My experience has been with sawdust is it is far more absorbent and easier to deal with than straw. Unfortunately, if you're raising cornish x (meat chickens), they tend to eat the shavings/sawdust and it fills up their crop. It does not digest.
All of my chicks have been raised on newspaper over top the shavings/sawdust for about a week, maybe less. The newspaper is in layers so it can be removed daily or as needed with as little disturbance to the chicks as possible and a fresh layer of newspaper will remain. Once the chicks are old enough they KNOW what they are supposed to eat, there usually is little problem with them eating the bedding.
I used sawdust from the local sawmill for years and it has spoiled me for anything else. Hope this is helpful to some one.