The Meaning of Life, the Universe, and Everything.
Rotten flesh is one of those things that just lies around, taking up space, so why not take advantage of it? As you may (hopefully) be aware, this isn't an original idea, but it is the first mod that does so in 1.8. On top of that, it's an MCP mod, meaning you can install it without Forge or that stuff, meaning you can put it alongside your Optifine and Tickspeed mods. The installation is simple - go to your minecraft.jar, drop in the file below, and delete META-INF. It's compatible with most other MCP mods (though not Forge, if anyone wants one I can make one for Forge 1.8), so it shouldn't be too much of an issue, but if you need help I'm always here.