Urea use as a substitute for plant protein supplements is increasing on Iowa dairy farms. With judicious use of urea, most dairymen can save $5 to $25 in yearly feed costs for each cow in their herd.
Van Horn, H. H. and Foreman, C. F.
"A Situation Report: Urea for Dairy Cows,"
Iowa Farm Science: Vol. 21
, Article 2.
Available at: https://lib.dr.iastate.edu/farmscience/vol21/iss4/2