Breeding Terms

[buckaroo_bif]

Yes, that's the guy who wrote the book Jim Lents.

I am going dig it up again and refresh my mind.

Must be quite a good book cause I got ahold of Jim and he said he is sold out right now. I am ordering one of Gerald Fry's books for now and am on Lents waiting list.

 

[Victoria]

I was reading up about this awhile back. Most of the sites I looked at say that inbreeding is breeding involving close relatives - including parent/offspring, brother/sister, half-brother/half-sister. Line breeding is more distant relatives breeding.
I wrote a geneticist friend of my husband's and got this e-mail back about it all. I hope it helps clear things up for you, it did for me:

When a mother and a father have a baby, that baby has two sets of genes
one from each. Let's play a little game and pretend that healthy genes
are capitalized and unhealthy (mutated or for other reasons) genes are
lower case. Say the mother has genes:
>>>> Aa
>>>> BB
>>>> Cc
>>>> Dd
>>>> EE
>>>> FF
>>>> GG
>>>> HH

And the father has the genes:
>>>> AA
>>>> BB
>>>> CC
>>>> DD
>>>> EE
>>>> Ff
>>>> Gg
>>>> HH

Then we know exactly what genes the baby, who gets one copy of one half of each, can have -- thogh there are already a lot of combinations (bear in mind this is a game, the real human genome has billions of these, and even though all combinations can be mathematically predicted, in reality no
one can ever do that).

>>>> AA
>>>> BB
>>>> CC
>>>> DD
>>>> EE
>>>> FF
>>>> GG
>>>> HH

or

>>>> AA
>>>> BB
>>>> CC
>>>> DD
>>>> EE
>>>> Ff
>>>> Gg
>>>> HH

or

>>>> aA
>>>> BB
>>>> cC
>>>> dD
>>>> EE
>>>> FF
>>>> GG
>>>> HH

or

>>>> aA
>>>> BB
>>>> cC
>>>> dD
>>>> EE
>>>> Ff
>>>> Gg
>>>> HH

You'll notice that some of these are exactly the same encodings, but that doesn't matter to us, it only doubles the probability that the baby will inherit those copies. All that matters to us is that the baby never got two copies of a bad gene. Also notice that 1 in 4 babies managed to get away without any latent problems at all and is perfect!

Now, genes encode both materials and processes within the body, and as long as one copy of a gene is good you're fine. But look what happens if the mother and father are actually
brother and sister:

Now the mother has genes:
>>>> Aa
>>>> BB
>>>> Cc
>>>> Dd
>>>> EE
>>>> FF
>>>> GG
>>>> HH

But the father, her brother, has the genes:
>>>> Aa
>>>> BB
>>>> Cc
>>>> DD
>>>> Ee
>>>> FF
>>>> GG
>>>> HH

Notice that since they are closely related they have similar encodings. Here're the baby's odds:

>>>> AA
>>>> BB
>>>> CC
>>>> DD
>>>> EE
>>>> FF
>>>> GG
>>>> HH

or

>>>> Aa
>>>> BB
>>>> Cc
>>>> DD
>>>> Ee
>>>> FF
>>>> GG
>>>> HH

or

>>>> aA
>>>> BB
>>>> cC
>>>> dD
>>>> EE
>>>> FF
>>>> GG
>>>> HH

or

>>>> aa
>>>> BB
>>>> cc
>>>> dD
>>>> Ee
>>>> FF
>>>> GG
>>>> HH

Notice the fourth combination, which has a 1 in 4 chance of occuring. While the baby got lucky with a working copy of genes D and E, it does not have a and c, and will probably die or worse. This happens to 1 in 4 babies.

On the other hand notice that now the odds of having a perfect baby has gone up to 1 in 3 (only because one in 4 don't make it).

So the Egyptian royal family, after thousands of years of marrying brother and sister, were thought to have the cleanest and most perfect genes in the history of the world, but they paid a terrible price for it.

And this will happen to cows. The closer you breed them, the more problems will come out, but the ones that make it may end up cleaner in the end.
There is no math here, you have to see what others have done, and if you want to try it, expect a lot of tragedies. Hope that helps.

 

[buckaroo_bif]

Thanks Victoria,
I got an e-mail back from Jim Lents when I requested his book and here is what he said about coefficients
quote>


