ANFS251 Exam 1

University of Delaware, Spring 2026

Feedstuffs

Plant- or animal-derived materials used to supply nutrients to animals.

Nutrients

Chemical components of feed that support growth, maintenance, reproduction, and health.

Diet Formulation

The process of combining feed ingredients to meet the nutritional needs of animals.

Cereal Grains

Plants such as corn, wheat, oats, barley, and rye that store energy primarily as starch in their seeds.

Legumes

Plants capable of fixing atmospheric nitrogen through symbiosis with soil bacteria; used as protein sources.

Forage Legumes

Legumes such as alfalfa and clover grown in pastures and used as roughage.

Oilseed Legumes

Legumes such as soybeans that produce beans used for oil and high-protein meals.

Grasses

Forage plants such as timothy, ryegrass, and fescue commonly used in pastures.

Forage

Plant material, usually high in fiber, consumed primarily by grazing animals.

Roughage

High-fiber feedstuffs containing cellulose and hemicellulose.

Pasture

A managed or natural area where animals graze on grasses and legumes.

Natural Pasture

Uncultivated grazing land containing native grasses, forbs, and shrubs.

Managed Pasture

Land seeded and managed by livestock producers to optimize forage production.

Hay

Forage crops that are cut, dried, and baled for later feeding.

Silage

Preserved forage stored under anaerobic conditions and fermented by microorganisms.

Silo

A storage structure used to preserve forage as silage.

Corn Silage

Silage made from the entire corn plant, commonly used in ruminant diets.

Haylage

Silage made from partially dried forage crops.

Forbs

Broad-leaved herbaceous plants found in pastures that are not grasses or legumes.

Shrubs

Woody plants that may be part of native pastures.

Cellulose

A structural carbohydrate in plant cell walls that is poorly digested by non-ruminants.

Hemicellulose

A plant fiber component associated with cellulose in cell walls.

Ruminants

Animals with a rumen capable of microbial fermentation of fibrous feeds.

Non-ruminant Herbivores

Animals that consume forage but lack a rumen.

Monogastric Animals

Animals with a single-chambered stomach requiring highly digestible feeds.

Starch

A carbohydrate stored in plant seeds that provides energy.

Seed Head

The flowering and seed-bearing part of cereal grain plants.

Kernel

The edible seed of cereal grains such as corn.

Straw

The dried stems of cereal grains left after seed harvest, used mainly for bedding.

Oilseed Meal

The protein-rich material remaining after oil extraction from oilseeds.

Soybean Meal

A high-protein feed ingredient produced from soybeans after oil extraction.

Crude Protein

An estimate of protein content in feed based on nitrogen concentration.

Symbiotic Nitrogen Fixation

The process by which legumes and bacteria convert atmospheric nitrogen into usable forms.

Palatablity

The taste and acceptability of feed to animals.

Digestibility

The extent to which nutrients in feed can be broken down and absorbed.

Endophyte

A fungus living within certain grasses, such as tall fescue, that may produce toxins.

Tall Fescue Toxicosis

A condition caused by toxins from endophyte-infected tall fescue.

Pasture Mix

A blend of grass and legume seeds selected for grazing systems.

Gastrointestinal (GI) Tract

The organ system responsible for digestion, absorption of nutrients, and elimination of waste.

Digestion

The process of converting complex nutrients in feed into simpler forms that can be absorbed by the animal.

Absorption

The movement of digested nutrients across the lining of the GI tract into the bloodstream.

Passive Absorption

Movement of nutrients from an area of higher concentration to lower concentration without energy input.

Active Absorption

Transport of nutrients across cell membranes using energy, often against a concentration gradient.

Herbivore

An animal that consumes primarily plant material.

Carnivore

An animal that consumes primarily other animals.

Omnivore

An animal that consumes both plant and animal materials.

Rumen

The primary fermentation chamber in ruminant animals where microbial digestion occurs.

Gut Morphology

The shape, size, and structure of the gastrointestinal tract.

Sacculation

The presence of pouch-like enlargements in sections of the digestive tract indicating fermentation activity.

Peristalsis

Wave-like muscular contractions that move feed through the digestive tract.

Rumination

The process by which ruminants regurgitate and rechew feed to improve fiber digestion.

Bolus

A mass of chewed feed mixed with saliva that is swallowed.

