Linebreeding

[MikeC]

What could be expected by breeding a son to the dam?

The only time I've had that mistake happen was a complete trainwreck.

details please.

Was holding a cow (a very good cow, I might add) and her calf in a trap close to the barn for some reason (don't exactly remember why). Anyway, her son (the year before) was in another trap next to her. One morning when I went to feed, her son was in the pen with her. I saw no signs of the cow cycling so I just got him out and made a note of it.

When the cow calved the following fall, she was early........ obviously bred to her son by my breeding date records.

The calf wasn't quite right, I could tell by looking at her. The older the calf got, the more pronounced her physical and mannerisms, such as - she had a very narrow nose and mouth, she always held her head down, abnormally long ears, she had a very curious trot when she moved, almost like a bouncing gait and was always thinner than the rest of the calves in the pasture. She little tiny feet and legs too.

One of my neighbors who helps me often referred to her as "retarded".

My helper - "Willie" referred to her as "Flicted" :lol:.

When the calf got about 6 months old and 400 lbs., much lighter than her contemporaries, I let her take a ride to the sale barn. She only brought about $60 because of her looks.

I would never breed a son to his dam. If you had seen this calf you wouldn't either.

Mike,
All that means is that there are some non-desirable genes in that particular cow. Inbreeding just brought them to the surface. Did you keep her son as a breeding bull after that? He did contribute 1/2 of the "retarded" calf's genetics.

Yes, I realize their were undesirable genes somewhere. But you COULD NOT look at either the cow or her son and know they were there. They were as perfect "Phenotypically" as any I have ever had.

No, I sold the bull (son) to a commercial breeder. The cow stayed around for several years afterwards, and gave me a total of 12 calves, some daughters are still here, which were all good stock except that one.

I forgot to mention earlier that the heifer I sold was dumb as a rock. She would run right into a fence as though it weren't there, get right back up, and do it again.

 

[Aero]

Yes, I realize their were undesirable genes somewhere. But you COULD NOT look at either the cow or her son and know they were there. They were as perfect "Phenotypically" as any I have ever had.

a perfect example of the usefulness of linebreeding. if that cow has enough influence (coupled with some bad luck), you could have that same calf all over again even though it looks to be an "outcross" mating.

 

[KMacGinley]

It is much more likely that her condition was a result of environment than genetics. Maybe a pinched cord.

 

[Badlands]

Mike,


This is one of those times you wished your buddy wasn't the one to make an example of. ;-)



Your animal illustrate perfectly why we should be practicing some level of linebreeding in the purebred herds.

Your cow had some genetic trash of some sort.

A linebreeder would cull such an animal and maybe even all progeny. If any sons were saved from such a cow, he would be bred to his half-sisters or daughters to test how much junk was in him.

If the traits manifested themselves in him, he would be culled to.

Badlands

 

[MikeC]

Yes, I realize their were undesirable genes somewhere. But you COULD NOT look at either the cow or her son and know they were there. They were as perfect "Phenotypically" as any I have ever had.

a perfect example of the usefulness of linebreeding. if that cow has enough influence (coupled with some bad luck), you could have that same calf all over again even though it looks to be an "outcross" mating.

That cow had me 11 other calves that were good solid stock.

Her daughters, 3 or 4 at guessing, have not had any undesireables.

I'm not totally against linebreeding, we have done it for years. I'm just saying when you match a son to his dam you can have a problem. That's what I describe as "Inbreeding".

Like I said earlier, 1/2 sibs to 1/2 sibs is as close as I'll get anymore. And even then you can see some degradation in growth traits.

 

[MikeC]

It is much more likely that her condition was a result of environment than genetics. Maybe a pinched cord.

Not a chance.

 

[Aero]

MikeC:
do yall produce seedstock or feeders mainly? linebreeding is pointless and counter-productive in feeders.

my definition of linebreeding isnt as restrictive as some. if you plan it and have a purpose, it's linebreeding. if it's an accident, undesirable or because you have no other bull, it's just breeding with a higher inbreeding coefficient.

 

[Aero]

And even then you can see some degradation in growth traits.

you are actually seeing the true genetic level of the animals with much less outcross-effect/heterosis.

 

[MikeC]

And even then you can see some degradation in growth traits.

you are actually seeing the true genetic level of the animals with much less outcross-effect/heterosis.

I think what I have seen is "inbreeding regression".

 

[KMacGinley]

It is much more likely that her condition was a result of environment than genetics. Maybe a pinched cord.

Not a chance.

Really? I would think that if you really believed what you are claiming, none of that blood would exist in your herd anymore if you understand anything of genetics.

 

[MikeC]

Extreme inbreeding may be avoided in any linebreeding program by not mating fathers to daughters or siblings to each other (or other similar matings that involve close relatives). However, the degree of inbreeding is related not just to the immediate relationship between the two mated individuals, but also to the degree to which these individuals were already inbred. For instance, if a particular bull is widely used in a linebreeding program, then many of the cattle in that program will already share the genes of that bull, and the chances of getting two deleterious alleles from that bull in the same offspring are greatly increased. The chances may not be as great as would occur between the matings of siblings, but they are much higher than would occur in a randomly mating population. Even small increases in inbreeding result in some inbreeding depression. For instance, just a 1% increase in inbreeding (that is, a 1% increase in the probability that a calf receives the same gene from both parents) results in a measurable decrease in milk quantity and quality, shortening of productive life, and increase in calving interval in studied breeds of cattle.

 

[KNERSIE]

Aren't we neglecting to mention the advantage that can be gained by fixing the traits you select for in your herd for future generations as well as getting rid of the unwanted traits by selecting against it and so getting your herd to a more uniform higher level?

