Absorption - The movement of nutrients (or other compounds) from the digestive tract (or through other tissues such as the skin) into the blood and/or lymph system.

Acidification - The act of reducing the pH of a substance or solution; or increasing the acidity.

Acidosis - A condition in ruminants where excess acid from the rumen is absorbed into the blood stream causing a lowered bicarbonate concentration.

Additive - An ingredient or combination of ingredients added in small quantities to a basic feed mix for the purpose of fortifying the basic mix with trace nutrients, medicines or drugs.

ADF - Acid detergent fiber. Fiber measurement extracted with acidic detergent in a technique employed to help appraise the quality of forages. Includes cellulose, lignin, ADIN and acid-insoluble ash. The ADF value is important because it relates to the ability of an animal to digest the forage. As ADF increases, the ability to digest or the digestibility of the forage decreases.

ADIN - Acid detergent insoluble nitrogen. Protein or nitrogen that has become chemically linked to carbohydrates to form an indigestible compound. Also referred to as insoluble crude protein (ICP), unavailable protein or heat-damaged protein.

Albumin - A group of globular proteins; a major component of blood serum protein.

Amino Acids - The building blocks of proteins. They are used extensively for milk and muscle protein synthesis. Used also for glucose synthesis in the liver.

Anemia - A deficiency in the blood of red cells, hemoglobin, or both.

Anorexia - Lack or loss of the appetite for food.

Anoxia - Oxygen deficiency.

Antibiotic - A substance produced by one microorganism that has an inhibitory effect on another microorganism.

Antioxidant - A substance that inhibits the oxidation of other compounds.

Antivitamin - A substance that interferes with the synthesis or metabolism of a vitamin.

Appetite - A desire for food or water; generally a long-term phenomenon, in contrast to short term satisfaction.

Ash - The mineral matter present in feed. It is measured by burning the sample at 500°C until all organic matter is burned and removed.

Available nutrient - A nutrient which can be digested, absorbed, and/or used in the body.

Balanced ration or diet - A mixture of feeds which provides the essential nutrients in the required proportions.

Beriberi - A nutritional disorder caused by thiamine (vitamin B1) deficiency.

Biological value - The efficiency with which a protein supplies the required amounts of essential amino acids; usually expressed as a percentage.

Biopsy - The removal and examination of tissue or other material from the living body.

Blending - The process of combining two or more feed ingredients.

Bloat - A disorder of ruminant animals which involves distention of the rumen with gas of fermentation.

Blocked, blocking - Having agglomerated individual ingredients or mixtures into a large mass.

Bolus - A solid mass of ingesta that, in ruminants, is regurgitated for remastication during rumination.

Bran - The tissue layers (pericarp or seed coat) removed during cereal grain processing. Generally low in energy value and starch content, bran is an essential by-product for animal feeding.

Buffer - Chemical compound that can lessen changes in pH when an acid or alkali is mixed with it. Buffers, such as sodium bicarbonate, are added to reduce the risk of rumen acidosis (low pH).

Butyric acid - A saturated fatty acid that is usually found in rumen contents and in poor-quality forages.

By-product - Secondary products created in addition to the main product.

Calcium - A silvery soft metallic chemical element that is essential for strong healthy bones. In its ionic form, it is required for many functions in the plant and animal world. It is most critically needed for nerve and muscle function, for constructing the skeleton, for cellular integrity and cell-to-cell adhesion, but is required in many other life processes.

Calf - The young of any species of Bovidae (cattle) and of certain other species, such as deer. The term is usually applied from birth until the onset of puberty. This will occur at around 1 year of age, depending on season in some species and on plane of nutrition in all species.

Calorie - A unit of measurement for energy. The heat required to increase the temperature of 1 g of water from 14.5° to 15.5°C.

Carbohydrates - The most abundant group of organic compounds in the world. Their abbreviation, CHO, indicates that they contain carbon, hydrogen and oxygen. Many different kinds are found in plant tissues; some are vital to animal metabolism. In terms of dairy cow diet, carbohydrates are the largest component, contributing 60%-70% of the net energy used for milk production.

Carcinogen - Any substance that can cause cancer.

Carrier - An edible material used to facilitate the addition of micronutrients to a ration.

Colostrum - Also known as “first milk.” The milk formed before and around the time of parturition. Colostrum is the major source of passive immunity for most domestic animals and is also a rich source of nutrients.

Complete feed - A single feed mixture used as the only source of food for an animal. A mixture of dietary ingredients designed to meet all the nutrient requirements of an animal.

