Mule = horse mother + donkey father. A hybrid that exceeds both parents.
Advantages
Endurance: works in heat when a horse collapses. Drinks less. Eats less. Goes on trails where a horse refuses. Health: gets sick less than horses (hybrid vigor). Hooves harder — needs shoeing less. Intelligence: a mule won't do what it considers dangerous. A horse may panic and break a leg. A mule — never.
Disadvantages
Sterile (can't reproduce). Stubborn — but it's not stubbornness, it's caution. Mule refuses to go = danger ahead. Trust the mule.
With Amish
Some communities use mules instead of horses — cheaper to keep, live longer (30-40 years vs 25-30). For mountain communities (Kentucky, Tennessee) — irreplaceable on steep slopes.
Price
$1,500-5,000. Upkeep 30% less than a horse. Works until 35. Lifetime cost of ownership 2-3x lower than a horse.