How To Get Started With Selective Breeding?

Hi, everyone! A friend of mine has experience in caring for pigs, but she's mostly just raised small herds of weaners for meat. I'm looking into learning and working with her on expanding her pig operation (to our mutual benefit), but neither of us have experience in breeding.
We've mostly dealt with Berkshires, but we'd be interested in perhaps going into crossbreeds that still produce good marbling, but have a white (or mostly white) skin. Yorkshire/GOS/Berkshire crosses?

I'm looking for information and recommendations on how to start our own breeding stock, and the process involved in keeping good bloodlines. How much inbreeding/line breeding is acceptable? How do we reliably keep specific traits if we have to keep changing one or both of the parents? I'm afraid I really don't understand how these things work at all.

What would be the most basic breeding scheme to help us newbies get started?

you can keep a daughter and breed her to the boar that's as far that's safe to keep inbreeding to a low

I am studying animal genetics at university so I would love to give you some advice.

Cross breeds have hybrid vigor. This makes them an excellent choice for meat production, the only downside to crossbreeds is that it is difficult to sell them as breeding stock.

A simple crossbreeding scheme might look like this:
sow A is a Yorkshire bred to boar B who is a GOS
they produce female AB (50/50 Yorkshire/GOS) who is bred to Boar C a Berkshire
this produces female ABC (25/25/50 yorkshire/GOS/Berkshire) who is bred to Boar A a Yorkshire
offspring is female ABC (62.5/12.5/25 Yorkshire/GOS/Berkshire) breed to Boar B a GOS

You and your friend would have to keep three boars of different breeds for this system. This scheme would give you healthy productive sows with hybrid vigor, for every gilt you decide to keep you would always breed her to a boar from the breed she has the least of. All the male offspring in this system would be sold, replacement boars would be bought. Gilts showing the traits you want would be kept. Select 2-5 traits you want in your pigs, make up a scoring system for the traits you want, score the potential keepers for each trait and add it up. Whichever pigs have the best scores should be kept. Don't pick more than 5 traits to select for as this will just turn into a mess to keep track of and no improvement will be made.

Here is a good website to find information on different breeds. http://www.ansi.okstate.edu/breeds/swine

If you decide to go with purebred pigs or creating your own landrace breed, you need to know about the effects of inbreeding. Inbreeding causes rare recessive traits to be expressed. These can cause severe health issues, if you do plan to inbreed, you have to cull very heavily to eliminate problems. Regarding line-breeding vs inbreeding, line-breeding is a term invented by lazy people who wanted to inbreed because they couldn't be bothered to go get unrelated animals. There is a way to calculate inbreeding, the formula is 1/2 to the power of X. This site has a pretty good explanation:

http://abri.une.edu.au/online/pages/inbreeding_coefficient_help.htm

Breeding a pig to it's parent results in a value of 0.25. If you end up with animals with numbers this high you have a serious problem. Inbreeding depression occurs when inbreeding values approach 0.10. Inbreeding depression is when the immune systems are compromised by a lack of genetic diversity.

I hope you find this helpful.

The problems with inbreeding are caused by people who fail to do hard selective breeding. Cull very hard. I figure that 95% of our gilts go to meat and 99.5% of our boars go to meat. Only about 5% of animals get a chance to test breed to produce possible contenders for the next generation. This is how evolution works. This is what Mother Nature does. It works.

First you need to know how to take care of pigs.

Then you need to know how to recognize good traits vs bad.

Then you must ruthlessly cull bad traits and select for good traits generation by generation.

Most of all, I would suggest you start with good genetics to begin with. Get breeders from someone who is already raising pigs the way you want to do it and ideally in your climate.

It is a long process. Rinse and repeat. Be dedicated to the long run.

-Walter

....." line-breeding is a term invented by lazy people who wanted to inbreed because they couldn't be bothered to go get unrelated animals."....

I disagree. Line breeding is often intentional. It's not because a breeder can't be bothered or is lazy, though I'm sure there are some who may be.

Line breeding is a form of inbreeding. The term denotes the mating of related animals who are not being bred to their parents or siblings. Close (or tight) line breeding often is interpreted as the same individual showing up on a three generation pedigree (but not involving parent or sibling matings). Loose line breeding implies that repeated individuals are further back than three generations. These definitions are generalities.

