A to Z of nutrition

A is for . . .

Ad Lib: Constant access to feed – for example, hay made available at all times.

Alfalfa: A nutritious legume (pod) plant, also called lucerne. It is farmed in the same way as hay, but in the UK it is dried at high temperatures.

Amino acids: Required for growth, repair and maintenance of body tissue. They are building blocks of protein containing nitrogen. There are more than 20 different amino acids – nine are essential, with lysine, methionine and threonine being the most important.

Antioxidants: Compounds that fight free-radical damage in the body and play a vital part in protecting all cell membranes. They are found naturally in grass and fresh foods, as well as in compound feeds and supplements.

As fed: Weight of the feed including water – the opposite of “dry matter”.

B is for . . .

Balanced ration: A balance of forage and concentrates supplying the correct proportions of all required elements (water, protein, energy, vitamins and minerals) for the individual horse.

Balancers: Concentrated formulations of nutrients carefully prepared to balance the nutritional input of feed.

Bioflavonoids: Water-soluble substances boasting various health benefits and found in plants. They are particularly useful in maintaining the function of small blood vessels.

Biotin: Biotin belongs to the B vitamin group, and is synthesised naturally by micro-organisms in the horse’s hindgut – it is necessary for the metabolism of protein, fat and carbohydrate.

C is for . . .

Calcium: A mineral essential for maintaining strong bones and teeth.

Carbohydrates: Compounds containing carbon, hydrogen and oxygen. Simple carbohydrates (sugars) are derived from molasses and grass. Complex carbohydrates (cellulose and starch) are derived from fibre sources and cereals.

Most simple carbohydrates dissolve easily in warm or cold water, whereas complex carbohydrates must be broken down by enzymes in the gut.

Cellulose: A complex carbohydrate that is the main constituent of plant cells.

Cereals: The edible grains of varieties of plants, such as barley, oats, maize and wheat.

Chelation: The manufacturing process of bonding a mineral to an amino acid in feed to make it easier for the horse to digest.

Choline: Part of the B vitamin group, which is vital for maintaining a healthy liver.

Chondroprotective agents: Compounds that are reputed to regenerate cartilage and promote joint function. They include glucosamine, which aids the production of synovial joint fluid, and chondroitin sulphate, which prevents cartilage degradation. Chondroprotective supplements can be fed both as a preventative measure and to ease existing joint problems.

Cobalamin: Otherwise known as vitamin B12, it is vital for enzyme function. Often used for the treatment of anaemic conditions.

Cobalt: Trace element – essential for cobalamin (vitamin B12) synthesis.

Compound feeds: Manufactured feeds, such as cubes, pellets and mixes, containing energy sources, fibre, proteins, vitamins and minerals.

Copper: Trace element – essential for muscle function and haemoglobin, keratin and cartilage formation.

D is for . . .

Digestibility: The extent to which feed is converted into useful substances for absorption and use within the body.

Digestible energy: The quantity of energy – measured in megajoules (MJ) – absorbed by the horse after eating.

Dry matter: The quantity of feed after the removal of water, as opposed to “as fed”. Dry feeds contain around 90 per cent dry matter.

E is for . . .

Electrolytes: Minerals and mineral salts found in body fluids, sometimes given as an additive to replace minerals lost in sweat.

Enzymes: Proteins produced within the digestive system that help to dissolve food.

Essential fatty acids (EFAs): Fatty acids needed for bodily functions, including tissue repair – they must be obtained from the diet. Found in oils such as soya, corn, wheatgerm and cod liver oil.

F is for . . .

Fibre: Essential dietary component. Some fibre sources are more indigestible than others for horses – for example, straw is less digestible than grass. Hay, grasses and chaff are high in digestible fibre. Fibre sources are broken down by micro-organisms in the hindgut.

Folic Acid (folate): Formerly known as vitamin Bc, folic acid works closely with vitamin B12 to produce red blood cells and haemoglobin.

