Temporal and vertical distribution of soluble carbohydrate, fiber, protein, and digestibility levels in orchardgrass swards

Griggs, T.C. and Macadam, J.W. and Mayland, H.F. and Burns, J.C. (2007) Temporal and vertical distribution of soluble carbohydrate, fiber, protein, and digestibility levels in orchardgrass swards. Agronomy Journal. 99:755-763.

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Abstract

Herbage nonstructural carbohydrates (NC) contribute to livestock
performance and silage fermentation. Knowledge of the distribution
patterns of NC and other nutritional constituents in orchardgrass
(Dactylic glomerata L.) swards could support harvest management
decisions. Our objective was to determine diurnal and vertical patterns
of total NC (TNC), crude protein (CP), and neutral detergent fiber
(NDF) concentrations, and in vitro true dry matter digestibility
(IVTDMD) and NDF digestibility (NDFD) in orchardgrass swards
in October, June, and August. Herbage was sampled at 6-h intervals
between 0100 and 1900 h from horizons positioned 40 to 27, 27 to
18, 18 to 12, and 12 to 8 cm above soil surface. Herbage composition
varied among horizons in all months, and diurnally only in June
and August. In June and August, only TNC with maxima of 109 to
123 g kg-1 at 1900 h exhibited consistent diurnal patterns. Swards
harvested to residual heights of 18, 12, or 8 cm exhibited little spatial
variation in TNC during June and August, but CP, NDF, and
IVTDMD varied with harvest depth on all dates. As swards were
harvested to successively greater depths, TNC increased in October, but
not in June and August. In contrast, CP and IVTDMD decreased, and
NDF increased, for harvests to successively greater depths in all months.
For harvests in June and August, manipulation of depth would capture
more variation in CP, NDF, and IVTDMD, but manipulation of time of
day of harvest would capture more variation in TNC to meet animal
performance and silage fermentation requirements.

Item Type:	Article
NWISRL Publication Number:	1210
Subjects:	Irrigated crops > Grass forage > Chemistry Mass Import - autoclassified (may be erroneous)
Depositing User:	Dan Stieneke
Date Deposited:	20 Nov 2010 21:49
Last Modified:	01 Nov 2016 15:06
Item ID:	50
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/50