Conclusions and recommendations
Based on this study, it could be concluded that the use of urea plus calcium hydroxide could improved the nutritive value of rice straw in terms of dry matter intake, digestibility, ruminal volatile fatty acids, ruminal microbial population, N retention and microbial protein synthesis in beef cattle. Combination of urea plus Ca(OH)2 was an important alternative to only urea treatment which reduced feed cost in ruminant feeding.