Concentrate - A generic term to describe any non-forage dietary ingredient, usually for herbivores. Any feed containing relatively low fiber (20% or less) and with 60% or more TDN. Opposite of roughage; or a concentrated source of one or more nutrients used to supplement a feed mix. A concentrate may be low or rich in protein.

Crude fat - The portion of a feed (or other material) that is soluble in ether; also referred to as ether extract.

Crude fiber - The fibrous, less digestible portion of a feed.

Crude protein - Total ammoniacal nitrogen x 6.25, based on the fact that feed protein, on the average, contains 16% nitrogen; many nonprotein nitrogen compounds may be included.

Crumbles - (Physical form) Pelleted feed reduced to granular form.

Deamination - Removal of the amino group from an amino acid.

Debeaking - The act of removing a chicken or poult's beak with an electronic debeaker to avoid cannibalism. Also referred to as beak trimming.

Defluorinated - Having the fluorine content reduced to a level that is nontoxic under normal feed use.

Dehull, dehulling - The process of removing the outer layer (hulls or chaff) of a seed or a grain.

Dehydrated, dehydrating - The process of removing water or moisture by thermal means.

Desiccate - To dry out thoroughly.

Detoxification - Reducing the poisonous effect of a toxin, hence, changing it to a less toxic compound.

Diet - A regulated selection or combination of feed ingredients given on a constant or prescribed schedule.

Digesta - Contents of the digestive tract consisting of undigested feed mixed with secretions, desquamated mucosal cells and microorganisms.

Digestibility, apparent - The percentage of a feed or nutrient that is apparently absorbed from the GI tract as indicated by intake minus fecal output; it differs from true digestibility in that feces contain substances derived from the body, many microbial products, and various secretions, as well as undigested food.

Digestibility, true - The percentage of a feed nutrient actually absorbed from the GI tract.

Dilute - An edible substance used to mix with and reduce the concentration of nutrients and/or additives to make them more acceptable to animals, safer to use, and more capable of being mixed uniformly in a feed.

Diuretic - A substance that promotes the increased flow of urine.

Digestion - The process of breaking down large insoluble food molecules into a form that the body can absorb.

Drug - As defined by FDA as applied to feed, a substance (a) intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease in humans or other animals, or (b) a substance other than food intended to affect the structure or any function of the body of humans or other animals.

Dry matter - The part of a feed or tissue that remains after water is removed by drying in an oven.

Dry period - The period of time between lactation.

Edema - An abnormal accumulation of fluid in a part of or in the entire body.

Element - Any one of the chemical atoms of which all matter is composed.

Emaciated - Excessive leanness; a wasted condition of the body.

Electrolytes - Soluble ions in body fluids.

Emulsifier - A substance used to stabilize an emulsion, in animal feeding most commonly to make a liquid mixture of fat and water.

Endemic - A disease of low morbidity that persists over a long period of time in a certain region.

Ensilage - The same as silage.

Ensiled - Having been subjected to an anaerobic fermentation to form silage.

Enteritis - Inflammation of the intestines.

Enzyme - A protein formed in plant or animal cells which acts as an organic catalyst.

Evaporated, evaporating - (Process) Reduced to denser form; concentrated as by evaporation or distillation.

Eviscerated - Having had all organs in the great cavity of the body removed.

Excreta - The products of excretion, primarily feces and urine.

Exogenous - Originating from outside the body.

Expanded, expanding - (Process) Subjected to moisture, pressure, and temperature to gelatinize the starch portion. When extruded, its volume is increased due to abrupt reduction in pressure.

Extracted, mechanical - (Process) Having removed fat or oil from materials by heat and mechanical pressure. Similar terms are “expeller extracted,” “hydraulic extracted” and “old process.”

Extracted, solvent - (Process) Having removed fat or oil from materials by organic solvents. Similar term is “new process.”

Extruded - A process by which feed has been pressed, pushed, or protruded through orifices under pressure.

Fasting - To abstain from all food.

Fat soluble - Soluble in fats and fat solvents but generally not soluble in water.

Fattening - The deposition of excess energy in the form of adipose tissue (fat).

Feces - The excreta discharged from the digestive tract through the anus; composed of undigested food residues, microorganisms, and various materials originating in the liver and intestinal tract.

Feed - Any material used as food by an animal; same as feedstuff.

