Hi all. I am new to unity 3d. I have a problem i have very basic scene and still my FPS is very low( less than 30 ). Please help me.

The easiest way is to read through the docs. Good Luck.

http://wiki.unity3d.com/index.php?title=General_Performance_Tips

So you modelled your assets in Maya? Click on your cow mesh in the project window (you might need to click the little arrow to expand the asset to get to the mesh). Look in the inspector pane. How many verts/tris does it have?

Depending on your target platform, you should generally look for there to be no more than around 100,000 vertices drawn to the screen.

20121-verts_tris.jpg