Such animal centers are quite popular in Europe, usually they are dedicated to only one species. Animals have a larger territory than at the zoo and this is the main difference.
We planned to go to the forest with a tour, where you can see elks in the wild, without nets. But were late about 30 minutes and had to visit only feeding. Find on the official website schedule of tours and feeding.
Tickets are quite expensive, as of 2018 they cost 180 NOK (18 EUR).
It i possible to eat nearby in the Landeskogen Peace Center. The cafe is something like a canteen, prices are moderate. Here is the place in Google Street View. The purpose of this museum is not clear, probably it was done to make people better.
Getting there: parking N 58 42.562 E 7 50.094. You can take bus 170 from Kristiansand (schedule), your stop is Årdal kyrkje.