1987 Volume 58 Issue 6 Pages 483-489
It is considered that rice straw which contains a large proportion of characteristic insoluble components is digested more slowly than forages of high quality, when in vitro digestion methods are adopted.This study aimed to determine the optimum incubation time in both the rapid cellulase method and the artificial rumen method, and the following results were obtained.
1.The in vitro dry matter digestibility (IVDMD) determined by the rapid cellulase method was much increased with incubation time up to two hours, but was still lower than the in vivo dry matter digestibility.
2.IVDMD determined by the artificial rumen method was not stabilized over 72 hours of incubation, and also it varied with the rumen fluid inocula taken from wethers under different feeding regimes.
3.IVDMD determined after the two-hour incubation by the rapid cellulase method and also that after the 72-hour incubation by artificial rumen method were highly correlated with in vivo dry matter digestibility. Correlation coefficients were 0.954 (P<0.01) and 0.899 (P<0.01), respectively.
4.It is concluded that the rapid cellulase method would be proper to estimate the nutritive value of rice straw in vitro, and the optimum incubation time would be two hours in applying this method to rice straw.
