Effects of various inulin levels on in vitro digestibility of corn silage, perennial ryegrass (Lolium perenne L.) and common vetch (Vicia sativa L.)/oat (Avena sativa L.) hay

Abstract

The aim of this study was to investigate the effects of various inulin levels on in vitro true dry matter digestibility (IVTD^DM) and in vitro neutral detergent fibre digestibility (IVTD^NDF) of corn silage (CS), perennial ryegrass (PR), and common vetch/oat hay (VO). Inulin was added to the fermenter at concentrations of 0 (CSC, PRC, VOC), 100 (CS100, PR100, VO100), 200 (CS200, PR200, VO200), and 300 (CS300, PR300, VO300) mg/litre of total culture fluid using an in vitro DaisyII incubator. Each fermenter contained 1600 ml buffer solution and 400 ml rumen fluid. The IVTD^DM and IVTD^NDF were determined with a DaisyII incubator and rumen fluid obtained from three cannulated Karayaka rams. The IVTD^DM values (%) for PRC, PR100, PR200, and PR300 were 70.06 ± 1.133, 73.21 ± 4.153, 70.36 ± 0.506, and 66.69 ± 1.317, respectively. The effects of various inulin levels on IVTD^DM and IVTD^NDF values of PR were significant (P <0.05). The IVTD^DM and IVTD^NDF values for CS and VO were not significantly (P >0.05) different. Among the treatments, supplementation of inulin to CS and VO did not have a significant (P >0.05) effect on IVTD^DM and IVTD^NDF values. The high dose of inulin (PR300) reduced IVTD^DM and IVTD^NDF, whereas PR100 showed a statistically significant (P <0.05) increase on IVTD^DM and IVTD^NDF. However, in vivo studies with PR may be required to show the effects of various levels of inulin supplementation to support the IVTD findings of the current study.

Keywords: Inulin, in vitro true digestibility, hay, silage