If you are going to linebreed you have to weigh up the potential long term advantages of linebreeding compared to the short term vigour from outcross breeding without ever moving your herd up to the next level of uniformity.

If your linebreeding venture fails it is because your selection protocols failed you. The same goes for outcrossing, but the effect won't be as pronounced with outcrossing.

 

[Julian]

Aren't we neglecting to mention the advantage that can be gained by fixing the traits you select for in your herd for future generations as well as getting rid of the unwanted traits by selecting against it and so getting your herd to a more uniform higher level?

If you are going to linebreed you have to weigh up the potential long term advantages of linebreeding compared to the short term vigour from outcross breeding without ever moving your herd up to the next level of uniformity.

If your linebreeding venture fails it is because your selection protocols failed you. The same goes for outcrossing, but the effect won't be as pronounced with outcrossing.

Very well put!
--Julian

 

[MikeC]

Effect of Inbreeding in a Seed stock Herd
Inbreeding is nearly unavoidable in seed stock herds since it is frequently difficult to find new breeding stock that are not, at least partially, related to animals in an existing herd. Care should be taken to keep inbreeding at a fairly low level by avoiding matings of brothers with sisters or parents with their offspring. Close matings within small herds or family groups not only produce rapid inbreeding buildup and, hence, depression, but can produce random losses of desirable genes.

If inbreeding builds up, the first economic effect will be fewer calves available to sell. In addition, the calves will have poorer performance and will not be as attractive to customers interested in performance

 

[Aero]

I think what I have seen is "inbreeding regression".

and what will this regression take you to?

regression is just a name for the process of moving to a certain value.



here is something i am researching at the moment.

imagine you could have an animal where all of the animals in the pedigree were the same animal. i am pretty sure this animal would have an inbreeding coefficient (IBC) of 100%. measure a large group of full sibs for any trait and the average should be the true genetic level of the animal for whatever trait you are measuring.

this isnt a realistic scenario, but you can estimate true genetic level with IBC.

if growth is something you are concerned about and you want to have parent stock that actually has a higher true genetic level of growth, use the inbreeding coefficient to help estimate.

say you have a group of full sibs with an inbreeding coefficient of 0.0% and their average weaning weight is 600 lb. if you breed the sire (Sire A) to his daughters (25% IBC) and the average weaning weight goes to 500 lb. => 100 lb inbreeding depression.

another unrelated group of full sibs weans 600 lb at 0.05 IBC.
at 25% IBC (Sire B) they too wean at 550 lb. => 50 lb inbreeding depression.

which sire would you say has a higher true genetic level for growth? this should be some type of 1/(Ae^X) function where A represents the effect of heterosis and the limit as X approaches infinity will be the true genetic level.

X represents IBC - 0 = 0.0%, 10 = 100%
Y represents weight in lbs.

what's the usefulness in this particular scenario? i am not sure yet.

excuse me for getting carried away. again, this isnt proven data, just what is going on in my head.

 

[Aero]

If your linebreeding venture fails it is because your selection protocols failed you.

or you started with hopelessly bad stock to begin with.

 

[Julian]

Effect of Inbreeding in a Seed stock Herd
Inbreeding is nearly unavoidable in seed stock herds since it is frequently difficult to find new breeding stock that are not, at least partially, related to animals in an existing herd. Care should be taken to keep inbreeding at a fairly low level by avoiding matings of brothers with sisters or parents with their offspring. Close matings within small herds or family groups not only produce rapid inbreeding buildup and, hence, depression, but can produce random losses of desirable genes.

If inbreeding builds up, the first economic effect will be fewer calves available to sell. In addition, the calves will have poorer performance and will not be as attractive to customers interested in performance

MikeC,
I am curious who you are quoting/referencing. I can provide numerous quotes by Lush and Hagedoorn that put linebreeding in a positive light.
--Julian

 

[KNERSIE]

I would also like to know.

Do anyone have any good links to linebreeding research, by any chance?

Good info and not biased opinions either way are hard to come by when it comes to linebreeding.

 

[MikeC]

Effect of Inbreeding in a Seed stock Herd
Inbreeding is nearly unavoidable in seed stock herds since it is frequently difficult to find new breeding stock that are not, at least partially, related to animals in an existing herd. Care should be taken to keep inbreeding at a fairly low level by avoiding matings of brothers with sisters or parents with their offspring. Close matings within small herds or family groups not only produce rapid inbreeding buildup and, hence, depression, but can produce random losses of desirable genes.

If inbreeding builds up, the first economic effect will be fewer calves available to sell. In addition, the calves will have poorer performance and will not be as attractive to customers interested in performance

MikeC,
I am curious who you are quoting/referencing. I can provide numerous quotes by Lush and Hagedoorn that put linebreeding in a positive light.
--Julian

That particular quote came from an Oklahoma State article.

I didn't think it was negative. Just showing how overdoing a good thing can send you program awry.

http://www.thebeefsite.com/articles/755 ... -in-cattle

 

[phillse]

I believe Jim LEnts put it best on linebreeding in his book "Principles of Linebreeding"; he said the key to linebreeding was unrelenting culling during the 1st, 2nd and 3rd generation of linebreeding. THIS in effect cleansed the herd and left a good herd.


AS for LIne breeding, I Have bred half sibs 6 times and I have bred grand sire to granddaughter 2 times. IN regard to growth on the half sib mating 1 was trash, three were superior and 2 were average.

In the grandsire to granddaughter the 2 calves were great they actually out performed the outcross calves on growth.

With LINEbreeding you keep the best and cull the rest, the same as you should do with any breeding program.