Saliva

A digestive secretion that lubricates feed, aids swallowing, buffers pH, and may contain enzymes.

Esophagus

A muscular tube that transports the bolus from the mouth to the stomach.

Stomach

A digestive organ that secretes acids and enzymes to begin chemical digestion.

Non-glandular Region

The portion of the stomach that does not secrete digestive enzymes or acids.

Cardiac Region

The stomach region that secretes mucus to protect stomach tissues.

Fundic Region

The stomach region that secretes hydrochloric acid, pepsinogen, and mucus.

Pyloric Region

The stomach region that secretes mucus and digestive enzymes and regulates digesta flow.

Mucin

A mucus substance that protects the stomach lining from digestion.

Hydrochloric Acid (HCl)

A stomach acid that lowers pH and activates digestive enzymes.

Pensinogen

The inactive precursor of pepsin secreted by the stomach.

Pepsin

An enzyme that digests proteins in the stomach.

Chyme

The semi-liquid, acidic mixture of partially digested feed leaving the stomach.

Small Intestine

The primary site of enzymatic digestion and nutrient absorption.

Duodenum

The first section of the small intestine where bile and pancreatic enzymes enter.

Jejunum

The middle section of the small intestine where most nutrient absorption occurs.

Ileum

The final section of the small intestine involved in nutrient absorption.

Bile

A digestive secretion that neutralizes stomach acid and emulsifies fats.

Pancreatic Enzymes

Enzymes that digest proteins, carbohydrates, and fats in the small intestine.

Villi

Finger-like projections lining the small intestine that increase surface area for absorption.

Large Intestine

The GI tract section involved in microbial fermentation, water absorption, and waste formation.

Rectum

The terminal section of the GI tract where feces are stored before excretion.

Microbial Fermentation

Digestion of feed by microorganisms producing organic acids and other compounds.

Volatile Fatty Acids (VFAs)

Organic acids produced by microbial fermentation used as energy sources.

Coprophagy

The consumption of feces to recover nutrients produced by microbial fermentation.

Water-Soluble Vitamins

Vitamins synthesized by gut microbes that may be absorbed by some animals.

Detoxification

The process by which harmful compounds are neutralized, primarily by the liver.

Pre-gastric Fermentation

Microbial fermentation occurring before the small intestine.

Post-gastric Fermentation

Microbial fermentation occurring after the small intestine.

Crop

A temporary storage organ in birds where ingested feed is held and softened before digestion.

Proventriculus

The glandular stomach of birds that secretes gastric juices such as hydrochloric acid, pepsinogen, and mucus

Gizzard (Ventriculus)

A muscular organ in birds that mechanically grinds feed, often with the aid of grit or small stones.

Grit

Small stones consumed by birds that aid the gizzard in grinding feed.

Ceca (Cecum)

Paired pouches in birds and a single pouch in mammals that serve as sites of microbial fermentation.

Urinary-Fecal Excretion

The combined elimination of urine and feces in birds due to a shared excretory pathway.

Rumen (Structure)

The entire four-compartment stomach system of ruminant animals.

Reticulum

The first compartment of the ruminant stomach with a honeycomb lining where fermentation begins.

Rumen (Compartment)

The largest fermentation chamber of the ruminant stomach where extensive microbial digestion occurs.

Reticulorumen / Ruminoreticulum

The combined reticulum and rumen, functioning together in fermentation and mixing of feed.

Omasum

The third compartment of the ruminant stomach with leaf-like folds that filter feed particles.

Abomasum

The true, glandular stomach of ruminants that secretes acids and enzymes similar to monogastric animals.

Papillae

Finger-like projections lining the rumen that increase surface area for absorption of fermentation products.

Regurgitation

The movement of partially digested feed from the rumen back to the mouth for further chewing.

Eructation

The process of expelling fermentation gases from the rumen, commonly known as belching.

Methane (CH4)

A gaseous byproduct of rumen microbial fermentation released during eructation.

Carbon Dioxide (CO2)

A primary gas produced during microbial fermentation in the rumen.

Bloat

A condition in ruminants caused by the inability to expel fermentation gases.

Esophageal/Reticular Groove

A muscular structure in young ruminants that directs milk past the rumen.

Milk Bypass

The passage of milk directly to the abomasum in young ruminants, avoiding fermentation.