Roughage buster tubs have a biuret. Biuret is a slow release urea that aids in fiber digestion, especially on poor quality forages. Roughage Buster tubs also have Comax Cobalt. Comax cobalt also aides in forage digestion. 5 trials cows that were wintered on corn stalks and fed corn silage prior to calving weighed 69lbs more and had 10% higher conception than cows fed competitors tubs.