Roll contains duck and chicken (7)
I believe the answer is:
rooster
'chicken' is the definition.
(I know that rooster is a type of chicken)
'roll contains duck' is the wordplay.
'roll' becomes 'roster' (roll can mean a list or roster).
'contains' is an insertion indicator.
'duck' becomes 'o' (resembles zero - 'duck' in cricket).
'roster' placed around 'o' is 'ROOSTER'.
'and' is the link.
(Other definitions for rooster that I've seen before include "Cockerel (mainly US)" , "Chanticleer" , "American cock" , "Crowing bird" , "Farmyard cock" .)