That's more than half the cost (or may be, considering that there are two wildly different figures for the efficiency of tons of turkey parts per barrel of oil given in the article).
Lots of other sources: Landfills (old and new), agricultural waste (silage, manure, etc.), forest waste (limbs, foliage), anything that goes to a rendering plant, and most importantly human waste.
Wastewater treatment plants would become energy producers.
I find it odd that no one has mentioned biodiesel yet.