Urea as an Extender of Protein When Fed to Lambs

Cottonseed meal, crystalline urea, DuPont's “Two-Sixty-Two” feed compound and pelleted concentrate feeds containing approximately 4, 8 and 12 percent of urea were fed as sources of supplemental nitrogen for lambs during digestion and nitrogen balance trials. The addition of urea alone and as "TwO-Sixty-Two" to a basal ration of low-protein prairie hay increased the apparent digestibility of hay nutrients and changed nitrogen balances from slightly negative values to slightly positive values. Pelleted feeds with 25 percent of their total nitrogen supplied by 4 percent of urea permitted about the same storage of nitrogen as cottonseed meal. Nitrogen storage decreased as the proportion of total nitrogen supplied by urea was increased in the pellets to 50 and 75 percent.