Glossary | Forage Information System

Define terms to be used throughout the site

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Click one of the letters above to be taken to a page of all terms beginning with that letter.

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).