Modified Urea Supplements with Corn Silage for Wintering Ewe Lambs

Two wintering studies with western crossbred ewe lambs were made using urea supplements with corn silage. The daily supplements fed contained amounts of nitrogen and energy equal to that in 0.25 lb. of 44 percent soybean oil meal. Initially in the 1951–52 lot feeding test urea replaced two-thirds of the nitrogen of soybean oil meal. Cerelose was added for energy. Elemental sulfur was included in two supplements at the rate of 5 gm. daily per lamb. Average daily gains per lamb in pounds for 140 days were: soybean 0.137; urea-cerelose 0.115; urea-cerelose-sulfur 0.138; twice urea plus sulfur 0.141. Gains were not significantly different. Wool yields for the urea-cerelose-sulfur group while greater than for the urea-cerelose group were not significantly different. Average wool yields for soybean oil meal, urea-cerelose-sulfur, and for twice urea groups were statistically greater than for the urea-cerelose treatment. In 1952–53 urea supplements were formulated without soybean oil meal. One source of energy used was equal parts cerelose and starch and another was yellow corn. This second study included a 37-day lot feeding period (phase 1) of corn silage with a urea-cerelose-starch supplement followed by a 56-day individual feeding period (phase 2) of regular corn silage and modified urea supplements. SO2 treated corn silage was fed the last 28 days (phase 3). During phase 2 the soybean oil meal supplemented lambs made highly significantly greater gains than lambs receiving modified urea rations. The addition of 0.2 percent elemental sulfur to modified urea supplements increased gains significantly, and the use of ground corn as an energy source in place of cerelose and starch affected a highly significant improvement in gains. Nitrogen balances improved through the addition of sulfur and from the use of corn but differences were not significant. Wool growth favored the sulfur supplemented rations, though not significantly. Upon feeding of sulfur dioxide preserved silage during the last 28 days statistical differences in lamb gains of phase 2 were erased.