Urea treatment of rice straw at elevated temperature and pressure: Effects on fiber content, rumen fermentation and digestibility
Abstract: The objective of
this study was to apply urea treatment of rice straw at elevated temperature
and pressure (121oC; 1.4 atm) and at short treatment period (30 or 60 min) in
comparison to conventional urea treatment (4 weeks incubation). Rice straw was
subjected to the following treatments: RS1: untreated rice straw (control),
RS2: RS1+1% urea (no incubation), RS3:RS1+1% urea (4 weeks incubation), RS4:
RS2+autoclave 30 min, RS5: RS3+autoclave 30 min, RS6: RS2+autoclave 60 min,
RS7: RS3+autoclave 60 min. The samples were analyzed for fiber contents and
incubated in vitro. Data were analyzed using analysis of variance and Duncan’s
post-hoc test. Results showed that urea treatments (RS3-RS7) did not change NDF
and ADF contents of rice straw in comparison to control. Urea treatment in
autoclave for 30 min (RS4) increased rice straw IVDMD and IVOMD by 23.3% and
25.6% as compared to control, respectively (P<0.05). Extension of the
incubation period to 60 min (RS6) did not improve further the IVDMD and IVOMD.
Treatments did not change pH values and NH3 concentrations. Urea treatment
(RS3-RS7) increased total VFA concentration in comparison to control
(P<0.05). It was concluded that urea treatment using autoclave for 30 min
may replace conventional urea treatment to improve nutritional value of rice
straw.
Keywords: urea treatment; rice
straw; fiber; digestibility; rumen
Author: A. Jayanegara, R. S.
K. Ayinda, E. B. Laconi
Journal Code: jppeternakangg170016
