Digestibility, Nitrogen Retention and Energy Values of Sorghum Grain and Corn Rations at Three Levels of Intake

Finely-ground sorghum grain and corn were compared in digestion and metabolism trials with steers. In trial 1, digestibility of ration components, digestible energy, metabolizable energy and nitrogen retention were determined on a basal diet which was common to all subsequent treatments. In trials 2, 3, and 4, sorghum grain and corn were each combined with the basal diet and fed at maintenance, intermediate and high levels of intake; two animals appeared on each treatment in each of the three trials. Corn or sorghum grain furnished one-half of the feed in the maintenance ration, while the remainder was the basal. In the intermediate and high levels, corn and sorghum grain were each added to the basal diet, which was fed at a maintenance level. Differences in the digestibility of proximate components in the entire rations were not significant between grains or among levels of each. Digestibilities, as determined “by difference”, of organic matter and protein were significantly higher in corn than in sorghum grain. Differences in digestible and metabolizable energy values were not significant among levels or between grains. Nitrogen retention was significantly higher for the intermediate and higher than for the maintenance level, there were no significant differences between the grains. The results of this study indicate that sorghum grain is comparable to corn in digestibility of proximate components, digestible energy, metabolizable energy and nitrogen retention.