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Livestock Feed Terms
A B C D
E F G H I J K L M
N O P Q R S T U V W X Y Z
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AD LIBITUM (ab lib) Feed offered free-choice, allowing animals to eat as much as
they desire.
AS FED BASIS An expression of feed nutrient content with moisture included.
Nutrient content on an "as fed" basis is always lower than on a "dry matter"
basis.
AVERAGE DAILY GAIN (ADG) The average daily liveweight increase of a growing
animal; usually expressed in kg, g or lb./day.
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BALANCED RATION A 24-hour feed allowance that provides an animal with
appropriate amounts and proportions of all nutrients required for a given level
of performance.
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COLOSTRUM The milk secreted by female mammals for the first few days after
birth. It is particularly rich in nutrients and antibodies essential for newborn
survival.
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DIGESTIBILITY A measure of the extent a feed or nutrient is digested; usually
expressed as a percent.
DIGESTION The changes that occur to a feed within the animal's digestive tract
to prepare it for absorption and use.
DRY MATTER Feed residue left after all moisture has been removed by drying
(i.e., 100% dry matter).
DRY MATTER BASIS An expression of feed nutrient content after the moisture has
been removed by drying. Used to compare nutrient composition or animal intake of
feeds differing in moisture content.
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ENERGY A nutrient essential for maintenance, growth, production and
reproduction. Energy is required in larger amounts than any other nutrient
except water, and is often the limiting factor in livestock production.
ENERGY TERMINOLOGY
Gross Energy (GE) The total combustible energy in a feed,
determined by measuring the amount of heat produced when a feed sample is
completely burnt in a bomb calorimeter.
Digestible Energy (DE) Energy that is available to the animal by digestion;
measured as the difference between gross energy content of a feed and the energy
contained in the animal's feces (gross energy minus fecal energy.)
Metabolizable Energy (ME) A measure of the useful energy in a feed. It
represents that portion of the feed gross energy not lost in the feces, urine
and belched gas.
Net Energy (NE) The amount of feed energy actually available for animal
maintenance and production. It represents the energy fraction in a feed left
after fecal, urinary, gas and heat losses are deducted from the gross energy
value of a feed.
Total Digestible Nutrients (TDN) A term describing the energy value of
feedstuffs, comparable to DE in accuracy. TDN over- estimates the energy value
of roughages in comparison to grains.
ENERGY MEASUREMENTS
Calorie A measure of energy; usually expressed as
kilocalorie (kcal) or megacalorie (Mcal). 1 cal = the amount of energy required
to increase the temperature of 1 g of water 1 degree C.
Joule A unit adopted by Systeme International (SI) for expressing energy. The
Joule is more commonly used in Europe than in North America (4.184J = 1
calorie).
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FAT A term used in a general sense to refer to both fats and oils. Fat supplied
2.25 times as much energy as carbohydrates. Both fats and oils share the same
general structure and chemical properties, but have different physical
properties, i.e., oils are liquid at room temperature.
FAT TERMINOLOGY
Protected Fat A fat that has been treated or combined with
another substance to prevent breakdown in the rumen.
Saturated Fat A completely hydrogenated fat. Saturated fats are solid at room
temperature. Example: animal tallow.
Unsaturated Fat Any fat that is not completely hydrogenated. Unsaturated fats
are liquid at room temperature. Examples: corn oil, vegetable oil.
FEED (FEEDSTUFF) An edible material that contributes nutrients to animals'
diets.
FEED ADDITIVES Products added to basic feed mixes to improve the rate and/or
efficiency of gain, prevent certain diseases, or preserve feeds. A partial
listing includes:
Antibiotic A class of drug usually produced by living organisms (molds, bacteria
or green plants), which can inhibit or kill undesirable bacteria. Example:
penicillin.
Buffer A substance used in livestock rations to help resist changes in the
acidity of the digestive tract. Examples: sodium bicarbonate, bentonite.
