In Agrarian Skies, for whatever reason, while the tooltips for Brain Jerky (from Witching Gadgets) say it should restore around half a shank or so, it actually restores its default value.
I'm not sure if this is for balance reasons (making you have to wait longer between eating aspect-point-giving, warp-free brain jerkies) or not.

• If you're talking about Agrarian Skies for Minecraft 1.6.4, then that version of TSoL is no longer supported
• If you're talking about Agrarian Skies 2 for Minecraft 1.7.10, then that probably means Witching Gadgets needs to make sure that its food is compatible with AppleCore.