Feed additive concentrate - (Part) As defined by FDA, an article intended to be further diluted to produce a complete feed or a feed additive supplement and not suitable for offering as a supplement or for offering free choice without dilution. It contains, among other things, one or more additives in amounts in a suitable feed base such that from 10 to 100 lb of concentrate must be diluted to produce 1 ton of a complete feed. A feed additive concentrate is unsafe if fed free choice or as a supplement because of danger to the health of the animal or because of the production of residues in the edible products from food-producing animals in excess of the safe levels established.

Feed additive premix - As defined by FDA, an article that must be diluted for safe use in a feed additive concentrate, a feed additive supplement, or a complete feed. It contains, among other things, one or more additives in high concentration in a suitable feed base such that up to 100 lb must be diluted to produce 1 ton of complete feed. A feed additive premix contains additives at levels for which safety to the animal has not been demonstrated and/or that may result when fed undiluted in residues in the edible products from food-producing animals in excess of the safe levels established.

Feed additive supplement - As defined by FDA, an article for the diet of an animal that contains one or more food additives and is intended to be (a) further diluted and mixed to produce a complete feed; or (b) fed undiluted as a supplement to other feeds; or (c) offered free choice with other parts of the rations separately available. Note: A feed additive supplement is safe for the animal and will not produce unsafe residues in the edible products from food-producing animals if fed according to directions.

Feed grade - Suitable for animal food but not permitted by regulating agencies to be used in human foods.

Feedlot - An area of land on which animals are fed or finished for market.

Fiber - The cellulose part of forages which is low in TDN and hard to digest by monogastric animals.

Fibrous - High in content of cellulose and/or lignin (or in cell walls of NDF, neutral detergent fiber).

Finish - To fatten an animal in preparation for slaughtering for food; also, the degree of fatness of such an animal.

Fistula - An abnormal passage from some part of the body to another part or the exterior, sometimes surgically inserted.

Flora - The plant life of a given region or locality. In nutrition, it generally refers to the bacteria present in the digestive tract.

Flour - (Part) Soft, finely ground and bolted meal obtained from the milling of cereal grains, other seeds, or products. It consists essentially of the starch and gluten of the endosperm.

Flush - The practice of feeding females more generously approximately two weeks before breeding.

Fodder - The entire above ground part of nearly mature corn or sorghum in the fresh or cured form.

Forage - Crops used as pasture, hay, haylage, silage, or green chop for feeding animals.

Formula feed - Two or more ingredients proportioned, mixed, and processed according to specifications.

Fortify - To add one or more nutrients to a feed to increase its content to a needed level.

Founder - A condition of indigestion or overloaded stomach in the animals due to over eating. Or, may also be the crippled condition of an animal afflicted with laminitis.

Fresh - Usually denotes the green or wet form of a feed or forage.

Fructose - A six-carbon monosaccharide; one of the components of sucrose.

Full-feed - A term indicating that animals are being provided as much as they will consume safely without going off the feed.

Galactose - A six-carbon monosaccharide; one of the components of lactose.

Gall bladder - A membranous sac attached to the liver of farm livestock (except for the horse) in which bile is stored.

Gastric juice - A clear liquid secreted by the wall of the stomach; it contains HCI and the enzymes rennin, pepsin, and gastric lipase.

Gastritis - Inflammation of the stomach.

Gastrointestinal - Pertaining to the stomach and intestine.

Gelatinized, gelatinizing - (Process) Having had the starch granules completely ruptured by a combination of moisture, heat, and pressure, and, in some instances, by mechanical shear.

Germ - When used as a feed term, the embryo of a seed.

Glucogenesis - The formation of glucose by the breakdown of glycogen.

Gluconeogenesis - The formation of glucose and glycogen from non-glucose matter.

Glucose - A six-carbon monosaccharide found in the blood and as a component of sucrose and maltose and other sugars.

Gluten - The tough, viscid, nitrogenous substance remaining when the flour of wheat or other grain is washed to remove the starch.

Glycerol - An alcohol containing three carbons and three hydroxy groups; a component of a fat.

Glycogen - A polysaccharide found in the liver and muscles as a reserve form of quickly available energy.

Glycogenesis - The formation of glycogen.

Glycolysis - The decomposition of sugars and metabolism to lactic acid in animals or pyruvic acid in enzymatic reactions.

Goiter - An enlargement of the thyroid gland sometimes caused by an iodine deficiency.

Gossypol - A substance present in cottonseed (and meal) which is toxic to swine and some other non ruminant species.

Grain - (Part) Seed from cereal plants.

GRAS - Abbreviation for the phrase “generally recognized as safe.” A substance that is generally recognized as safe by experts qualified to evaluate the safety of the substance for its intended use.

