Effects of the source of non-fiber carbohydrates on in vitro first order ruminal disappearance kinetics of dry matter and NDF of various feeds

An in vitro experiment was conducted to study the effect of non-fiber carbohydrates (NFC) on ruminaldisappearance kinetics of dry matter (DM) and neutral detergent fiber (NDF) of alfalfa hay, wheat bran andunmolassed sugar beet pulp. Non-supplemented or NFC supplemented samples [70 mg/g DM of each feedsample as sucrose (SU) or starch (ST) or SU + ST as 1:1] were incubated in bottles containing 40% rumenfluid medium for 4, 8, 16, 24, 48, and 96 h at 39°C. After each incubation time, unfiltered content wasanalysed for DM and NDF. Filtered fluid was analysed for ammonia-N concentration. Kinetic disappearancerate was determined using a first order non-linear model. The source of NFC used in the medium containingalfalfa hay caused a significant decrease in DM disappearance (P