At least one US farmer has switched from gasoline engines to mules:
MCMINNVILLE, Tenn. --
High gas prices have driven a Warren County farmer and his sons to hitch a tractor rake to a pair of mules to gather hay from their fields.
"This fuel's so high, you can't afford it," he said. "We can feed these mules cheaper than we can buy fuel. That's the truth."
Brother Robert Raymond added, "It's the way of the future."