Gravid - Pregnant.

Green chop - Forage harvested and fed in the green, chopped form.

Grits - (Part) Coarsely ground grain from which the bran and germ have been removed, usually screened to uniform particle size.

Groat - Grain from which the hull has been removed.

Gross energy - The total heat of combustion of material burned in a bomb calorimeter.

Ground, grinding - (Process) Reduced in particle size by impact, shearing, or attrition.

Growth - An increase in muscle, bone, vital organs, and connective tissue as contrasted to an increase in adipose tissue (fat deposition).

Gruel - A feed prepared by mixing ground ingredients with hot or cold water.

Hay - Dried forage (grasses, alfalfa, clovers) used for feeding farm animals.

Heat increment - The heat that is unavoidably produced by an animal incidental with nutrient digestion and utilization.

Heat labile - Unstable to heat.

Heat processed, heat processing - (Process) Subjected to a method or preparation involving the use of elevated temperatures with or without pressure.

Hematocrit - The volume of whole blood made up by the red blood cells after centrifugation.

Hemoglobin - The oxygen-carrying red protein of the red corpuscles.

Hemorrhage - Copious loss of blood through bleeding.

Hepatitis - Inflammation of the liver.

High-moisture silage - Silage usually containing 70 percent or more moisture.

Homogenized - A process in which particles are broken down into evenly distributed globules small enough to remain emulsified for a long period of time.

Hormone - A chemical secreted in the body fluids by an endocrine gland that has a specific effect on other tissues.

Hulls - (Process) Outer covering of grain or other seed.

Hunger - The desire for food; the antithesis of satiety.

Hydrogenation - The chemical addition of hydrogen to any unsaturated compound (double bond), often to fatty acids.

Hydrolysis - The chemical process whereby a compound is split into simpler units with the uptake of water.

Hygroscopicity - The tendency for a substance to absorb or attract moisture from the air.

Hyperthyroidism - A condition due to excessive functional activity of the thyroid gland and characterized by increased basal metabolism.

Hypervitaminosis - An abnormal condition resulting from the intake of (or treatment with) an excess of one or more vitamins.

Hypocalcemia - A below normal concentration of calcium in blood.

Hypoglycemia - A below normal concentration of blood glucose.

Ileum - The third section of the small intestine.

Implant - A substance that is inserted into the body tissue for the purpose of growth promotion or controlling some physical function.

Inert - Relatively inactive.

Ingest - To eat or take in through the mouth.

Ingredient, feed ingredient - A component part or constituent of any combination or mixture making up a commercial feed.

Ingesta - Food and drink taken into the stomach.

Inorganic - Pertaining to compounds not containing carbon.

Insulin - A hormone secreted by the pancreas into the blood; it is involved in regulation and utilization of blood glucose.

International chick unit (ICU) - The unit used to express vitamin D for poultry.

International unit (IU) - A standard unit of potency of a biological unit as defined by the International Conference for Unification of Formulae.

Intestinal tract - The small and large intestines.

Intrinsic factor - A chemical substance in the normal stomach necessary for absorption of vitamin B₁₂.

Inulin - A polysaccharide found in some root crops. Composed of fructose.

In vitro - “In a glass.” Occurring in an artificial environment, as in a test tube.

In vivo - Occurring in the living body.

Iodine number - The amount of iodine (in grams) that can be taken up by 100 g of a fat or fatty acid; it is a measure of unsaturation.

Jejunum - The middle portion of the small intestine.

Joule - A unit of work or energy, as well as the concept of heat (4.184j = 1 calorie).

kcal - An abbreviation for kilocalorie; 1000 calories.

Keratin - An S-containing protein found in tissues such as hair, wool, feathers, horn, and hooves.

Keto acids - Acids that are the critical intermediates in the metabolism and interconversion of amino acids.

Ketone - A group of chemicals which includes acetone, acetoacetic acid, and betahydroxy butyric acid; they are produced in excess when carbohydrate metabolism is low and fat is being metabolized for energy.

Ketosis - A condition characterized by an elevated concentration of ketone bodies in body tissues and fluids.

Kibbled, kibbling - (Process) Cracked or crushed baked dough or extruded feed that has been cooked prior to or during the extrusion process.

Kwashiorkor - A nutritional disorder of children caused by a severe protein deficiency, which is characterized by changes in pigmentation of skin and hair, edema, skin lesions, anemia, and apathy.

Labile - Unstable; easily destroyed.

