NR 34. In vitro fermentation of lignocellulosic forages using different sources and levels of carbohydrates as supplement

Abstract

The effect of the source and level of carbohydrate supplementation on microbial fermentation of roughages was studied in vitro by the gas production technique. Tested supplements (starch, A; pectin, P and cellulose, C) were included at 0, 15, 30, 45 and 60 % of the substrate (ammoniated straw, 200 mg) in duplicates. The amount of gas produced by the supplements themselves was substracted from the straw + supplement volume, according to the results of an additional set of incubation. Comparison among the effects of supplements was performed in pairs, in three sets of incubation. The higher amount of gas produced from straw was obtained with P (P<.05), whereas the effect of A was not different from C (P>.05). There was no negative response to increasing levels of P, but increases of A and C linearly reduced gas production from straw