The effects of additions of urea and sulfate sulfur to corn silage at varying stages of maturity used for the production of market beef heifers in Tennessee

One hundred and twenty medium grade heifers were involved in a three-year study of the production of market beef heifers fed urea, limestone and/or sulfur treated corn silage cut at various stages of maturity. The heifers were full fed silage for approximately 116 days and then full fed grain for approximately 74 days or until they reached a condition grade of low good to average good. Each year 40 heifers were uniformly lotted into eight lots on the basis of weight and type and condition grades. The heifers were fed four treatments with two lots per treatment and 28 day weights were recorded throughout the trial. The heifers were graded and subjec-tively evaluated at the beginning and end of both the silage and con-centrate phases. At the completion of the concentrate phase the heifers were sold to a packing plant and carcass data were obtained. In 1968 and 1969 there was no significant difference (P\u3c.05) in ADG of the heifers when fed urea-limestone treated com silage harvested at three stages of maturity. The results also showed no significant difference (P\u3c.05) in ADG, feed consumption and total ADM per pound of gain when sodium sulfate was added to the urea-limestone treated corn silage to maintain a 12:1 nitrogen to sulfur ratio. During the three-year study (1968-70) there were no significant carryover effects (P\u3c.05) from the silage phase to the concentrate phase due to the addition of urea, limestone and sulfur to green chop at ensiling time. In 1970 one of the four treatments of silage contained 20 pounds of urea, 10 pounds of limestone and 3 pounds of sodium sulfate per ton of green chop. The additional 3 pounds of sulfur was added to maintain a nitrogen to sulfur ratio of approximately 12:1, None of the results showed any significant difference (P\u3c.05) due to the additional urea and/or sulfur. There were no significant differences in carcass data results due to the treatment effects of the silage