Effect of Added Carbohydrate on the Utilization by Steers of Nitrogen in Wintering Rations

Abstract

In a series of three experiments, digestion and nitrogen balance trials were conducted with steers to determine the effect of adding different amounts of cerelose to wintering rations containing approximately 8, 10 and 12 percent protein. The basal wintering rations were composed of prairie hay, cottonseed meal and minerals in the proportions frequently fed to wintering beef cattle. Additions of cerelose to the extent of 350, 700 and 1050 gm. to the 8-percent ration, and 700 and 1050 gm. to the 10- and 12-percent rations, resulted in a significant depression in nitrogen retention when the basal ration contained 8 percent protein, a significant increase in nitrogen retention when the basal ration contained 10 percent protein, and a small but not statistically significant increase when the basal ration contained 12 percent protein. The added cerelose increased the estimated (Thomas-Mitchell) biological value of the nitrogen of all three basal rations. It decreased the apparent, but not the true, digestibility of protein, depressed the digestibility of crude fiber, and increased the digestibility of nitrogen-free extract. At each level of protein, the trend of results was toward an increase in these effects with increasing cerelose intake.