Lactase - An enzyme present in the intestinal juice that acts on lactose to produce glucose and galactose.

Lactic acid - An organic acid commonly found in sour milk and silage and one that is important in the body during anaerobic glycolysis.

Laminitis - An inflammation of the sensitive laminae under the horny wall of the hoof; often associated with overfeeding.

Laxative - A medicine of agent that can induce bowel movement and relieve constipation.

Lesion - An unhealthy change in the structure of a part of the body.

Legume - A plant member of the leguminosae family (alfalfa, clovers, etc.), with the character of forming N-fixing nodules on its roots.

Lignin - A biologically unavailable polymer that is a major structural component of the cell walls of plants.

Limited feeding - A feeding system in which animals are fed less than their voluntary intake.

Limiting amino acid - The indispensable amino acid of a protein which shows the greatest percentage deficit.

Linoleic acid - An 18-carbon unsaturated fatty acid; one of the essential fatty acids; it occurs widely in plant glycerides.

Lipase - A fat-splitting enzyme; different lipases are produced by the stomach and the pancreas.

Lipids - Substances that are diverse in chemical nature but are soluble in fat solvents.

Lipolysis - The decomposition or splitting up of fat to yield glycerol and fatty acids.

Lymph - The slightly yellow, transparent fluid occupying the lymphatic channels of the body.

Maize - Also called corn or Indian corn, is probably the most important cereal plant of the Gramineae (grass) family.

Malignant - Virulent or destructive as applied to cancer.

Malnutrition - An overall term for poor nourishment.

Malt - Sprouted and steamed whole grain from which the radicle has been removed.

Maltase - An enzyme that splits maltose to produce two molecules of glucose.

Manure - The refuse from animal quarters consisting of excreta with or without litter or bedding.

Mash - (Physical form) A mixture of ingredients in meal form. Similar term is mash feed.

Mastication - A process of chewing feed in preparation for swallowing.

Mastitis - An inflammation of the mammary gland.

Meal - (Physical form) An ingredient that has been ground or otherwise reduced in particle size.

Meconium - A dark green excrement material accumulated in the intestines during the fetal development.

Medicated feed - Any feed that contains drug ingredients intended or represented for the cure, mitigation, treatment, or prevention of diseases of animals other than humans or that contains drug ingredients intended to affect the structure or function of the body of animals other than humans.

Megacalorie (Mcal) - 1000 kcal or 1 million calories; synonymous with therm.

Metabolic size - The body weight raised to the 3/4 power (W0.75); a means of relating body weight to heat production of an animal.

Metabolism - The sum of all the physical and chemical processes taking place in a living organism.

Metabolite - Any compound produced during metabolism.

Methane - A major product of anaerobic fermentation of carbohydrates; found in the rumen.

Microbes - The same as microorganisms.

Microingredient - Any ration component normally measured in milligrams of micrograms per kilogram or in parts per million (ppm).

Microorganism - A minute living organism, usually microscopic, such as bacteria and protozoa.

Mill by-product - (Part) A secondary product obtained in addition to the principal product in milling practice.

Mill dust - (Part) Fine feed particles of undetermined origin resulting from handling and processing feed and feed ingredients.

Mill run - (Part) The state in which a material comes from the mill, ungraded and usually uninspected.

Mineralize, mineralized - (Process) To supply, impregnate, or add inorganic mineral compounds to a feed ingredient or mixture.

Minerals - As applied to animal nutrition, elements that are essential to the plant or animal and that are found in its tissues.

Miscible - Capable of being mixed easily with another substance.

Mixing - (Process) To combine by agitation two or more materials to a specific degree of dispersion.

Molasses - The thick, viscous by-product resulting from refined sugar production, or the concentrated partially dehydrated juices from fruits.

Monogastric - The simple stomach; often used for nonruminant animals, but technically a misnomer because ruminants have only one stomach with four compartments.

Monosaccharide - Anyone of several simple sugars.

Morbidity - A state of sickness.

Mycotoxin - A fungal toxin; quite often present in feeds, sometimes at lethal levels.

National Research Council (NRC) - A division of the National Academy of Sciences established in 1916 to promote the effective utilization of scientific and technical resources.

NDF - Neutral detergent fiber, the fraction containing mostly cell wall constituents of low biological availability.

Necrosis - Death of a part of the cells making up a living tissue.

Nephritis - Inflammation of the kidneys.

Net energy (NE) - Metabolizable energy minus the heat increment.

Neuritis - Inflammation of the peripheral nerves.

