- The fattening performance is very much influenced by the age of pigs and their compensatory growth; hence, pigs should be as old as possible (≥1 year) and adapted to grazing.
- Grass is necessary as a source of protein to compensate for the low protein levels in acorns.
- The food conversion rate is 10.5 kg of whole acorns of Q. i. rotundifolia to gain 1 kg, besides the contribution of grass; to establish the stocking rate, consider that an adult evergreen oak produces ≈11 kg of acorns/year).
- Iberian pigs peel acorns to avoid the high content of tannins in the shell. However, during peeling, approxi-mately 20% of the kernel can be wasted