Line breeding is used to help fix traits. It is much slower than inbreeding, but considered safer by most breeders. Regardless of which strategy is used, ruthless culling is a must. It is the only way to achieve or retain your selected traits in your breeding stock.

I agree with Walter. Ideally, most of your pigs will go for meat. Only a chosen few will be used to produce the next generation.

Personally I've had the best success with line breeding and inbreeding when attempting to fix certain traits in my breeding stock. Multiple generations of outcrossing got me nowhere, other than lots of lackluster offspring and considerable variations within the litter. But with crossing breeds, I found the best consistency with the initial cross (F1). If you are intending to mix three breeds, it may become more mumbo-jumbo.

Line breeding is a powerful technique in genetic selection and herd improvement. I would recommend more real world experience.

Su, you and I are using different definitions of line-breeding. The definition of line-breeding I am using is where successive generations are bred back to their own parents. For example an individual, usually female, is bred to her sire. If female offspring occurs from this mating, she too would be bred back to the original sire. Some people do this on purpose hoping to recreate the original animal. The definition of line-breeding you are using is what I would call inbreeding, it would result in somewhat more genetic diversity than the definition of line-breeding I am accustomed to.

You mention using it to fix certain traits in your breeding stock. This definitely will work. My concern is that someone with no or limited experience might accidentally fix health problems into their breeding stock. So for a newbie such as Bella it would make a lot of sense to use crossbreeds for at least a few years, so there is less likelihood of genetic health problems being expressed.

Walter you have way more knowledge than me when it comes to pigs, I grew up around cattle, not pigs. I have been transferring what I know about cattle, and cat, genetics to pigs. With pigs you might get a little more leeway on inbreeding because you can cull harder. To cull 95% with cattle would shrink a herd pretty fast, this could be why beef cattle are often crosses, so heavy culling is not so critical. If I were to raise pigs I would follow be following about 95% of your advice.

Limited inbreeding done for a specific purpose can work, but if done improperly as I have seen way too much, it will ruin a herd.

Leora Laforge wrote:Walter you have way more knowledge than me when it comes to pigs, I grew up around cattle, not pigs. I have been transferring what I know about cattle, and cat, genetics to pigs. With pigs you might get a little more leeway on inbreeding because you can cull harder. To cull 95% with cattle would shrink a herd pretty fast, this could be why beef cattle are often crosses, so heavy culling is not so critical. If I were to raise pigs I would follow be following about 95% of your advice.

That's why I breed pigs instead of cattle or humans. Mice are good too.

Leora Laforge wrote:Limited inbreeding done for a specific purpose can work, but if done improperly as I have seen way too much, it will ruin a herd.

Just because someone somewhere does it wrong doesn't make it bad. Cars kill people. No, people die in car accidents. Different.

Just because someone somewhere does it wrong doesn't make it bad. Cars kill people. No, people die in car accidents. Different.

I like this analogy, now if people could get a learners licence, and practice under supervision, before taking a test that would allow them to get their full licence. Start by practicing with the equivalent of back roads where mistakes aren't so damaging, i.e. genetically diverse animals, or mice. After some practice they would move onto something a little more risky, i.e. livestock with a small gene pool. A system like this, which will never happen, would prevent a whole lot of mistakes that are making animals miserable and costing the people who own them money.

Leora Laforge wrote:I like this analogy, now if people could get a learners licence, and practice under supervision, before taking a test that would allow them to get their full licence.

Leora, you misunderstand. You don't need a license or training to drive a car. Only one to drive on the road.

The last thing we need is more licensing, testing and government regulation.

The beauty of breeding is we can eat mistakes. Evolution works. That which doesn't work, fails. Look at the long picture please.

You and I are on opposite ends of the spectrum. I'll not bother replying again.

Bring in 10% new blood ever generation.
Have 3 generation running at the same time.
Eat\Cull at least 80% of the animals.

Now as to what do you save for breeding. The ones with the color and marbling, that are the most successful (forage, good feed to weight ratio, not sickly, climate hardy, calm, etc)

so I can breed my sows piglets to the same boar(their father) is this alright in pigs I know its not recommended in cattle

Thanks so much for all your input, everyone! I agree that the best way to start is to have good quality pigs to begin with, and to keep things simple. I'll keep you updated on how things go! And Walter- huge thanks for all the work you've put into your site. I was like a kid in a candy store when I found all your articles.