Utilization of Oak Sawdust as a Roughage Substitute in Beef Cattle Finishing Rations

Summary

Two trials were conducted to evaluate oak sawdust as a roughage substitute in beef cattle finishing rations. In both trials Hereford steers were fed rations containing the same basal ingredients but varying in the source and level of roughage. In trial 1, performance and carcass characteristics of steers fed 5 and 15% fine and coarse sawdust were compared to those of steers fed 5% ground timothy hay. In trial 2, comparison was made between steers fed rations containing sawdust and steers fed two control rations containing either 3% oyster shell or 15% ground timothy hay. Sawdust was included in rations at 5 and 15% levels, with three particle sizes (fine, medium and coarse) used at each level. Rumen fluid samples were taken from fistulated steers used in trial 2. In addition, two digestibility trials with sheep were conducted to determine energy digestibility of the rations used in the two finishing trials.

Feedlot performance data of both trials indicate that sawdust can be successfully used at levels up to 15 of the ration. Results were in favor of the coarser sawdust particles. Carcass characteristics of steers fed rations containing sawdust were essentially not different from those fed rations containing either ground timothy hay or oyster shell. Rumen pH, total VFA and lactic acid concentrations which resulted from feeding the rations containing sawdust were similar, except those resulting from feeding the ration containing 5% medium sawdust. The incidence of liver abscesses tended to decrease with increases in both sawdust level and particle size. Reduction in liver abscesses was also observed when the hay level in the ration was increased from 5 to 15%. Liver abscesses did not significantly affect either performance or carcass characteristics. Rumens of steers fed the rations containing sawdust were parakeratotic. However, improvement in rumen condition was observed when sawdust was included in rations at 15% level, and when coarser sawdust particles were used. No apparent problems resulted from feeding sawdust at levels up to 15% to beef cattle.

© American Society of Animal Science 1971