In vitro digestibility of fermented rice straw combined with different levels of green concentrate

Abstract

One way to further improving the nutritive value of fermented rice straw (FRS) is by combining it with a high-quality feedstuff such as green concentrate. The purpose of this study was to assess the in vitro dry matter digestibility (IVDMD) and in vitro organic matter digestibility (IVOMD) of FRS mixed with different levels of green concentrate prepared from different legume trees. The study was carried out according to a completely randomized design consisting of 10 treatments and three replications. The treatments were C = 100% FRS (control), A1 = 90% FRS + 10% Gamal meal, A2 = 80% FRS + 20% Gamal meal, A3 = 70% FRS+ 30% Gamal meal; B1 = 90% FRS + 10% Lamtoro meal, B2 = 80% FRS + 20% Lamtoro meal, B3 = 70% FRS + 30% Lamtoro meal, C1 = 90% FRS + 10% Indigofera meal, C2 = 80% FRS + 20% Indigofera meal, and C3 = 70% FRS + 30% Indigofera meal. Data analysis indicated that IVDMD and IVOM of FRS (control) was much less (P<0.05) than those of FRS combined with green concentrate. Among the green concentrate treatments, the IVDMD and IVOMD of FRS mixed with either Lamtoro or Gamal meal were less (P<0.05) than those of FRS combined with Indigofera meal, while IVDMD and IVOMD of FRS + Gamal meal were similar (P>0.05) to those of FRS + Lamtoro meal. Within each legume meal, the IVDMD and IVOMD significantly increased (P<0.05) as the level of legume meal in the mixture increased. In conclusion, the nutritive value of fermented rice straw could be boosted through substituting some of the FRS with green concentrate and among three different legume meals used as a green concentrate, the use of Indigofera meal resulting in the biggest improvement in terms of IVDMD and IVOMD compared with the use either Gamal or Lamtoro meal.