What kind of Straw?

I am soon going to need straw for winter bedding and am just wondering what's best. Is there any that breaks down slower? Is warmer?

I prefer wheat straw.
It should be long and rather hard, almost like chopsticks. This will keep it's loft and warmth holding properties.

Barley straw breaks down quickly and has little pokey needle things in it
Oat straw can be of various qualities, some of it turns to powder the moment you use it, some just flattens, some holds it's form for a litte bit.
Flax straw makes the birds or dogs shiney, but it flattnes very quickly
Ditch grass is very poor for bedding as is orchard grass. It flattens out and forms a dense mat.

NOt all wheat straw is the same. I have had some that lasted in a dog house for a month, and some that lasted for a week. I found that for the chickens the what straw worked the best for nesting material.

I know baled flax straw can sit in the feilds for years. Not sure about its composting qualities... I'm using wheat straw as well, myne does compact a bit, but overall it does the job.

That's a great summary - thanks! The pigs prefer wheat straw too, but it is very difficult to find here. I may have to settle for barley straw.

I like a little of both. When I do my coop my nest boxes get Barely straw, it is softer and seems smaller peices so they like it better. I do have to fill the boxes once a week but I like cleaning them out weekly anyways. As the nest boxes get cleaned the barely straw mixes with the wheat straw on the floor and makes a nice area. I find the wheat straw does not absorb well so nice to have a bit of a mix in there in the winter especially so it can absorb any moisture that might come into the coop with the birds.

wheat straw breaks down good. So that should be a decent choice. I would not recomaned rye straw as it takes for ever to break down!