These heavy animals are called draft horses, and were traditionally used for agricultural work before the advent of mechanized farming.
. . .
The Russian Draft (Russian Ardennes, Russian Heavy Draft) is not as heavy as some other draft breeds. Compact and muscular, these horses were originally bred for farm work.
. . .
Before the advent of mechanized farming, the heavy Dutch Draft was used primarily for agricultural work in the Netherlands.
. . .
In years past, the Breton was used by the military and for agricultural work. Today, they are still versatile horses that are used for many things, but they are also bred for meat.
. . .
The ancient Ardennes is descended from heavy warhorses used in Ancient Rome. These strong horses have been used for hundreds of years for heavy agricultural work, and they served as artillery horses during the French Revolution.
. . .