The study aimed to evaluate the digestibility of ration-containing corncobs soaked in rice hull ash filtrate. The research was conducted experimentally using a descriptive method and complete randomized design (RAL) followed by the Duncan test. Analysis of mineral rice hull comes from three locations in three different regencies in West Java. Corncobs were soaked with rice hull ash filtrate with a ratio of 1: 1 for three hours with four different concentrations, ie RHAF 1 = 0.05 w/v, RHAF 2 = 0.1 w/v, RHAF 3 = 0.15 w/v, and RHAF 4 = 0.2 w/v. In vitro, evaluation was used to measure the fermentability and digestibility of ration-containing corncobs soaked by ash hull ash filtrate (0.2 w/v) at CSRHAC 1 = 10%, CSRHAC 2 = 20%, CSRHAC 3 = 30%, and CSRHAC 4 = 40%. The results show that rice hull ash contains alkaline minerals of calcium (Ca), potassium (K), magnesium (Mg), and sodium (Na) with potassium having the highest value with an average of 0.522%. Dissolving rice husk ash with distilled water produces an alkaline filtrate and forms a linear regression equation, namely Y = 3.3X + 8.45, R2 = 0.7806. The highest pH value achieved in RHAF 4 of 9.15±0.13. The levels of NDF, ADF, cellulose, hemicellulose, and crude fiber decreased significantly (P <0.05) while rice hull ash filtrate concentrations increased. The highest decrease in ADF and NDF was achieved at concentrations of 0.2 w/v. The use of corncobs with rice hull ash filtrate soaked by 0.2 w/v (RHAF 4) in rations resulted in differences between treatments (P <0.05). CSRHAC 2 gave the highest (P <0.05) of DMD, OMD, N-NH3, and VFA among the treatments, namely 52.65±0.73%, 44.76±1.38 %, 2.68±0.10 mM, and 115.80 mM. Thus, it concluded that processing of corncobs with rice hull ash filtrate at concentrations of 0.20 w/v resulted in maximum decreased ADF and NDF and its use of 20% in rations yielded the best in vitro digestibility and fermentability.
Keywords | Ash, Corncob, Digestibility, Fermentability, In vitro, Rice hull