Question of the day: Can you guess which are “Pure Meishan Pigs” or “Crossed with Meishan?”
Take your best guess, the answers are on page 2 of this post.
Why Not Just DNA Test?
Let me start off this post with one very definitive statement. There is no DNA test available to determine the ‘Purity” of Meishan pigs. I have talked to leading swine geneticists and the folks at UC Davis who do livestock DNA testing. The only DNA testing readily available is quite simply a paternity test for pigs. That is if both parents’ DNA samples are on file then UC Davis can sample the DNA of purported offspring and say yes this is the direct offspring or no it isn’t. But that is the limit of their capability. Current swine DNA testing can’t tell you if two pigs are brother and sister. These tests can’t tell you if a pig is “pure”. They can’t tell you anything if even one parent or one generation is omitted.
Chain of custody or eye test for Meishan Pig purity?
So in the effort to recover as much of the original pure genetics of the 1989 importation of Meishans how could we here at the American Meishan Breeders Association® determine purity. The A.M.B.A.® considered two different approaches. One was “chain of custody.” If the A.M.B.A.® could with confidence track a transactional record back to one of the research herds the first hurdle in the registration process would be complete. Then at least a two-generation pedigree would have to be submitted (for COI analysis). Finally, a review of the specific breeding practices (IE identification of subject pigs and isolation of males and females) of each individual submitter would be done. It represented the most reliable process for the identification of pure genetics we could develop.
No More “Pure on Appearance” in the A.M.B.A.
The other method, initially considered, was a “Pure on Appearance” grade status for females only. This program was actually announced. Then put on hold. However, as of October 2018, the consideration of a “Pure on Appearance” classification was scrapped completely by the A.M.B.A.® board. The reasons were twofold.
No definite visual markers for Meishan Pig purity
First, as submissions for consideration came in many folks were quite honest about the fact that the pictures they were providing were of known crosses. That is while the parent might be unknown the offspring were definitely crossed. One of the most striking things about the known crosses submitted was how “pure” they appeared to be. Meishans are estimated to have at least 2000 years of genetic separation from domestic breeds. Their appearance (phenotype) can be very dominant even at 50% pure or less. Because of this, we started an in-depth research project trying to seek out known crosses with known levels of Meishan Influence. This was difficult until we found a family-owned farrow to wean operation in Indiana who was gracious enough to help us (credits on the answer page).
Second, in other cases, people were submitting as “fact” information that was in fact false (see “Caveat Emptor” on the answer page). That is, pictures of parent pigs were not accurate. Sources of submitted pigs were not accurate. I suppose it is a compliment to the value that people place on registration but it created a very dangerous situation if the goal is to prevent genetic contamination of the registry.
We are often asked why are there so many Meishan-looking pigs that are crosses. The answer lies in the temperament of the Meishan boars.
Meishan crossed boars as “Heat Check Boars”
For decades Meishan cross boars have been prized in commercial applications that artificially inseminate their sows (AI). The industry term is “teaser” or “heat check” boars. Meishan boars have a high libido but gentle nature. Many different commercial breed sows have “quiet” heats. Some only cycle when exposed to a boar. These Meishan cross boars can detect or cause those heats. By their behavior, they can tell sow barn operators when to AI individual sows. Meishan boar semen has been available from several sources in the commercial hog industry for years. Some of this semen came from Iowa State, Some came from unknown sources. I have been told the British importation of Meishan pigs in 1987 was a possible source. Many of the commercial genetics companies are quite secretive about their Meishan semen sources and whether they have been maintained pure.
Lots of extra Meishan crosses that look “Pure”
In any case, typically these operations would breed a sow with Meishan semen and retain a boar or two. If gilts were retained they were bred back from the same semen source to “grade up” the level of Meishan in their “heat check” boars. However, this practice creates an excess of piglets. Meishan do not transfer well, based on growth rate carcass yield and lean yield, to the pork products sought by a typical commercial operation.
So now you have a supply of pigs that are:
- Excess with little value to the breeder
- Look like pure Meishan but are not
- Not documented or DNA testable
What happens to the extra “Pure Looking” Meishan Piglets?
So what becomes of these excess crosses? I believe they become pets, rescues, items at exotic animal auctions and join the population of “pure looking” but undocumented pigs. Are there pure Meishans outside of those in the registry database? I would say most assuredly yes. We have found them. But in those cases, the breeders were unwilling or unable to submit the full scope of documentation we require. And that is fine. The American Meishan Breeders Association was not formed simply to determine purity. It was formed to provide an on-line accurate pedigree database so that the Meishan breed’s unique genetics can be cataloged and managed for generations to come. And today that database exists. Our members continue to report litter sizes and prolificacy that confirms we do have a genetically healthy breeding herd. The challenge is to keep it that way.
How many did you get right? Which were the Pure Meishan Pigs?
So how do you think you did on the quiz? It’s a fun exercise. You can get them all right, all wrong, or some number in between without consequence to the Meishan breed. But the A.M.B.A. doesn’t have that luxury.