Value of High-Silage Rations for Fattening Beef Cattle

During each of 2 years a feeding trial and a series of digestion trials were conducted to study the value of high-silage rations for fattening yearling beef steers. The silages used consisted of corn silage made from a high-grain yielding corn variety, and high- and low- moisture alfalfa-orchardgrass silages. The dry matter content of the corn silage was 30.9% and of the high- and low-moisture grass silages was 22.9 and 43.3%, respectively. The determined TDN, dry matter basis was 70.6% for the corn silage and approximately 60% for the grass silages. When fed alone, grass silages produced poor feedlot performance, especially for the cattle fed the high-moisture silage. Performance was improved markedly when these silages were supplemented with 8 lb. ear corn. Rate of gain for the steers fed corn silage as 80 or 100% of forage dry matter intake, plus limited amounts of cottonseed meal, was lower than for those fed a conventional high-grain fattening ration, but differences usually were not significant. Feed efficiency, expressed as pounds of dry matter or TDN per pound of gain, was highest for the lots fed corn silage as the only forage, or as 80% of the forage dry matter plus limited protein supplement. Cattle fed the high corn silage rations produced carcasses grading high good to low choice; these grades were not significantly different from those of the carcasses from cattle fed a conventional high-grain fattening ration.