The liver is roe deer. Soaking in milk, any game, will reduce its gamey flavour, and also add to the taste in some ways.

As for the language, he might be using a dialect??? Maybe one of our German members could comment? My German is extremely limited, my ancestors having left in 1838! So WHEN I have trouble I claim it is the language from the 1830's ... ha ha, my excuse anyway. The older locals here who still speak the "local dialect" known as "Barossa Deutsch" which can be very different from Hoch Deutsch (High German), at least what I was taught at school versus the local lingo.

Eating a deer liver from a freshly taken deer is a great hunting tradition.