Bags in stock, those remaining for one with a blocked nose? (6)
I believe the answer is:
udders
'bags in stock' is the definition.
(stock can mean farm animals)
I can't explain the rest of the clue.
(Other definitions for udders that I've seen before include "Milk producers" , "These full of milk" , "de rest" , "Cows' teats" , "Containers for milk, naturally!" .)