Comparison of the volatile fatty acid profiles of dry and fresh kikuyu incubated with rumen fluid in vitro

Abstract

Volatile fatty acids (VFA) are produced from the fermentation of feed organic matter by rumen microbes. In general, the quantity of VFA produced corresponds to the amount of fermentable organic matter ingested and the ratio of acetate: proportionate (C2:C3) produced is altered by the rate of fermentation (Boss et at. 1996). In this study we investigated the VFA profiles of kikuyu ('Pennisetum clandestinum') processed in three different ways before being incubated in vitro with bovine rumen fluid for 2.5 h. The three treatments were fresh (FRK), freeze dried (FDK) and oven dried (ODK) kikuyu . Samples of FRK (25 g fresh, 5 g dry matter) were chopped into 2-3 cm lengths whereas for FDK and ODK, 5 g dried material (1 mm sieve) was incubated with butter and rumen fluid (Damry 2002).