manso III 207/6. Here is link to his pedigree:
http://www.brahman.org/searches.html ABBA # is 274985. He goes back to the same bull all 4 times in the 3rd generation. This bull really produced some outstanding females.

Other Brahman bloodlines that come to mind are the Imperator, Sugarland Rexcrata and Cherokee Vernon.

Herefords: Line Ones, Real Onward

 

[ANAZAZI]

I would say linebreeding a composite is not great because one of the reasons for composites are the retained heterosis.

 

[Brandonm22]

Hi Santa and Durham Reds! Excellent points. If I don't linebreed a bull and my customer buys this bull and cross-breeds to his cows, he might have one calf born at 50 pounds and another at 100 pounds. How happy is this customer going to be when he finds out he can't depend on a weight range? Gray hair is next.

Linebreeders like to claim that their stock will have less variation in measurable production traits than standard outcross stock of the same breed when used in a commercial crossbreeding situation; but somebody would have to show me actual scientific research showing that to be true for me to accept that as anything but conjecture. I am not disagreeing with the theory; just am not convinced that it is valid.

 

[novatech]

Linebreeders like to claim that their stock will have less variation in measurable production traits than standard outcross stock of the same breed when used in a commercial crossbreeding situation; but somebody would have to show me actual scientific research showing that to be true for me to accept that as anything but conjecture. I am not disagreeing with the theory; just am not convinced that it is valid.

http://digitalcommons.unl.edu/cgi/viewc ... eefcowsymp