Mammoth Donkey

The breed that resulted was built to sire mules out of draft mares, and for a century it did exactly that across the American South and Midwest, until tractors ended the work.

The registry history runs through three names: two registries formed in 1888 and 1908 merged in 1923 as the Standard Jack and Jennet Registry, which continues as the American Mammoth Jackstock Registry. The American Donkey and Mule Society also keeps a mammoth book, defined by size.

The Livestock Conservancy puts adult weight at 900 to 1,200 lb. The breed registry's minimums are 14.2 hands for a jack and 14 hands for a jennet or gelding, with 61 inches of heart girth; the size-class definition alone is lower, anything over 54 or 56 inches depending on sex. The ears run to 33 inches from head to tip.

Black was traditionally the only acceptable color and sorrel is now common. The breed registry prefers solid colors and roans and excludes white and spotted animals.

They are powerful, calm, and unusually gentle for their size; docile is The Livestock Conservancy's word.

The exception is the intact jack, which the Conservancy says should not go to owners without experience of intact equines, or to anyone not intending to breed. A gelding gives you the scale without the management.

Siring mules out of draft mares is the founding job. The Conservancy lists the modern uses as mule production using jacks, driving, riding and livestock guarding.

The trade is that the purpose largely disappeared. There is no commercial mule economy left to employ them, so the modern mammoth is a breeding animal, a saddle and harness animal, or a very large guardian.

Keeping one means keeping a very large equine that eats accordingly and founders on good grass like any donkey: feed at scale, but grazing managed rather than maximised.

Fencing, shelter and handling gear sized for an animal of 14 hands and up.

Numbers fell sharply after mechanisation, and the American Mammoth Jackstock, the registered conservation population, sits on the Conservation Priority List as Critical.

The registered stud books reach back to 1888. The unregistered big-donkey population, however large, is not what the Conservancy counts.

Mammoth without papers is a height claim. The size class starts above 54 inches for a jennet and 56 for a jack or gelding, and the American Donkey and Mule Society will register a donkey that measures in. The American Mammoth Jackstock herd book asks for more: the breed standard's minimums, and no burro crosses. Ask which registry, and ask for the certificate.

If the conservation side matters to you, buy from the registered population; this catalog's American Mammoth Jackstock entry is the same animal with the breed's full story.

Recent sale prices on HoofnHorn, where there are any, are further down this page.