Over-eating disease has kept a lot of Iowa farmers from self feeding their lambs. Enterotoxemia is the technical name for it. We don't know much about it; but we know some lambs die from it when they are self-fed on corn.
Culbertson, C. C.
"Full-Feed for Lambs,"
Iowa Farm Science: Vol. 3
, Article 3.
Available at: https://lib.dr.iastate.edu/farmscience/vol3/iss2/3