NFE (nitrogen-free extract) - Consists primarily of readily available carbohydrates such as sugars and starches; part of the proximate analysis.

Nitrogen balance - A nutritional state in the animal determined from the N intake minus the N in feces and urine.

Nonprotein nitrogen (NPN) - Anyone of a group of N-containing compounds that are not true proteins that can be precipitated from a solution; ammonia and urea are examples.

Nonruminant - A simple-stomached animal that does not ruminate.

Nutrient - Any chemical substance that provides nourishment to the body.

Nutrient balance - The difference between the supply (intake + endogenous production) of a nutrient and its loss from the body.

Nutrient deficiency - The supply of a nutrient at a rate below an animal’s requirement, leading to clinical symptoms of deficiency.

Nutrient requirement - The amount of a nutrient needed for a specified purpose which, in farm animals, may be maximum weight gain, milk yield, etc.

Nutritional disorder - Any malfunction of the body caused by deficiency or excess of one or more nutrients, or imbalance between nutrients.

Nutritive value - A non-specific term for the value of the feed as a source of energy or specific nutrients for a class of livestock.

Oats - Several members of the Gramineae (grass) family. The best known are Avena sativa, A. sterilis and A. strigosa. Generally ‘oats’ refers to A. sativa, which has long been established as a feed for ruminants and horses.

Obesity - The accumulation of body fat beyond the amount needed for good health.

Offal - Material left as a by-product from the preparation of some specific product, less valuable portions, and the by-products of milk.

Oil - Usually a mixture of pure fats which is liquid at room temperature.

Oleic acid - An 18-carbon fatty acid that contains one double bond; it is found in animal and vegetable fat.

Omasum - The third compartment of the ruminant stomach.

Orts - Fragments of feed that an animal refuses to eat.

Ossification - The process of deposition of bone salts in the cartilage of the bones.

Osteitis - Inflammation of a bone.

Osteomalacia - A weakening of the bones caused by inadequate Calcium, Phosphorus, and/or vitamin D or by some diseases.

Osteoporosis - A reduction in the normal amount of bone salts (often occurring with age) such that the bone becomes porous and brittle.

Oxidation - The union of a substance with oxygen; the increase of positive charges on an atom or loss of negative charges.

Paddock - A small fenced field used for grazing purposes.

Palatability - The relative attractiveness of feed to the animal.

Palmitic acid - A saturated fatty acid with 16 carbon atoms.

Pancreas - An organ located near the stomach; it produces pancreatic juice, which is secreted into the small intestine via the pancreatic duct. It is also an endocrine gland that secretes insulin and glucagon, hormones that control metabolism of glucose.

Pathogen - Any disease-producing microorganism or material.

Pearled, pearling - (Process) Dehulled grains reduced by machine brushing into smaller smooth particles.

Pelleting - The process of forming feed into pellets.

Pellets - (Physical form) Agglomerated feed formed by compacting and forcing through die openings by a mechanical process. Similar terms are pelleted feed and hard pellet.

Pellet, soft - (Physical form) Pellets containing sufficient liquid to require immediate dusting and cooling. Similar term is high-molasses pellets.

Pentosan - A polysaccharide made up primarily of five-carbon sugars; araban and xylan are examples.

Pentose - A five-carbon sugar such as arabinose, xylose, or ribose.

Pepsin - A proteolytic enzyme produced by the stomach.

Permeable - Capable of being penetrated.

Physiological - Pertaining to the science that deals with the functions of living organisms or their parts.

Pica - A depraved appetite characterized by a craving for unnatural articles of food (dirt, sand, feces, etc.).

Plasma - The fluid portion of the blood; serum is plasma from which the fibrinogen has been removed by the clotting process.

Polyneuritis - An inflammation encompassing many peripheral nerves.

Polyuria - An excessive excretion of urine.

Precursor - A compound that can be used by the body to form another compound, such as carotene used to produce vitamin A.

Premix - A uniform mixture of one or more micro ingredients and a carrier, used in the introduction of micro ingredients into a larger batch.

Premixing - (Process) The preliminary mixing of ingredients with diluents and/or carriers.

Product - (Part) A substance produced from one or more other substances as a result of chemical or physical change.

Propionic acid - One of the volatile fatty acids commonly found in rumen contents.

Protein - Any of many complex organic compounds formed from various combinations of amino acids and, sometimes, other non protein components.

Protein equivalent - A term indicating the total N contribution of a substance in comparison with the N content of protein (e.g. urea - 45% N x 6.25 = 281%).

