Milk producer breaking bottom off jug (3)
I believe the answer is:
'milk producer' is the definition.
(ewes are female sheep)
'breaking bottom off jug' is the wordplay.
'breaking bottom off' means to remove the last letter.
'jug' becomes 'ewer' (type of vessel).
'ewer' with its final letter taken off is 'EWE'.
(Other definitions for ewe that I've seen before include "Lamb supplier" , "Directions" , "Female ovine" , "Palindrome for a female sheep" , "Wool supplier" .)