Direct Fed Microbials (Probiotics) A live microbial feed supplement which
beneficially affects the host animal. Claims include reduced early mortality,
increased growth rate, improved feed conversion, egg quality and animal health.
Enzyme A complex protein compound produced in living cells which speeds up
chemical reactions without itself being changed or destroyed. It is added to
animal feeds to supplement low enzyme production by some young animals or to
improve utilization of feeds.
Ionophore A carboxylic polyether antibiotic that affects the transport of ions
across cellular membranes and inhibits the growth of some gram positive
bacteria. It is used in growing cattle to enhance feed efficiency and stimulate
growth. Examples: Bovatec, Rumensin.
Melangestrol Acetate (MGA) A hormone added to diets to suppress estrus cycling
and improve feed efficiency and growth rate in feedlot heifers.
Yeast/Yeast Culture A single cell fungi which improves feed digestion by
stimulating microbial activity and stabilizing digestive tract pH. Products
packaged as "yeast" consist of cells only; "yeast culture" includes live yeast
cells plus growth media.
FEED CLASSIFICATION Browse Small stems, twigs, leaves and/or fruits and flowers
of shrubs, woody vines and trees.
Byproduct Feeds produced as a result of industrial manufacturing, plant or
animal processing. Examples: distillers grains, beet pulp, meat and bone meal,
fish meal.
Chaff Husks or other seed coverings and other plant parts separated from seed
during harvest or processing.
Complete Feed A thoroughly blended mixture of different feed ingredients
formulated to meet specific nutrient requirements.
Concentrate A classification of feedstuffs high in energy and low in fibre;
usually further divided into energy and protein concentrates. Often used
interchangeably with supplement. Examples: corn, barley, soybeans.
Forage Plants or plant parts fed to, or grazed by, domestic animals. Forage may
be fresh, dry or ensiled (i.e., pasture, green chop, hay, haylage). Often used
interchangeably with roughage.
Liquid Protein Supplement (LPS) A protein product usually containing molasses,
urea, added vitamins and trace minerals; particularly useful in pasture feeding.
Milk Replacer A substitute for fresh whole milk, fortified with vitamins,
minerals and sometimes antibiotics; used as a nutrient source for young animals.
Mineral Supplement A rich source of one or more mineral elements.
Premix A uniform mixture of one or more microingredients and a carrier, used to
facilitate uniform dispersion of micronutrients into a larger mixture.
Protein Supplement A feed or mixture of feeds containing 20% or more protein.
Examples: soybean meal, canola meal.
Roughage A term used to describe a feed high in fibre (greater than 18% crude
fibre). Roughage tends to be bulky, coarse, and low in energy. Examples: hay,
silage, straw.
Silage Feed preserved by an anaerobic fermentation process. Examples: corn
silage, haylage, high moisture corn.
Screenings Small, imperfect kernels, broken grains, hulls, weed seeds and other
foreign material obtained from the cleaning of grain.
Supplement Feed or feed mixtures rich in one or more of protein, energy,
vitamins, minerals or antibiotics. Combined with other feeds to produce a more
complete feed.
Sweet Feed A commercial feed sweetened with molasses to improve palatability.
Total Mixed Ration (TMR) All ration ingredients, including roughages, mixed
mechanically to provide one homogenous mixture. TMRs are used in large dairy or
beef feedlot operations.
FEED EFFICIENCY A ratio describing the amount of feed required per unit of
production (grain, milk, eggs).
FEED GRADE Term to describe the quality of feedstuffs suitable for animal, but
no human, consumption.
FEED PROCESSING Physical or chemical changes in feedstuffs which influence their
nutritional value.
FLUSHING The practice of increasing a female animal's energy intake prior to and
during the breeding season; may increase conception rate and/or litter size.
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HAY ADDITIVES Organic acids or acid-forming compounds designed to allow hay to
be harvested at higher than normal moisture contents by preventing the microbial
activity responsible for spoilage.
