Bovine expert a good many finally dismissed (7)
'bovine' is the definition.
'expert a good many finally dismissed' is the wordplay.
'expert' becomes 'buff' (I've seen this before).
'good many' becomes 'lot' (a good many can mean a lot).
'finally dismissed' means to remove the last letter.
'lot' with its final letter taken away is 'lo'.
(Other definitions for buffalo that I've seen before include "A hairy", "Wild animals", "American bison or related beast", "NY port; --- Bill (Cody)", "Large wild ox".)