Chooks can be funny about those Calf Manna pellets. Sometimes they wolf them, and sometimes not. Soaking the CM in with the grains softens up those pellets, and the stuff is partially absorbed into the swollen grains. The result is no waste.
When you start adding whole grains to a good 20% ration, you are LOWERING the protein level . Adding the Calf Manna brings it up to the 20% level again. Herb Holtz from Iowa, told me about whole grains improving size, and body mass, years ago. He raised 2 groups of birds from the same breedings. One was fed whole grains in addition to their Starter. The other got ground grains added to make the same protein level. He slaughtered both groups. Not only were the whole grain fed birds larger, but their digestive tracts and gizzards were much larger. Anyone who saw Herb's birds had no doubt he knew what he was talking about. I have followed his advice for 40 years.