The amount of time you must have spent considering Pete’s dong, or the potential lack thereof, is mildly worrying
Assuming this is a legit question/concern, the mechanical logic likely ran - “Oh, we need to give the Chef a way to get milk. We have Pete already. Goats can make milk. Let’s make Pete milkable.”
That said, the first thing I do as a Chef is kill Pete, because he’s a raging cunt who attacks me 4noraison.
Pete’s mystery liquid is not milk nor is it “the unmentionable fluid” it is in fact a class a drug that acts as a sedative and Pete is not a goat he is a changeling who had a genetic malfunction and is now permanently disguised as a goat which is why he attacks you