Robb, there is not a simple answer to what appears to be a simple question.
Protein requirements change with periods of gestation and lactation. A dry cow in the fall does not have as high a protein requirement as a cow in the third trimester of gestation or that of a cow nursing a calf.
PPRM is so correct in that we have been brain-washed about protein for years (and from people who have made their living over-selling protein.)
If you have a 16% protein pellet and it is 10% moisture and you feed 2 pounds of it, you are actually getting only .288 lbs. of crude protein in the cow. That isn't enough to do much one way or the other. Good or bad. I think the protein requirement of a 1200 lb. cow, in the fall is about 1.7 lbs. of crude protein. After she calves it goes to 2 to 2.5 lbs. of crude protein. I saya this without looking it up, but if I am wrong, I am sure someone will correct me. I post it in order to show you the amount of protein you are providing with the pellets in relation to what a cow requires. (Of course, you are not just feeding them pellets, and I didn't go into that at this point. I am merely intending to show you the effect of the pellets.)