A pack animal is a beast of burden used by humans as means of transporting materials by attaching them so their weigh bears on the animal's back; the term may be applied to either an individual animal or a species so employed.
The term is not routinely applied to humans carrying loads on their backs except to make a pejorative point about the injustice of so employing them, or about the privation that usually occasions accepting such work without explcit coercion. (The 1978Rolling Stones song Beast of Burden refers to a sense of abuse, accepted within a romantic relationship.) Nevertheless, from a physical point of view, certainly many considerations apply equally to human and other pack animals, without considering the range of social conditions ranging through slaves, abused women and children, Himalayan and African natives employed as expeditionporters, vacationing students whose duties as staff of mountaineering huts include packing stunningly heavy loads of supplies up steep slopes, and purely recreational hikers and backpackers including both short-trip ones, and long-trip backpackers who court injury and emaciation in carrying their heavy loads.
Another unconventional form of draft animal may be the dogs who are brought along on hikes carrying their own supply of drinking water and snacks on their backs, whether to provide them more exercise, or in pursuit of a hikers' ethic of "everyone carries their own gear".
A packanimal is a beast of burden used by humans as means of transporting materials by attaching them so their weigh bears on the animal's back; the term may be applied to either an individual animal or a species so employed.
Another unconventional form of draft animal may be the dogs who are brought along on hikes carrying their own supply of drinking water and snacks on their backs, whether to provide them more exercise, or in pursuit of a hikers' ethic of "everyone carries their own gear".
A working animal is a semi-domesticated animal that is kept by humans and often trained to perform various tasks, regardless whether they are also used for consumption of meat and milk or for other products (such as leather).
The history of working animals is as old as agriculture, and possibly longer, some speculate, and has encompassed most aspects of human civilization down to the present day with millions of animals working in symbiotic relationships with their owners around the world, particularly in poorer countries and in agricultural industries.
As the practice of using working animals spans millennia it has accrued much folk lore and forms an important connection between religion and agriculture, and is a specific focus of research in agricultural science.