I've always heard laying mash and that's what I use. Seeing them side by side in open bins in the feed store, thae laying mash is a bit smaller and should break down faster, besides having a bit of Ca added for the eggshells. But really, both are just cracked/slightly ground corn with very little difference.
The only thing everyone agreed on was not to bury it or, it would sour. I'll mist it just enough to put a sheen on it and it will be gone in 2-3 days. This is just sprinkling a small amount on the surface of the bin.
A 50# bag lasts forever, even in a large operation, but only costs $10-$12. Smaller amounts are $1/lb, so it's worth getting something to store it in and many places don't sell under 50lb bags.
IDK about the breeding part, down here the mash is used to fatten up fishing worms and it does do that. Good stuff!
Wet