Elephant grass, rice straw and maize silage as feeds: A dynamic modelling approach on their degradation kinetics

Abstract

This study aimed to evaluate nutritive value of elephant grass, rice straw and maize silage by using a dynamic modelling approach. Data on dry matter (DM) degradation characteristics were compiled, i.e., soluble (S), degradable (D) and undegradable (U) fractions, and rate of degradation of the degradable fraction (kd). Each of the S, D or U fraction was assumed to have a specific rate of passage (kp). The S, D and U fractions are dynamically changed over time. Degraded S and D fractions form a pool namely cumulative S and D (CSD) and it dynamically increases over time. Integration of all the dynamic models was performed in Vensim software version 7.3.5 using the Euler method. Results revealed that soluble fraction present in elephant grass, rice straw and maize silage disappeared within early hours in the rumen. The degradable fraction of maize silage was degraded more rapidly than that of elephant grass and rice straw. Maize silage had the highest potential CSD as compared to those of elephant grass and rice straw. It can be concluded that, based on the dynamic modelling approach, maize silage has higher nutritive value for ruminant livestock, followed by elephant grass and then rice straw.