Farm labourer holding hearts in game (8)
I believe the answer is:
pheasant
'game' is the definition.
(I know that pheasant is a type of phasianid)
'farm labourer holding hearts' is the wordplay.
'farm labourer' becomes 'peasant' (someone working on a farm).
'holding' is an insertion indicator.
'hearts' becomes 'h' (abbreviation used in card games e.g. bridge).
'peasant' enclosing 'h' is 'PHEASANT'.
'in' is the link.
(Other definitions for pheasant that I've seen before include "Ant heaps (anag.)" , "Game-bird" , "Wildfowl" , "Cock" , "Large game bird" .)