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LABORATORY TESTS
Acid Detergent Fibre (ADF) The amount of residue (primarily
cellulose, lignin and variable amounts of silica) left after boiling a feed
sample in an acid detergent solution. The ADF value is used to predict the
energy content (TDN, NE) of forages.
Acid Detergent Fibre - Nitrogen (ADF-N)/Acid Detergent Insoluble Nitrogen (ADIN)
A laboratory test used to measure the amount of heat damaged protein in hay and
haylage.
Ash The inorganic mineral elements of animals and plants, determined by burning
off the organic matter and weighing the residue (ash).
Crude Protein An estimate of the total protein content of a feed; determined by
analyzing the nitrogen content of the feed and multiplying the result by 6.25 Crude protein includes true protein and other nitrogen-containing substances
such as ammonia, amino acids, nitrates.
Ether Extract Laboratory test to measure the total fat content of a feed.
Neutral Detergent Fibre (NDF) The insoluble fraction containing all plant cell
wall components left after boiling a feed sample in a neutral detergent
solution. NDF is of low digestibility, but can be broken down somewhat by the
digestive tract microorganisms. NDF value is used to predict ruminant feed
intake.
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MEASUREMENTS
Gram (g) 1/1000 of a kilogram (kg) or 1/28 ounce (28 grams = 1
ounce). A very small unit of weight.
International Unit (IU) A standard unit of potency of a biological agent.
Example: vitamin, hormone, antibiotic, antitoxin. Also called a USP unit.
Kilo A prefix used in the metric system of measurement to represent one
thousand. Example: 1 kilogram (kg) = 1,000 grams, 1 kilojoule (KJ) = 1,000
joules.
Mega A prefix used in the metric system of measurement to represent one million.
Example: 1 megacalorie (Mcal) = 1,000,000 calories.
Milli A prefix used in the metric system of measurement to represent 1/1,000.
Example: 1 mg = 1/1,000 g.
Parts per Million (ppm) A measurement used for nutrients present in very small
quantities (example: microminerals); ppm = milligrams per kilogram (mg/kg) or
millilitre per litre (ml/l).
pH A measure of acidity or alkalinity. Values range from 0 (most acidic) to 14
(most alkaline or basic). A pH value of 7.0 is neutral (neither acidic or
alkaline).
METABOLISM All of the chemical changes nutrients undergo following absorption
from the digestive tract.
MICRONUTRIENT Any ingredient, such as minerals, vitamins or drugs, added in very
small amounts to a ration.
MONOGASTRIC An animal having a single or simple stomach system. Example: swine.
MYCOTOXIN A substance produced by fungi and toxic to animals, e.g., vomitoxin,
zearalenone and aflatoxin.
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NON-RUMINANT HERBIVORE Animals with simple stomachs able to digest roughages and
other fibrous feeds because of the microbial population in their hindgut.
Examples: horse, rabbit.
NUTRIENTS Feed components required for the maintenance, production and health of
animals (water, carbohydrates, lipids, proteins, minerals and vitamins.
Carbohydrates Major energy providing substrates including starches, sugars,
cellulose and hemicellulose. All carbohydrates contain carbon, hydrogen and
oxygen, and are usually divided into two fractions - structural (fibre) and
non-structural (sugars and starches).
Non-Structural (Non-Fibre) Carbohydrates (NSC or NFC) Simple carbohydrates, such
as starches and sugars, stored inside the cell which serve as a cellular energy
source. Non-structural carbohydrates are rapidly and easily digested by the
animal.
Structural Carbohydrates (Fibre) Complex carbohydrates including cellulose,
hemicellulose, lignin and pectin that form the plant cell wall. Measured in the
laboratory as neutral detergent fibre (NDF).
Lipids Substances found in plant and animal tissues that are insoluble in water,
but soluble in benzene or ether. Includes fats, oils, glycolipids,
phosphoglycerides, waxes and steroids.
