Effect of cooking time and urea level on dry matter loss, nitrogen fixation and digestibility of dry matter, organic matter in vitro in the combined products of urea-pith Gewang (Corypha Utan Lamk.) starch

The purpose of this study was to evaluate dry matter loss, nitrogen fixation and dry matter and organic matter digestibility in vitro from the cooking product of pith Gewang with urea. The treatments applied consisted of cooking time (P) namely 0 hours (P0), 1 hour (P1) and 2 hours (P2) respectively, and the treatment of urea levels namely 0% (U0), 2% (U2) and 4% (U4) respectively, which were combined into 9 treatment combination units, to determine the dry matter loss and nitrogen fixation of the combined product. Determination of digestibility of dry matter and organic matter in vitro of the combined product is the combination of treatment of pith Gewang with urea before adding the control treatment, namely a combination of pith Gewang with urea level without cooking (p0). The research results showed that the dry matter loss of the combined product increased with an increase in the cooking time, but the increase in the urea level decreased the dry matter loss. Nitrogen fixation increased with an increase in the cooking time with urea level. Digestibility of dry matter and organic matter increases with an increase in the cooking time and urea level. It is concluded that, the cooking of pith Gewang with urea level resulted in the combined product that was low in dry matter loss and high in nitrogen fixation, dry matter and organic matter digestibility. Cooking time of 2 hours with urea level of 4 percent is the best combination in producing the combined product.