Present president, bovine (8)
I believe the answer is:
hereford
'bovine' is the definition.
(I know that Hereford is a type of bovine)
'present president' is the wordplay.
'present' becomes 'here' (both can mean in attendance).
'president' becomes 'ford' (Gerald Ford).
'here'+'ford'='HEREFORD'
(Other definitions for hereford that I've seen before include "cross breed of cattle" , "cow!)" , "English cathedral city" , "City on the River Wye - cattle breed" , "Place" .)