Minerals Inorganic feed elements essential for life.
Macro (or Major) Minerals Minerals required in relatively large amounts by
livestock. Includes calcium (Ca), phosphorus (P) magnesium (Mg), potassium (K)
chlorine (Cl), sulfur (S) and sodium (Na).
Micro (or Trace) Minerals Minor mineral elements required in very small amounts
in the ration of animals. Includes manganese (Mn), copper (Cu), zinc (Zn),
selenium (Se) iron (Fe), cobalt (Co), iodine (I) and fluorine (Fl).
Protein Naturally-occurring compounds containing nitrogen, carbon, hydrogen and
oxygen, and sometimes sulfur or phosphorus. Proteins are made up of complex
combinations of amino acids and are essential for animal growth, production and
reproduction.
Amino Acids Nitrogen-containing compounds that are the building blocks from
which protein are made.
Available Protein The portion of the crude protein that can be used by the
animal.
Essential Amino Acids Amino acids that must be supplied in the diet, as the
animal either cannot synthesize them or cannot synthesize them in sufficient
quantities to meet requirements.
Estimated Crude Protein from Non-Protein Source (ECP from NPS) Non-protein
nitrogen sources such as urea or ammonia; used in ruminant diets in limited
amounts to enhance dietary protein levels.
Non-Essential Amino Acids Amino acids that can be synthesized by the animal.
Non-Protein Nitrogen (NPN) Nitrogen not derived from true protein, but can be
used by rumen microbes to build microbial protein.
Degradable Intake Protein (DIP) Portion of intake protein that is degraded
(broken down) by rumen microbes to ammonia and amino acids. DIP is used for
microbial synthesis.
Undegradable Intake Protein (UIP) Portion of ingested protein that escapes rumen
degradation and is digested directly in the other stomachs or small intestine;
generally a more expensive source of protein. Commonly referred to as 'bypass'
protein.
Soluble Intake Protein (SIP) Portion of the protein intake that is completely
soluble in rumen fluid and rapidly utilized by bacteria. Soluble protein forms
part (or all) of the degradable intake protein (DIP) value of a feed.
Unavailable Protein/Heat Damaged Protein Portion of the protein irreversibly
bound to the fibre fraction in feedstuffs. It is usually a small fraction of the
total protein, but can be greatly increased by heat.
Vitamins Organic compounds that function as parts of enzyme systems essential
for many metabolic functions.
Fat Soluble Vitamins Includes vitamins A, D, E and K. Vitamins A, D and E are
supplemented in many livestock rations. Fat soluble vitamins are stored in body
fat reserves.
Water Soluble Vitamins Includes B complex vitamins and vitamin C. Not normally
supplemented for ruminants after two months of age because rumen microbes are
able to manufacture enough to meet the animal's requirements.
NUTRIENT ALLOWANCES Recommendations of nutrient amounts necessary for
maintenance, growth, gestation, lactation or performance that include a safety
margin to account for variability in feeds and animals (e.g., environment,
health, storage losses).
NUTRIENT REQUIREMENTS The minimal amounts of nutrients (energy, protein,
minerals and vitamins) necessary to meet an animal's minimal needs for
maintenance, growth, reproduction, lactation or work.
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PALATABILITY The appeal and acceptability of feedstuffs. Affected by the taste,
odour, texture and temperature of the feed.
PARTICLE SIZE Measure of the diameter of granular feed materials and/or the
length of roughage fragments. Particle size can affect mixing of feed
ingredients and digestion rate.
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RATION The 24-hour feed allowance for an individual animal.
RUMINANT A cud-chewing animal having four stomach compartments. The rumen (first
stomach), is a major site of microbial fermentation of feeds permitting
breakdown of fibre. Examples: cattle, sheep, goats.
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SILAGE ADDITIVES Substances added during the ensiling process to enhance the
correct and rapid fermentation of the feed.
last edit August 22, 2002
last edited
August 17, 2004
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