Dairy cows will produce more butterfat on a ration in which whole (cracked) soybeans provide the protein supplement than on an ordinary ration of mixed grains which uses such a protein supplement as soybean oilmeal.
Cannon, C. Y.; Williams, N. Kenneth; and Espe, D. L.
"Cows Are Good Bean Market,"
Farm Science Reporter: Vol. 3
, Article 5.
Available at: http://lib.dr.iastate.edu/farmsciencereporter/vol3/iss1/5