Which preposition to use with milker

in Occurrences 2%

" "Those two beautiful sonnets that you transmuted into the cow that was accounted the worst milker in the township.

from Occurrences 1%

With the praise comes some little censure; and I am charged by more than one friendly critic with stupidity for not ordering the legs of our first cow to be strapped, which would, they consider, have prevented both milk and milker from being knocked over.

Which preposition to use with  milker