Horses, mules, donkeys. Rainfed or irrigated pastures. Industrial livestock systems. Animals typically kept in large numbers, in barns or outdoor pens, with all feed brought to them. Feed may be grown on adjacent land or brought from a distance.
Operations are usually highly mechanized.
Vitamins and minerals. Mixed crop-livestock systems. Both crops and livestock produced on the same farm. Animal feed provided by crops, crop residues, as well as grazing, and animal manures returned to the cropland. Animals are often used for traction and transport on the farm.