Well It Is Good And Bad. Straw Or Hay Can Acctually Begin To mold Which Will Begin To Produce Bacterium. These Bacterium Will Cause Botculism Which WILL Kill Chicks And Weak Birds. This Will Cause A Limp Neck And Stiff Joints. Straw However Can Be Good For Hens To Nest On. But Not For Flooring Us Pine Shavings But Don't Use Cedar.
Hope This Helps.
-Ben Rowe

pine shavings are ok if they get rained on?? willl they cause mold bacterium too?

Just to clarify, beeliz is asking if straw would be good outside. I might understand it not being best for indoor flooring, but wouldn't it be ok for outside in the pen area?

I use straw and one of the problems I find is that it actually gets stuck in the ground. I am thinking of using a combo of straw and pine shavings.

If you are trying to avoid a muddy mess, for whatever reason, then you might do better to totally clear the area, lay down gravel as a drainage help, and cover it with finer gravel and then sand. The sand can be raked and cleaned more easily then you can pick straw out of mud, especially mixed with manure. If that - which is the "best" thing to do as far as longevity goes - is impossible, then I would go with a fairly thick layer of shavings, rather than straw. Of course, if you already HAVE the straw, and the others cost money you don't want to spend, then go with the straw. I would spread it thickly enough that it won't immediately be trodden into a muddy mess, but not knowing the site, nor the animals, I can't say how thick that is - experiment and see.