Chemical composition, in vitro digestibility and kinetics of fermentation of whole-crop forage from 18 different varieties of oat (Avena sativa L.)

Abstract

The aim of this study was to compare the yield of forage and the yield of digestible organic matter as well as chemical composition and kinetics of fermentation of forage produced from 18 different varieties of oat (Avena Sativa L.) grown under the same agronomic condition. Dry matter and organic matter digestibility were determined using in vitro two-stage method and gas production technique was used to measure the kinetics of fermentation of forage from different varieties. Yield of forages varied significantly from 15.6 to 26.3 ton ha−1 DM. LGorskij 1026 variety had the highest forage yield. The content of crude protein, neutral detergent fibre (NDF), acid detergent fibre (ADF) and acid detergent lignin (ADL) were significantly (P<0.01) different among varieties of oat used in this study. There were significant (P<0.01) differences among varieties in terms of in vitro dry matter digestibility (IVDMD) and organic matter digestibility (IVOMD) and metabolisable energy (ME) from 18 varieties of oat forage. Possum and LGorskij 1026 varieties had the highest and lowest IVOMD, respectively (67/4 vs. 54/9%). The ME varied from 5.76 to 7.13 MJ kg−1 DM. The mean value of digestible organic matter (DOM) yield was 10.8 ton ha−1. LGorskij 1026 variety had the highest DOM (13.3 ton ha−1). Significant difference was observed in the potential gas production (A), constant rate (c) and lag time among different varieties. The fractional rate of gas production (c, h−1) ranged from 0.029 to 0.040. The result emphasised that in any evaluation of oat varieties, not only yield and digestibility but also kinetics of digestion or fermentation should be taken into consideration.