The Effect of Different Methods of Processing on Nutritive Value and Degradation of Rice Straw by Rumen Mixed Bacteria
The aim of this study was to evaluate rumen bacteria activity on degradation of untreated Rice Straw (RS) and treated with low temperature steam, sodium Hydroxide (NaOH) and exogenous enzyme using disappearance of Dry Matter (DM) and Neutral Detergent Fiber (NDF) in rumen bacteria culture for 96 h incubation. Treatments were including; untreated RS, RS treated with low temperature steam (120°C for 120 min), RS treated with 80 g kg-1 DM NaOH, RS treated with 20 g kg-1 DM exogenous enzyme and RS treated with enzyme+NaOH. The result showed disappearance of dry matter after 96 h incubation by rumen bacteria was 60.3, 75.2, 85.3, 81.3 and 96.2 g/100 g for untreated rice straw and treated with steam, NaOH, enzyme and enzyme+NaOH, respectively. Sodium hydroxide, enzyme and steam caused to increase disappearance NDF of rice straw in media culture in compared with the other samples, 96 h after culturing and the highest increase of NDF disappearance was for rice straw treated with enzyme+NaOH (345.3 mg g-1) (p<0.05). Therefore, it may be resulted that low temperature steam, exogenous enzyme and NaOH influence the growth and activity of rumen bacteria on rice straw in compared to untreated RS.