Forage Information System, Oregon State University
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Glossary

Define terms to be used throughout the site

a
abaxial
Located on the side away from the axis (e.g., the undersurface of a leaf).
abiotic
Nonliving components of the environment, such as water, solar radiation, oxygen, organic compounds, and soil nutrients.
abomasum
The fourth compartment of the ruminant stomach, comprising the true stomach, in which occur digestive processes similar to those found in the nonruminant stomach.
acceptability
Readiness with which animals select and ingest a forage; sometimes used interchangeable to mean either palatability or voluntary intake.
acid detergent fiber
Insoluble residue following extraction of herbage with acid detergent (ban Soest); cell wall constituents minus hemicellulose.Synonyms: ADF
acid detergent fiber digestibility
The digestibility of acid detergent fiber (ADF) of a forage, as determined by the percentage decrease in ADF measured before and after in vitro or in vivo digestion
acid detergent lignin
Lignin in the residue determined following extraction with acid detergent.Synonyms: ADL
acid pepsin
Used is second stage of in vitro forage digestion, 2 g of 0.1 g kg-1 pepsin in 1 L of 0.1 M HCI.
ad libitum feeding
Daily feed offerings that allow free-will consumption, generally fed to have a daily excess of 15% of feed remaining.
adaxial
Located on the side toward the axis (e.g., the upper surface of a leaf).
adventitious roots
The second root system which develops from the lower nodes of each grass tiller; seminal roots, the primary roots, develop from embryo primordia but are short lived.
aerobic
Pertaining to life or processes occurring in free oxygen or in oxygen concentrations normal in air (21% O2). See also anaerobic
aflatoxin C17H10O6
A polynuclear substance derived from molds; a known carcinogen. It is produced by a fungus occurring on peanuts, corn , and other plants, especially seeds.
aftermath
Residue and/or regrowth of plants (forage) used for grazing after harvesting of a crop.
agro-silvo-pastoral
Land use system in which woody perennials are grown with agricultural crops, forage crops, and livestock production.
agroforestry
Land use system in which woody perennials are grown for wood production in association with agricultural crops, with or without animal production, or other commercial enterprises.
agrostology
agrostology Study of grasses; their classification, management, and utilization.
alkaloid
One of a class of basic organic compounds with nitrogen in their structure; a secondary product of plant metabolism. An example is perloline, produced by tall fescue.
allelopathy
The positive or negative influence of living plant upon another due to secretion of chemical substances. See autotoxicity.
amylopectin
The form of starch in which branching occurs through alpha 1-6 linkages from an amylose backbone. Amylopectins are more easily dissolved and digested than amylose. The contents of amylose and amylopectins in seed grains are genetically controlled.
amylose
amylose The form of starch in which linkages are exclusively alpha 1-4. While representative formulas usually are presented in a linear fashion, the molecules actually have a spiral form.
anaerobic
anaerobic Living in the absence of free oxygen; the opposite of aerobic.
annual
annual A plant that completes its life cycle and dies within a year.
anoxia
Oxygen deficiency.
anthesis
Stage in floral development when pollen is shed from anthers. With self-pollinating species, anthesis occurs prior to the seapration of the lemma and palea.
antiquality constituents
Constituents that have negative effects on forage intake or that produce negative responses in animals consuming the produce containing the constituent.
apical dominance
Inhibiting effect of a terminal bud upon the development of lateral buds.
apomixis
Formation of viable embryos without actual union of male and female gametes, as in Kentucky bluegrass.
ash
The residue remaining after complete burning of combustible matter; consists mainly of minerals in oxidized form.
auricle
A leaf appendage; adjacent to the collar between the blade and the sheath, a claw-like lobe at the base of leaf blades of certain grass species.
autotoxicity
A specific type of allelopathy where the presence of adult plants interferes with the germination and development of its own seedlings.
awn
A stiff bristle. Used in the Asteraceae for a pappus of stout bristles or hard needle-like structures. Used in the Poaceae for the bristley appendages often borne on glumes and lemmas. Sometimes called a beard.
awned
Having an awn.
awnless
Not having an awn.
axillary bud
Meristematic apex located in the junction of the leaf and stem; gives rise to tillers in grasses and to branches and flowers in dicots.
axis
The middle of the structure (e.g., the rachis of a compound leaf, the center of a compound ovary).