Do any of you have any experience with DELIBERATE inbreeding? I don't mean the "bull got into the pasture with his daughter" type, but the "I did it on purpose" type. I've heard academics warn against "inbred depression" but breeders I've read about say they don't see it. Maybe they don't want to see it! I suspect that inbreeding is Nature's way of setting a genotype and eliminating undesirable recessives.
inbreeding
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Ebenezer
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Inbreeding is fine if you have a purpose. Use phenotypic selection to minimize depression or regression.
Muddy
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Pay attention to the performance of the offspring. If they do poor, change bulls.
Inbreeding depression exists in the way it is measured. Four generations of full sibling matings with random choice of breeding specimens, it has been replicated with lots of different species such as swine, dogs, guinea pigs, rabbits, you name it. It has to be random to be replicable, if not replicable not science. Outside of the laboratory it is not that easy to find, due to the fact that neither nature nor farmer select their breeding stock at random. Inbreeding without culling is not a wise move, with culling it is not that bad. Usually there is more culling with close breeding than with outbreeding for a few generations.
There are three obvious risks with inbreeding: 1, Inbreeding depression (like noted not a great problem under sensible culling),
2. exposing genetic defects (like snorter dwarfs, CVM and such), which can be either good or bad depending on the setting (bad because many progeny needs to be eutanized, good because it is a way of cleaning certain parts of a breed from defects for later), and
3.the risk of genetic drift that might be a problem in the long run using to few males but not allowing that problem to be remedied by "new blood". In a multi sire setting like my own, or like for example the Lasater ranch, there are enough sires that random loss of genetic information due to genetic drift is a non issue.
There are three obvious risks with inbreeding: 1, Inbreeding depression (like noted not a great problem under sensible culling),
2. exposing genetic defects (like snorter dwarfs, CVM and such), which can be either good or bad depending on the setting (bad because many progeny needs to be eutanized, good because it is a way of cleaning certain parts of a breed from defects for later), and
3.the risk of genetic drift that might be a problem in the long run using to few males but not allowing that problem to be remedied by "new blood". In a multi sire setting like my own, or like for example the Lasater ranch, there are enough sires that random loss of genetic information due to genetic drift is a non issue.
sim.-ang.king
Well-known member
Get right man, it's linebreeding if it works, it's inbreeding if it don't.
City Guy":1s2baf07 said:
Genetic drift is the change in the frequency of a gene variant (allele) in a population due to random sampling of organisms. The alleles in the offspring are a sample of those in the parents, and chance has a role in determining whether a given individual survives and reproduces. The more even the quota between the sexes and the bigger the population the less genetic drift. We want genes to be lost from our population due to culling, not by randomness.
There is no test that works for everything. Tests are trait specific. The only sure method to know that a bull is free from any and all defects is to breed him to 35 of his daughters, without any progeny affected by any genetic disorder.
I had a cow who produced 2 dinks out of a reg angus. She was mostly sim, out of a sim cow and a sim/angus bull. Really nice cow but when she appeared to be open at the end of the season, i moved her into the old herd to cull later at weaning. She surprised us and calved very late, with a calf that did ok, but was still not a quality calf. This was 2014 i think and as prices soared, we did not cull her as long as she popped out a calf. Later on, ding ding ding, i realized that the bull she was with was her half brother. To late to move her so i just let happen with what happened. She had the best calf ever, was one of the highest sellers.
Ebenezer
Well-known member
The problem that is described here of "point of no return" is a breeder's error and not a multisire or single sire issue. Watch phenotype on every generation and you will not get down the drain before you realize that all is lost.
You merely identified a bull or a line that should not be linebred.
Ol' 243
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Here in Alabama you don't see it just in cows, you should see some of these sumbitches running around here. 
M-5
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Ol' 243":wl61hk6w said:Here in Alabama you don't see it just in cows, you should see some of these sumbitches running around here.
tell your sistercousinwife I said Hello.
talltimber
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:lol: :lol:Ol' 243":j6d90nz9 said:Here in Alabama you don't see it just in cows, you should see some of these sumbitches running around here.
Nesikep
Well-known member
My cow must be from down south, she's had 3 calves, from 3 sires.. One was her father, the other was her brother... slut!
Her calves all look good though.
