Minecraft will not spawn any pigs in this area. It fits the required dimensions on the Minecraft Wiki.
"A monster spawner is only active when a player is within 16 blocks of it. While the block is active, it will spawn mobs within an 8x3x8 block area (8x8 wide and 3 high), centered on the corner of the spawner block with the lower x and z coordinates. Mobs can spawn anywhere in this range that is suitable, even if the immediate vicinity of the spawner block itself is not suitable."
Our area fits these dimensions exactly, why wont pigs spawn? Picture of area: