[Cob] cob mixing

[Jilly]

Cob... "traditionally coarse, therefore do not expand and contract extensively. Soils are usually found to contain well-distributed range of aggregates, from coarse gravel to sand and silts... "
"...mixed by their animals, horses, oxen, cows...." 

Is there a reason for mixing cob barefoot? If it was originally mixed by hoof, why injure a tender foot?

jilly