As for coefficients of inbreeding I pay them no attention as they have nothing to do with linebreeding stock. They are mostly used as fear factors to scare people off of linebreeding. One thing is certain though, until you build up a little coefficient of inbreeding you don't have much in the way of prepotency to carry on with. Outcrossing and crossbreeding are similar and related. Here's how, Linebreeding builds up a homozygous state for all characteristics and makes them dominant. It creates homozygous genepairs i.e., identical allelles thus the animal possess prepotency. Prepotency is the ability of a parent to forciably stamp their characteristics onto their offspring uniformly. Outcrossing is the mating of unrelated animals within a breed, and is the first step to breaking down a homozygous state and converting control of characteristics to recessive genetic combinations. Crossbreeding is the final step in the destruction of a homozygous state and is always achieved via the crossing of two parents of different breeds or crosses. I wouldn't worry too much about ending up in trouble when you close your herd. Just recognize that there will be some unraveling and some animals will be unacceptable for your purposes. they will be just fine for others in the marketplace so you will be just fine. the further you go, the fewer unacceptable animlas you will produce. Of course this all hinges on your selection . It must be constant and for a consistent set of criteria. In other words you need to know what you want to produce before you start and not waver. Hope this helps you.
Jim

 

[Workinonit Farm]

This has been a really interesting thread. Thank you to everyone who have helped with the education on this.

Katherine

 

[buckaroo_bif]

This has been a really interesting thread. Thank you to everyone who have helped with the education on this.

Katherine

you're welcome Katherine

 

[Victoria]

Interesting e-mail buckaroo_bif. I find it interesting how much information I have found on this subject and how many different opinions are.
I'd love it if you would continue posting on this as you learn more as this is something I would also like to learn more about.

 

[buckaroo_bif]

Ok I am still not very knowledgable on this subject so as not to lead people astray I am pasting part of another e-mail. This particular letter points out the benefits form linebreeding.

quote>
Linebreeding is the mating of relatives with the full intent and purpose of concentrating the inheritance of a particular superior ancestor. Therefore, linebreeding is inbreeding, but a very controlled form of inbreeding with specific purpose in mind. It takes extreme dedication, discipline and hard selection & Culling to be a successful linebreeder. That is why most seestock producers cannot do this well. When you examine the history of any of the breeds, they were all developed through elite breeders who were true artists at linebreeding. There are no elite herds that were not developed without the use of linebreeding. It is designed to concentrate the inheritance of superior ancestors. Therefore, you are making many pairs of genes homozygous dominant, thus assuring that the linebred sire can only pass down one form of a gene to his offspring. That is what makes them so prepotent (the ability of a sire to "stamp" his characteristics on his progeny to a high degree). Outcross seedstock cannot do this. We select seedstock that are linebred and possess the characteristics needed for our criteria. That does not mean that all linebred cattle are superior. You can linebreed crap, as well as good stuff.

 

[buhbuh]

Breed the best to the best. Cull the rest.

 

[DOC HARRIS]

So the Egyptian royal family, after thousands of years of marrying brother and sister, were thought to have the cleanest and most perfect genes in the history of the world, but they paid a terrible price for it.

And this will happen to cows. The closer you breed them, the more problems will come out, but the ones that make it may end up cleaner in the end.
There is no math here, you have to see what others have done, and if you want to try it, expect a lot of tragedies. Hope that helps.

This is as succinct an explanation as I have seen. Because of the literally BILLIONS of genes involved in mating Male A to Female B, we are playing with dynamite when we indiscriminately mate animals on the basis of looks - ONLY -! Inasmuch as there are more possiblities of genetic errors occurring when multiple traits are being considered, it is understandable why some supposedly "fail proof" matings :roll: don't display the results we would expect! There are always TWO sets of genes being combined, and that is the primary reason why careful consideration should be given to EACH mating. It's our BUSINE$$ - not just fun and games. ;-)

DOC HARRIS

 

[Brandonm2]

"So the Egyptian royal family, after thousands of years of marrying brother and sister, were thought to have the cleanest and most perfect genes in the history of the world, but they paid a terrible price for it."

Of course, the Egyptian royal family did not cull either. Persons who were VERY deformed actually were allowed on the throne and too reproduce. The great Germanic line of kings, the Merovingians, did the same thing and ended up with many (literally) retarded individuals on the throne in its final couple of centuries. Linebreeding works best for breeders who are willing to cull aggressively. If you don't have the ability, the deep pockets, or the cold realism needed to accept failure and cull out a whole cow family or two, you would be better off not linebreeding.

 

[cypressfarms]

With Arabian horses, people actually list their pedigrees along with the percentage of "superior" horses as well. As an example, Ansata Ibn Halima is accepted to be a great Arabian stallion in all aspects, but he's long since dead. Breeders will breed certain horses to others to try to concentrate more of his blood in offspring (or for any other horse they may want). Using this version of linebreeding, to me, is not only acceptable, but gives the breeder more phentoypically similar foals. Now, of course, cattle and horses are very different, but I think the same principle can be applied, if a certain phenotype is desired. However genetically, the more similar (or closer the blood) the cattle, it stands to reason that there would be less growth associated with diverse genetics. Something that the horse world does not have to worry about: if the foal winds up 15.5 hands or 16 hands, will make it no less valuable. However, this fact is extremely important with cattle, as most cattle farmers are concerned with pounds weaned.

 

[buckaroo_bif]

Good feedback guys, thanks!