Equine Diet & Lifestyle – Key Vocabulary

A comprehensive set of vocabulary flashcards covering the fundamental terms and concepts from the Equine Diet & Lifestyle lecture.

Natural diet

The continual intake of low-nutrient, varied forage that free-roaming horses evolved to eat while traveling long distances each day.

Domestication diet

A restricted, often grain-rich ration of limited forage types fed to housed horses, typically unlike what they would select in the wild.

Feral horse travel distance

The 15–20 miles per day that wild horses typically walk while seeking forage and water.

Equine stomach capacity

Approximately 2–4 gallons; begins emptying when only two-thirds full, favoring small frequent meals.

Free-choice forage

Unlimited access to hay/grass that keeps feed in the stomach, buffers acid, and lessens ulcer risk.

Small intestine (length)

About 70 feet long; site of most protein, starch, fat, calcium, and fat-soluble vitamin absorption.

Cecum

An 8-gallon microbial fermentation vat where fiber and leftover starch are digested over ~7 hours.

Volatile Fatty Acids (VFA)

Energy-rich acids produced from fiber fermentation; supply up to 70 % of a horse’s maintenance energy.

Limiting amino acid

An essential amino acid present in too small a quantity to permit full protein synthesis.

Lysine

The only equine essential amino acid with a defined requirement; often low in grass hay.

Methionine

Sulfur-containing amino acid important for hoof horn growth and structural integrity.

Simple carbohydrates

Sugars and starches rapidly digested in the small intestine and capable of spiking glucose/insulin.

Water Soluble Carbohydrates (WSC)

Sugars plus fructans extractable in water; part of the NSC value.

Ethanol Soluble Carbohydrates (ESC)

Sugar fraction that, together with starch, directly raises blood glucose and insulin.

Non-Structural Carbohydrates (NSC)

WSC plus starch; key number to monitor (<10 %) for laminitis-prone horses.

Complex carbohydrates

Structural fibers fermented in the hindgut to produce VFAs for steady energy without insulin spikes.

Fat digestion

Begins in the stomach but mainly occurs in the small intestine via bile secreted from the liver.

Fat-soluble vitamins

Vitamins A, D, E, K that require dietary fat for absorption and can be stored in the liver.

Major minerals

Minerals needed in larger amounts: calcium, phosphorus, magnesium, potassium, sodium, chloride, sulfur.

Trace minerals

Minerals required in small quantities, e.g., iron, zinc, copper, manganese, cobalt, iodine, selenium.

Calcium (function)

Muscle contraction, blood clotting, enzyme regulation, and bone/teeth formation.

Phosphorus (function)

Bone formation and metabolic partner to calcium; energy transfer (ATP).

Magnesium (function)

Bone structure and muscle relaxation; interacts with calcium in nerve impulses.

Potassium (function)

Primary intracellular cation that maintains acid-base balance and osmotic pressure.

Sodium (function)

Main extracellular cation critical for nerve function, fluid balance, and acid-base regulation.

Zinc (function)

Supports protein metabolism, immunity, vitamin A use, and formation of collagen and hoof keratin.

Copper (function)

Needed for elastic tissue synthesis, iron mobilization, melanin production, and strong hoof horn.

Manganese (function)

Essential for carbohydrate/fat metabolism and formation of cartilage via chondroitin sulfate.

Cobalt (function)

Required for microbial synthesis of vitamin B-12 in the large intestine.

Iodine (function)

Component of thyroid hormones that regulate basal metabolic rate.

Selenium (function)

Antioxidant element that also influences thyroid hormone metabolism; narrow safety margin.

Vitamin A

Fat-soluble vitamin rarely deficient; abundant in green forage and needed for vision and immunity.

Vitamin E

Antioxidant vitamin often supplemented when horses eat only dried hay lacking fresh pasture.

NRC guidelines

The National Research Council’s minimum nutrient requirements for horses, published 2007.

Hoof health

Overall integrity of the hoof, strongly influenced by diet balance, movement, and environment.

Insulin Resistance (IR)

Metabolic state where tissues respond poorly to insulin, leading to high insulin levels and laminitis risk.

Classic signs of IR

Cresty neck, fat pads at tail head, filled supra-orbital hollows, often with laminitis or obesity.

Cushing’s / PPID

Pituitary Pars Intermedia Dysfunction; endocrine disease causing muscle loss, long coat, laminitis, etc.

Biotin

Water-soluble B vitamin; 10–30 mg/day for 6–9 months may improve weak hoof horn.

Hay testing

Laboratory analysis of forage to determine energy, sugar, protein, and mineral content for diet balance.

Beet pulp

Low-starch, soluble-fiber feed soaked before use; provides calories and a carrier for supplements.

Grazing muzzle

Device placed on horses to limit grass intake and reduce sugar overload while still allowing movement.

Omega-3 fatty acids

Anti-inflammatory fats abundant in fresh grass and flax; ratio to omega-6 is ~4:1 in natural diets.

Omega-6 fatty acids

Pro-inflammatory fats high in oils like corn or rice bran; typically oversupplied relative to omega-3.

Salt requirement

Minimum of about 2 oz (3 Tbsp) daily; often unmet by blocks and should be fed loose if necessary.

Electrolytes

Mixtures of sodium, chloride, potassium, etc.; only needed in addition to salt during heavy sweat losses.

Feed label – ppm

Unit meaning parts per million; equals milligrams per kilogram and used for trace mineral amounts.

Forage analysis

Report showing digestible energy, sugars, protein, and mineral levels in hay or pasture samples.

Paddock Paradise

Track-based turnout design that encourages natural movement patterns and improves hoof stimulation.

Sub-clinical laminitis

Early hoof inflammation showing subtle signs like shortened stride or reluctance to turn, before overt lameness.

Enteroliths

Mineral stones that can form in the gut of horses on high-alfalfa diets, especially in California.

High-sugar risk times

Cool nights followed by sunny days, early spring/fall, or stressed grass when plant sugars accumulate.

NSC limit for laminitic horses

Total sugar plus starch in forage or feed kept below 10 % to prevent glucose/insulin spikes.

Hay feeding rate

General guideline of 1.5–2 % of body weight per day (15–20 lb for a 1,000 lb horse).

Track system

Narrow loop or pathway around a pasture used to stimulate movement, as in Paddock Paradise designs.

Blood builders

Supplements high in iron marketed to boost energy; generally unnecessary and may worsen mineral imbalances.

Safe starch intake

Controlled level of rapidly digestible carbohydrates to avoid colic, laminitis, and insulin surges.

High iron issues

Excess dietary or water iron that can hinder copper and zinc absorption and weaken hoof walls.

4 : 1 zinc-to-copper ratio

Recommended balance (approx.) to optimize absorption and support skin, hair, and hoof integrity.