Basically laying mash or crumbles and laying pellets are the same feed just processed into different forms. Mash or crumbles is designed to be dispensed in large operations with screw type conveyors where pellets are designed for the small operation that feed in hanging feeders and the like. The mill where my feed comes from has mixing machines that make all their feed into pellets but they crush them into crumbles for their large scale customers who use automated feeding systems. Very few mills actually make mash to be served wet like was mentioned earlier, the folks that like to feed wet feed generally ferment laying crumbles themselves into mash feed.