Top milk producer (6)

I believe the answer is:

jersey

I believe this clue is a double definition.

'top' is the first definition.
(item of clothing)

'milk producer' is the second definition.
(Jersey is a type of cow)

(Other definitions for jersey that I've seen before include "Pullover; an island" , "Woolly" , "Something one may put on" , "Top - cow" , "Clothing" .)

I've seen this clue in The Telegraph and The Sun.

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