JED 1.6.0+ - Disable animal spawning in the Overworld

{
    "dimensions":
    [
        {
            "dim": 0,
            "override": true,
            "dimensiontype": {
                "id": 0,
                "name": "Overworld",
                "suffix": "",
                "keeploaded": true,
                "worldprovider": "WorldProviderSurfaceJED"
            },
            "jed": {
                "CanSpawnHostiles": true,
                "CanSpawnPeacefulMobs": false
            }
        }
    ]
}