[Elsiejay]

“No one knows how to farm without tractors.”

There does not exist a “reservoir” of horses, esp. those of the “draft” breeds; IATW, ditto in re tillage, seeding and harvesting machinery suitable for live horse power.
As a child/youth, I worked on a number of Minn./Wis. farms, powered exclusively by horses for routine field operations.

[Daffynition]

Those darn Amish again.

Mules are feeling left out.

[dware]

There does not exist a “reservoir” of horses

Sure there are. And I know where to find a whole bunch of them right close to me. There are a number of areas here in the west that still have wild horses running free. We have a pretty decent # of them (100+) right up the road from where I live, about 20 miles from me, in a local wilderness area.

There are other areas as well. The BLM thins the herds every couple of years. Left unchecked, the populations would actually grow pretty fast, as there is plenty of food for them where they roam. Allegedly, the wild horse population here where I am is descended from the local natives who let their horses loose after losing battles, being pushed out of their territory, etc.

[steve86]

There does not exist a “reservoir” of horses, esp. those of the “draft” breeds; IATW, ditto in re tillage, seeding and harvesting machinery suitable for live horse power.

True about lack of suitable horses and most people nowadays don't even know the vocabulary you're using like "tillage".