Found a sabertooth on the beach near my base so I knocked it out, and I put raw prime meat in its inventory. It stopped eating entirely, even the regular raw meat in its inventory went untouched. Its hunger dropped to 300 below max and it did nothing. I tried to force it to eat it and it recovered 50 food but did nothing to the taming bar.
I imagine this has something to do with the brand new kibble system and the nerf to prime meat on taming speed.