I'm experimenting a little with linebreeding with sons from an exceptional cow, I expect slightly less growth from the lack of hybrid vigor, but with more consistency. I'm just at the size where 1 bull is at his limit, but 2 bulls is somewhat overkill, So as insurance I have 2, one of my own, and one from outside, if any of them fail, I have a backup plan and still get calves. So far I'm happy with the calves I have from my own bull, he didn't breed the best cows last year so the calves are smaller, but they're built nicely, next year he'll have calves from a better group of cows, and perhaps there will be some replacement quality stock there, I'd be particularly interested in a linebred bull calf, perhaps from his full sister.
Her calves all look good though.
I'm experimenting a little with linebreeding with sons from an exceptional cow, I expect slightly less growth from the lack of hybrid vigor, but with more consistency. I'm just at the size where 1 bull is at his limit, but 2 bulls is somewhat overkill, So as insurance I have 2, one of my own, and one from outside, if any of them fail, I have a backup plan and still get calves. So far I'm happy with the calves I have from my own bull, he didn't breed the best cows last year so the calves are smaller, but they're built nicely, next year he'll have calves from a better group of cows, and perhaps there will be some replacement quality stock there, I'd be particularly interested in a linebred bull calf, perhaps from his full sister.
Ol' 243
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M-5":3nt41vbj said:Ol' 243":3nt41vbj said:Here in Alabama you don't see it just in cows, you should see some of these sumbitches running around here.
tell your sistercousinwife I said Hello.
She say's to hurry back to see her, she misses you. :lol:
M-5
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I'll be there shortly Daddy.
Muddy
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Because your animals are not enough "inbred" due to different bloodlines and breeds you used on your cattle. Huge genepool and not very tight consistency in your cattle. Next calf may will be dink again, or may be an average calf.cowgirl8":bujlmiq6 said:
My question was for Ebenezer....since you have no idea how our business is run, you are not qualified in any way in making any statements or answering my question... Cow this year was bred to her brothers son which would make a nephew, had a nice calf again. It is different though, a heifer...lolMuddy":18oarmh5 said:
Ebenezer
Well-known member
Hate to say this, but when you post something on a chat site do you think the ones who read and posts are PhDs who know you and your management? A random one calf is no test but your cow proved herself as a dink producer before you bred her to her nephew for about a 12.5% IBC or whatever IBC it is. It is a minimal amount of inbreeding especially from a recent breed cross.
Just to give you an idea of background, I have a strain of a breed of chickens here for pleasure and learning that has been linebred since the 60s. The closed sheep flock started with half sibs or stronger IBCs, the lines in the flock are continued to be built on either sire/daughter or dam/son lines and can be used for linebreeding or line crossing. No sheep people here but we are at zero need to worm and can get average lamb carcasses at 50%+ HCW/LW and all with no hands on pasture lambing.
The bull currently with the cows is about a 1st cousin/1st cousin mating or closer, 5 sons wait to be used in coming years on half sisters and such based on a 50+ year old cattle learning curve and herd, the bull with the heifers is a full brother/full sister mating. He is breeding some daughters. The cows are adapted to KY 31 fescue due to generations of selections. The 7 YO bull with the heifers can run and jump like a spring calf just like the 6 YO bull with the cows, the sheep are improving, the chickens are laying better than ever without faults and such as that. So, you can cull my comments as I have no understanding of your circumstances.
City Guy":1vrr2wgl said:
My comment was directed to the OP..
I had a cow who produced 2 dinks out of a reg angus. She was mostly sim, out of a sim cow and a sim/angus bull. Really nice cow but when she appeared to be open at the end of the season, i moved her into the old herd to cull later at weaning. She surprised us and calved very late, with a calf that did ok, but was still not a quality calf. This was 2014 i think and as prices soared, we did not cull her as long as she popped out a calf. Later on, ding ding ding, i realized that the bull she was with was her half brother. To late to move her so i just let happen with what happened. She had the best calf ever, was one of the highest sellers.
How linebred breeding got all tangled up in my comment, it wasnt me. Although, line breeding starts somewhere, and the bulls we keep are out of a line we want to keep in our herds so if we wanted to we'd do it with these bulls. But, technically, my comment was for the OP. Found it unusual that a cow after 2 dink calves pops out a winner bred to her brother...We dont like inbreeding and do what we can to keep it from happening. But, like some think, the calves dont come out with extra ears or 5 legs...lol
