# Linebreeding pigs



## lasergrl (Nov 24, 2007)

I have been reading what I can about pig breeding ect. I have come across a few articles that claim linebreeding in pigs will cause 10-50% birth defects and stillbirths. This doesnt really make much sense to me. Why should pigs be so different from other species in this respect? I have a line of rats that is linebred/inbred for the past 6 generations, with carefull breeding they are as normal as any other rats.
Is it ok to breed half brother to half sister. Same boar, but from different sows?

Tiffan


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## RedHogs (Jul 7, 2006)

Line breeding first shows up in the first 24 hours, a heavy line bred hog is just slower to get sucking, the 21 day weights are also down alot also, The mulefoot or double dew claw will show up eventually, I've had one mulefoot out of purebred durocs....I culled it and moved on. That being said the slow start is often refered to as a defect and it is a problem without very careful management. I believe that is what they are talking about.


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## highlands (Jul 18, 2004)

Pigs are great for line breeding. They reproduce quickly, have over two litters per year, each litter is many young and they grow rapidly - almost as good as mice and rats. We've had no problems from line breeding. Only about 1 in 500 boars typically will get bred and only about 1 in 100 gilts - Just select the best of the best in each generation aiming for your goal pigs. This quickly weeds out bad genes. Culls go to dinner.

Cheers

-Walter
Sugar Mountain Farm
in the mountains of Vermont
http://SugarMtnFarm.com/blog/
http://HollyGraphicArt.com/
http://NoNAIS.org


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## PETSNEGGS (Oct 7, 2005)

Lasergrl thanks so much for asking that... I have been wondering all about that too....when you are talking about line breeding, can I keep one of my piglets ( female) and let her breed with her father or is that a huge NO NO? I just have one male and one female right now that had piglets. Would like to add to the group but, didn't want to have breeding problems.


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## RedHogs (Jul 7, 2006)

What is the purpose of your Line breeding???? 

Line Breeding is really only used in very tight breeding farms with registered hogs. I am never a fan of breeding inward because of simple easy availabilty. With the low cost of AI and the ease of purchasing quality genetics, your herd could be quickly improved with a dose of AI. I have always used linebreeding to maintain a tight maternal line, replacing and tightning my maternal traits, so that the outcross litters haver super hybrid vigor....The line breeding produces a 1 linebred sow that is outcrossed 7-8 times. The purpose of having an *in*litter is to magnify the next breeding.....The goal of line breeding is never the litter that is produced....It is the litter produced in the next outcross from the linebred sow or boar. If you goal is to produce market hogs, linebreeding is definately a waste....Outcrossing will produce better 
piglets.....


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## highlands (Jul 18, 2004)

Some good purposes of linebreeding:

1) Expressing traits from a set you have.

2) Closed herd.

3) Limited availability of breeders - e.g., you have what you have and you want to work with it rather than spending money and resources buying and maintaining another boar, AI, etc. Perfectly good reason.

Line breeding won't produce monsters. It will inexpensively let you breed. You can do it for generations, just cull to the dinner plate.

Whether your hogs are registered or not has little to do with the choice.

Cheers

-Walter
Sugar Mountain Farm
in the mountains of Vermont
http://SugarMtnFarm.com/blog/
http://HollyGraphicArt.com/
http://NoNAIS.org


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## tyusclan (Jan 1, 2005)

Every breed of domestic animal we have today is a result of inbreeding/linebreeding. In the hands of an experienced breeder with specific goals in mind, inbreeding is a valuable tool. In the hands of a novice or someone without the experience it can be a disaster.

Having said that, breeding father to daughter is usually not a problem, especially if the boar is unrelated to the sow the gilt came from. Inbreeding does one thing, intensifies the traits of the stock by limiting the gene pool. Both GOOD and BAD traits are intensified. If you do breed father to daughter, choose the very best daughter from the litter, and cull ANY undesirable trait. If there's a trait that you don't like in either of the parent animals, that trait will likely show up much worse in the offspring.

If I had a decent daughter and needed a sow to raise a litter, and I were planning to butcher the entire litter anyway, I'd probably give it a try. You're not going to have a catastrophe in the first cross back to a sire.


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## lasergrl (Nov 24, 2007)

what about the half sibling scenerio? Assume growth rate is insignificant at this point.


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## tyusclan (Jan 1, 2005)

A half-sibling breeding is actually not as close genetically as father to daughter breeding.

With a father/daughter breeding the offspring would be genetically 75% the sire.

With a half-sibling would only carry 50% of the genetics of the common parent.


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## RedHogs (Jul 7, 2006)

> what about the half sibling scenerio? Assume growth rate is insignificant at this point.


This not line breeding, it is what many call _rounding_)when you use siblings)....I have never used it, it will definately lower your growth rate.

What is your current rate of gain.... If its over 150 days, you don't have the genetics to linebreed.....You must have quality genetics to build upon....Why not get one super good purebred sow and breed from there....It takes the same feed, time, and energy to farrow a quality litter as a junk litter.


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## lasergrl (Nov 24, 2007)

I am talking mini pigs here, rare breed, only a handful have them. So, growth rate is not significant. Main conscern is that I have been reading that it will cause birth defects. I understand genetics pretty well, so, didnt make sense to me. If you start with healthy stock, and cull, there should be good results. These pages I have been reading, pertain to "pet" hogs, and perhaps culling is out of mind in these cases. I have no problem with it. If there is a problem with the offspring they still make meat, just less!


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## PETSNEGGS (Oct 7, 2005)

Very interesting and thanks for the lesson.


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## gimpy (Sep 18, 2007)

lasergrl said:


> what about the half sibling scenerio? Assume growth rate is insignificant at this point.


If the progeny is going in the freezer it probably wont matter much. Try it and if you dont like the result get some fresh blood


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