Provitamin - A precursor of vitamin.

Proximate analysis - A combination of analytical procedures used to describe feeds, excreta, and other agricultural products.

Purified diet - A mixture of the known essential dietary nutrients in a pure form that is fed to experimental animals in nutrition studies.

Putrefaction - The decomposition of proteins by microorganisms under anaerobic conditions.

Pyrexia - A feverish condition.

Q

Radioactive - An element that emits particles during the disintegration of the nuclei; the emissions include alpha and beta particles and gamma rays.

Radioisotope - A radioactive form of an element; often used in experimental work with plants and animals to trace metabolic activity in the animal.

Rancid - A term used to describe fats that have undergone partial decomposition; rancid fats may have objectional tastes or odors and may be toxic.

Range cubes - (Physical form) Large pellets designed to be fed on the ground. Similar to range wafer.

Ration - A fixed portion of feed, usually expressed as the amount of a diet allowed daily.

Relative feed value (RFV) - Developed primarily for use with legume or legume/grass forages, RFV combines digestibility and intake estimates into one number for an easy and effective way to identify and market quality hay.

Rennin - A milk-curdling enzyme present in the gastric juice of young mammals.

Resorption - A return of the nutritive compounds of a partially developed fetus and fetal membranes to the system of the mother.

Reticular groove - A muscular structure at the lower end of the esophagus that, when closed, forms a tube allowing milk to go directly into the abomasum; sometimes called the esophageal groove.

Reticulum - The first compartment of the ruminant stomach.

Rolled, rolling - (Process) Having changed the shape and/or size of particles by compressing between rollers. It may entail tempering or conditioning.

Roughage - Consists of pasture, silage, hay, or other dry fodder. It may be of high or low quality. Roughages are usually high in crude fiber (more than 18 percent) and relatively low in NFE (approximately 40 percent).

Rumen - The second compartment of the ruminant stomach.

Rumen degradable protein (RDP) - Known previously as degradable intake protein (DIP), protein or nitrogen that is degraded in the rumen by microorganisms and incorporated into microbial protein or freed as ammonia.

Ruminant - Any of a group of hooved mammals that have a four-compartmented stomach and that chew a cud while ruminating.

Rumination - The process of regurgitating previously eaten feed, re-swallowing the liquids, and re-chewing the solids (cud).

Salmonella - A pathogenic, diarrhea-producing organism sometimes present in contaminated feeds.

Sarcoma - A tumor of fleshy consistency, often highly malignant.

Satiety - The condition of being fully satisfied with food; the opposite of hunger.

Saturated fat - A fat that contains no fatty acids with double bonds.

Scalped, scalping - (Process) Having removed larger material by screening.

Scratch - (Physical form) Whole, cracked, or coarsely cut grain. Similar terms are scratch grain, scratch feed.

Screened, screening - (Process) Having separated various-sized particles by passing them over and/or through screens.

Self-fed - Provided with part or all of the ration on a continuous basis so that the animal may eat at will.

Separating - (Process) Classification of particle size, shape, and/or density.

Separating, magnetic - (Process) Removing ferrous materials by magnetic attraction.

Serum - The colorless fluid portion of blood remaining after clotting and removal of corpuscles. Differs from plasma in that fibrinogen has been removed.

Shorts - The particle of bran, germ, flour or offal from the tail of the mill from commercial flour milling.

Shrinkage - A term used to indicate the body weight loss due to stressful conditions such as being transported, severe weather, or feed shortage.

Silage - Feed resulting from the storage and fermentation of wet crops under anaerobic conditions.

Slotted floor - Floors in an animal pen with slots through which the feces and urine pass to a storage area below or nearby.

Solubles - Liquid containing dissolved substances obtained from processing animals or plant materials. May contain some fine suspended solids.

Solvent extracted - A process for the extraction of oil from seeds involving the use of an organic solvent.

Specific heat - The heat absorbing capacity of a substance in relation to that of water.

Stabilized - Made more resistant to chemical change by the addition of a particular substance.

Starch - A polysaccharide that yields glucose on hydrolysis; found in high concentrations in most seed grains.

Steamed, steaming - (Process) Having treated ingredients with steam to alter physical and/or chemical properties. Similar terms are steam cooked, steam rendered, tanked.

Stearic acid - An 18-carbon saturated fatty acid.

Sterol - An alcohol of high molecular weight, such as cholesterol; a basic compound used to synthesize many vital chemicals for both plants and animals.

Stocker cattle - Usually, young cattle that are light and thin, and lack finish.

