ORIGINAL PAPER
Prediction of NDF degradation characteristics of
grass and grass/clover forages based on laboratory
methods
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1 |
Danish Institute of Agricultural Sciences, Department of Animal Nutrition and Physiology,
P.O. Box 50, DK-8830 Tjele, Denmark |
2 |
University of South Bohemia, Faculty of Agriculture, Department of Genetics,
Breeding and Animal Nutrition,
Studentská 13, 370 05 České Budějovice, Czech Republic |
CORRESPONDING AUTHOR
M. R. Weisbjerg
Danish Institute of Agricultural Sciences, Department of Animal Nutrition and Physiology,
P.O. Box 50, DK-8830 Tjele, Denmark
Publication date: 2004-10-25
J. Anim. Feed Sci. 2004;13(4):691–708
KEYWORDS
ABSTRACT
The degradation profiles of neutral detergent fibre (NDF) for typical Danish forages (25 grass
and grass/clover samples) were evaluated using rumen nylon bag incubations.
In vitro digestibility of organic matter (OM) and NDF was performed by two different standard
laboratory methods, one based on Tilley and Terry rumen fluid (T and T) and one on enzymes (ENZ).
Concentrations of NDF, acid detergent fibre (ADF) and acid detergent lignin (ADL), ash and crude
protein (CP) in feeds were determined. The ability to predict in situ potential NDF degradability and in situ fractional rate of NDF degradation based on in vitro digestibilities and on chemical analyses was tested using multiple regression analysis. A considerable variation was found in NDF degradation between samples. The indigestible NDF (INDF) proportion was determined after 504 h in situ incubation and ranged from 0.047 to 0.246 of NDF. Fractional rate of NDF degradation (c) varied from 0.022 to 0.150 per hour. The
potential degradable NDF fraction (b) showed high correlation with ADL content and ADL/NDF
ratio. Fractional rate of degradation (c) showed the highest correlation with in vitro enzymatic NDF
digestibility (ENZNDF) and NDF and ADL content. This shows that potential degradability of NDF is mostly correlated to lignification of fibre, whereas fractional rate of degradation is mostly correlated
to digestibility. It was possible to describe 0.87 of the variation in the potentially degradable NDF fraction (b) and
0.83 of the variation in fractional rate of degradation (c) using all available information on the feeds.
Equations based on in vitro OM digestibility and chemical analyses described 0.83 and 0.85 of the variation in b and c, respectively, and equations based only on NDF content and calculated in vivo OM digestibility (sheep) were able to describe approximately 0.80 of the variation in b and c.
CITATIONS (2):
1.
Effect of diet composition and incubation time on feed indigestible neutral detergent fiber concentration in dairy cows
S.J. Krizsan, P. Huhtanen
Journal of Dairy Science
2.
Assessment of in situ techniques to determine indigestible components in the feed and feces of cattle receiving supplemental condensed tannins1
Aaron Norris, Luis Tedeschi, James Muir
Journal of Animal Science