In vitro gas production and digestibility of oil palm frond silage mixed with different levels of elephant grass

Abstract

Oil palm frond (OPF) is an agricultural by-product which abundantly available in Indonesia. Study to enhance its nutritive value and to preserve OPF is necessary. Ensiling is widely used for preserving biomass with addition of lactic acid bacteria as inoculant. Further, to improve nutritive value of OPF, it is ensiled mixed with grass. This research was conducted to evaluate the effect of addition of elephant grass (Pennisetum purpureum) in OPF mixed silages on in vitro gas production and digestibility. Treatments were proportion of elephant grass started from 0, 20, 40, 60, and 100%. Higher grass portion in OPF mix silage decreased pH, increased total acid and lactic acid bacteria (LAB). Highest total gas and maximum gas production were 90.38 mL and 99.50 mL, both resulted from S4 (100% grass). Higher portion of grass increased methane production. Highest methane production was 6.38 %, resulted from S4 (100% grass), significantly higher (p<0.05) than other treatments. The lowest methane production, 1.50% was produced from 100% OPF silage (S0). Highest dry matter and organic matter digestibility were62.55% and 62.53%, resulted from 100% grass silage (S4). It was concluded that optimum composition of mixed silages for rumen fermentation was OPF 80%+elephant grass 20%.