Stocking rate - A pasture management term pertaining to animal numbers in relation to carrying capacity of a unit or area of the pasture.

Stomach - The part of the digestive tract in which chemical digestion is initiated in most animal species. It normally lies between the esophagus and the small intestine.

Stover - The mature, curled stalks and leaves of corn after the ears, or sorghum after the heads have been harvested.

Stress - Any circumstance that tends to disrupt the normal, steady functioning of the body and its parts.

Sucrose - A disaccharide (common table sugar) composed of one molecule each of glucose and fructose.

Supplement - A feed used with another to improve the nutritive balance or performance of the total and intended to be (a) fed undiluted as a supplement to other feeds, (b) offered free choice with other parts of the ration separately available, or (c) further diluted and mixed to produce a complete feed.

Syndrome - A medical term meaning a set of symptoms that occur together.

Taste - The ability to distinguish flavors between or among solid or liquid components of the diet.

TDN (total digestible nutrients) - A value that indicates the relative energy value of a feed for an animal.

Tetany - A condition in animals in which there are localized, spasmodic, muscular contractions.

Thyroxine - An iodine-containing hormone that is produced by the thyroid gland.

TMR (total mixed ration) - A blend of all feedstuffs (forages and grains) in one feed. A complete ration fits well into mechanized feeding and the use of computers to formulate least-cost rations.

Toasted - (Process) Browned, dried, or parched by exposure to a fire or to gas or electric heat.

Trace minerals - Mineral nutrients required by animals in micro amounts only (measured in milligrams per pound or smaller amounts).

Triglyceride (fat) - An ester composed of glycerol and three fatty acids.

True protein - A precipitable protein rather than any of several non-protein compounds.

Trypsin - A proteolytic digestive enzyme produced by the pancreas.

Underfeeding - A term referring to not providing the animal sufficient dietary energy.

Unsaturated fat - A fat containing from one to three fatty acids that contain one or more double bonds.

Unthriftness - Lack of vigor, poor growth or development.

Urea - The chief end product of protein metabolism in mammals; one of the main nitrogenous constituents in urine; a synthetic product sometimes used as a nitrogen source in rations for ruminants.

Urease - An enzyme that acts on urea to produce carbon dioxide and ammonia; it is present in numerous microorganisms in the rumen.

Uremia - A toxic accumulation of urinary constituents in the blood because of faulty kidney excretion.

Uric acid - A nitrogenous end product of purine metabolism; it is the principal N-containing component in urine of birds.

Urine - A pale yellow fluid derived from blood filtered by the kidney.

USP (United States Pharmacopoeia) - A unit of measure or potency of biologicals which usually coincides with an international unit (IU).

Veal - A calf fed for early slaughter.

VFA - Volatile fatty acids.

Villi - Small threadlike projections attached to the interior of the wall of the small intestine to increase its absorptive surface area.

Viscera - The organs of the great cavities of the body, which are removed at slaughter.

Viscosity - The freedom of flow of liquids.

Vitamin - One of a group of organic substances that are essential in small amounts for the lives of animals.

Vitamins, fat soluble - Vitamins soluble in fats. This group includes vitamins A, D₂, D₃, E (tocopherol), and K.

Vitamins, water soluble - Vitamins soluble in water. This group includes ascorbic acid (vitamin C) and the B complex: biotin, choline, cobalamin or cyanocobalamin, folacin, niacin, pantothenic acid, pyridoxine, riboflavin, and thiamin.

Voluntary food intake - The food intake of animals allowed continuous unrestricted access to feed (ad libitum feeding). It is usually expressed as the weight of food eaten per 24 h.

Wafer - (Physical form) A form of agglomerated feed based on fibrous ingredients in which the finished form usually has a diameter or cross section measurement greater than its length.

Wafered, wafering - (Process) Having agglomerated a feed of a fibrous nature by compressing into a form usually having a diameter or cross section measurement greater than its length.

Weaning - The stopping of young animals from nursing or suckling their mothers.

Weanling - A recently weaned animal.

Wet-milled - A process in which feed material is steeped in water with or without sulphur dioxide to soften the kernel in order to facilitate the separation of various component parts.

Wet rendered - A process in which material is cooked with steam under pressure in closed tanks.

Whey - The watery part of milk separated from the curd.

Wort - The liquid portion of malted grain. A solution of malt sugar and other soluble extracts from malted mash.

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Yearling - Refers to a male or a female farm animal (especially, cattle and horses) during the first year of its life.

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