DIGESTIBILITY BY DAIRY-COWS OF MONOSACCHARIDE COMPONENTS IN DIETS CONTAINING EITHER GROUND SORGHUM OR SORGHUM GRAIN TREATED WITH SODIUM-HYDROXIDE

Five cows in midlactation and equipped with ruminal and abomasal canul as were fed two isonitrogenous diets composed of 46% sorghum grain, ei ther ground or treated with 4% NaOH, plus 39% wheat silage and 15% sup plements. The DMI were 16.3 and 15.8 kg/d for cows fed the diets conta ining ground sorghum and treated sorghum, respectively. The digestibil ity of NDF polysaccharides was higher far cows fed the treated sorghum , but the digestibility of neutral detergent soluble alpha-glucans (st arch) was higher for cows fed ground sorghum. Digestibility of total c arbohydrate was 79% for cows fed the diet containing ground sorghum an d 67% for cows fed the diet containing sorghum treated with NaOH. Rumi nal pH was higher in cows fed the diet with treated sorghum, but total ruminal VFA concentration was higher in cows fed the diet containing ground sorghum. Profiles of individual ruminal VFA and NH3 concentrati on were similar for both treatments. Flow of NAN through the abomasum of cows fed ground sorghum was higher than that of cows fed the sorghu m treated with NaOH, and N absorption in the intestine followed a simi lar trend. The data indicated a possible advantage for dairy cows fed ground sorghum than for those fed grain treated With NaOH.