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September 21, 2007

First Mammoth Jackstock Newsletter - Part 1

This is the first Mammoth Jackstock Newsletter. This is a brief overview of some of the questions, comments and history a few of us have been discussing recently. If you have any articles that you'd like to submit for the newsletter, please forward the article to me, Tanya, at or Nelda at If you have a certain product that you'd like tested on jackstock, email your suggestions to Marna at

Hello Everyone,
This is the first monthly Mammoth Jackstock newsletter, and hopefully, there will be many more. In the computer era, we have so many more ways to keep in touch with other people in our community than in the past, yet we don’t have a single newsletter, magazine or anything else to keep people who are interested in Mammoth Jackstock connected. There are several publications out there today, most of them have a bit about donkeys of every size, and a bit about mules. They are all very good publications (which I have subscribed to all of them, and still subscribe to The Brayer from the ADMS), but what I’d like to see is one that is just for Mammoth Jackstock.
So, to start the newsletter, I’d like to throw out there some of the questions and issues we have been discussing lately on the Yahoo Mammoth Donkeys list. One, are American Mammoth Jackstock a breed?? In the U.S. they are mostly just a big donkey, registered by height. Does this constitute an actual breed?
Many people feel that there are two distinct “types” of Jackstock. The old preservationist type, which are drafty, big boned animals that were used in the past to breed to draft mares to make wonderful draft mules, for working the fields. And today’s more refined, “saddle” type, which many people feel are a more athletic, performance animal. Can there be two types in a breed? I feel that both types can fit into one breed category, although some others feel differently.
One other issue is what are the breed “standards” or characteristics, that would make them a breed that you could distinguish from other breeds of big donkeys around the world? Regrettably, many early Jackstock breeders didn’t keep good records of lineage, or records were lost over the years. This gives us a little bit of information and a lot of guessing. One registry (The American Mammoth Jackstock Registry) has standards to be met other than a height requirement. The AMJR requires that jacks be at least 58”s and jennets and geldings must be 56”s. Another requirement is that the donkey is at least 61”s around the heart girth. The last standard is that the donkey measures at least 8”s at the cannon bone (measured around the cannon bone midway between the knee and the fetlock) for jacks, and 7 ½”s for jennets and geldings. This registry also states that a burro cross is not characteristic of this breed. An animal bearing the burro cross is not eligible for acceptance into the registry. In the past, there were also required measurements of the ear span, and the donkey had to be black with white points. Eventually, the registry allowed other colors to be accepted.
The ADMS (American Donkey and Mule Society) registers animals in regards to height only. A jennet must be 54”s in height to be registered with the ADMS as mammoth, and a jack or gelding must be 56”s in height to be registered. An important side not, Leah Patton from the ADMS states that big donkey registrations are way, way down this year and have been declining for several years now.
The need for registering animals is important. One, we need to have documented bloodlines. Two, we need to make sure animals that are inadequate as breeding animals are not rebred. Most breeders know if an animal shouldn’t be bred, and will sell the animal as a saddle animal, or other using animal. Only a handful of irresponsible breeders will breed an animal no matter what the conformation or personality. Only the best donkeys should be bred, the ones with the best conformation and the best personality. Most of the breeders I have contact with only want to improve the breed and are very responsible.
To actually establish American Mammoth Jackstock as a breed, I have been told that a studbook would need to be established with parent verification. DNA testing would have to be incorporated eventually. I know of a few DNA labs that can do testing on donkeys. See below for a few of them.
Luckily, Pet DNA Services of Arizona has also been in contact with Leah Patton from the ADMS and is going to begin developing tests for coat color genes in donkeys. We definitely need more research in that area.
Apparently, donkeys (standard sized) made their first appearance in the new world in 1495, brought by Christopher Columbus. Four males and two females. These donkeys started the foundation of the donkeys who would carry the Conquistadors as they explored the Americas. President George Washington, with some gifts and purchases, imported big jacks (Catalonion, Andulusian, and Poitou, to name a few) from Europe in the late 1700’s and early 1800’s. Interest quickly grew, and there were an estimated five million mammoth donkeys in America in 1920. In the 1950’s, mammoth jackstock started to decline. There was a slight resurgence in numbers in the 1980’s.
Mammoth donkeys were primarily used in the production of draft mules, to work the fields, and are still used in mule production today. But, they are as likely to be pleasure animals, used the same way as horses, for trail riding, showing, and even dressage. These versatile animals are finding their own niche in the equine world.
I hope you enjoyed reading this short article. We have lots of articles lined up for the future, covering DNA testing, jack keeping, health issues, etc. If there is anything that someone would like an article on, please feel free to email me, and I will do my best to get an appropriate article into the next newsletter. Also, if anyone would like to submit an article, you can contact me at or . We would like articles on your donkey club, shows, and rescues too.

If you are interested in DNA testing, here are a few links help out:
Pet DNA Services of Az, Chandler, AZ 85246
tel: 602-380-8552
The services offered by PDSAz include DNA tests for horses (coat color genes, white spotting, HYPP, HERDA), and DNA sexing of birds. We are also conducting genetic research of coat color genes in donkeys, and of the seal brown color in horses.
Michal Prochazka, MD

UCDavis-Veterinary Genetics Laboratory

University of Kentucky

Posted by Tanya Tourjee at September 21, 2007 01:17 PM