Cow (4)
'cow' is the definition.
(I have seen 'Young cow' mean 'calf' so perhaps 'cow' could also mean 'calf')
This is all the clue.
(Other definitions for calf that I've seen before include "Young animal associated with soft leather" , "Young of domestic cattle" , "Young cow/bull" , "Baby elephant or whale" , "A little lower" .)
(Other definitions for subdue that I've seen before include "'Quieten, bring under control (6)'" , "Overcome or inhibit" , "Overcome, force to yield" , "Bring under control, tame" , "Moderate" .)