How was a supply of horses organised in the 20th century?

by theraceforspace

As everyone on the internet is happy to tell you these days, every army in Europe was still reliant on horses for, well everything that moved until the retaking of Europe and the introduction of the American industrial machine. How did European nations ensure the supply of millions of horses? Were there nationalised horse farms? Horse specifications?

Bronegan

Are there specific nations you are interested in? I ask because I've gone into how the British tackled their horse problem in the latter half of the 19th century and early 20th here.