not enough animals

there are not enough animals on world

What I expected to happen was...:
i am running server with xmx1024mb and xms1024mb nogui. I expect lots of animals spawning.

What actually happened was...:
animals are spawning only at distance at new chunks genereated.

Steps to Reproduce:
1. make server with spawnmonsters false and then run minecraft
2.login to server
3. wander around