Forage (fibre): Bulk food such as hay, haylage and hay replacers – provides energy and promotes efficient digestion.

Formula: Ingredients and their levels within a ration, just like a cooking recipe.

Free radicals: Damaging molecules produced in the body’s cells as part of metabolism. Stress increases their production.

Fructans: Compounds of fructose (complex or ‘storage’ carbohydrates) found in grass – an excess of which is linked with laminitis.

G is for . . .

Glucosamine: An amino derivative of glucose involved in the regulation of cartilage growth and repair. The horse’s body can make glucosamine from glucose and amino acids, but it can also be sourced directly from the circulatory system.

Glucose: Sugar molecule found in the tissues of most plants and animals.

Glycogen: The main form of carbohydrate storage, which occurs primarily in the liver and muscle tissue of mammals (the plant equivalent is starch). Glycogen is readily converted into energy-producing glucose.

H is for . . .

Haemoglobin: A conjugated (coupled or one of a pair) protein that transports oxygen from the lungs to the body tissues.

Haylage: Bagged, preserved grass, baled when the grass wilts. Haylage contains 30-40 per cent moisture.

Heating: Usually applied to the effect of a feed on the horse – refers to the horse being hot-headed rather than the digestion process of fibre, which produces heat.

Herbs: Wide variety of plants with medicinal or healing properties.

Hydroponic forage: Fresh shoots of germinated barley, fed in conjunction with other forages.

I is for . . .

Inositol: Part of the B vitamin group, vital for maintaining a healthy liver.

Iron: Trace element essential in the formation of haemoglobin.

Immunomodulators: Substances that suppress or strengthen the horse’s immune system. Echinacea is a widely used herbal immunomodulator.

Inorganic nutrient: Mineral mined from the earth.

Inter-relationships: Relating to the dependency of nutrients on one another within a feed ration.

Iodine: Trace element essential in healthy thyroid growth and function.

L is for . . .

Lactic acid: Organic water-soluble liquid produced in the muscles, required for the body to function. A synthetic form is used as a preservative and also in pharmaceuticals. Large amounts of lactic acid are usually produced during strenuous exercise.

Lysine: Essential amino acid required for an animal’s optimum growth.

M is for . . .

Magnesium: Mineral required for bone and tooth growth.

Malabsorption: The inability to digest nutrients.

Manganese: Trace element with antioxidant properties – essential for normal growth.

Measurements: Feeding measurements include pounds (lb), percentages (%), milligrams (mg), grams (g) and parts per million (ppm).

Metabolism: The process of digesting feed to utilise the nutrients contained within it.

Methionine: Essential amino acid containing sulphur, obtained from proteins.

Micronutrients: Nutrients required in very small quantities.

Micronised: Cereals cooked to increase the digestibility of starch.

Minerals: Inorganic nutrients (macro minerals or major minerals) are included in feed in relatively large amounts, while minor minerals or trace minerals are added in small amounts.

MSM: Methyl sulphonyl methane – a sulphur compound which supports joint formation.

Mycotoxins: Toxic compounds produced sporadically from moulds on feed. (Most feed companies test for mycotoxins, but they can also be present on hay).

N is for . . .

Niacin: Vitamin B3, for healthy skin and digestion.

Nutraceutical: Nutritional components credited with pharmaceutical properties. Not drugs.

Nutrients: Essential compounds such as protein, oil, fibre, starch, vitamins and minerals.

O is for . . .

Oil: Nutrient useful for adding coat shine and also fed as an energy source. Variations include soya and linseed oils, vegetable oils and fish oils.

Organic nutrient: Nutrient source of vegetable origin, as opposed to being mined from the earth.

P is for . . .

Pantothenic acid/pantothenate: Vitamin B5, required for the production of antibodies for immunity.

pH: Value given to acidity/alkalinity levels – 1 is very acidic, 14 is very alkaline.

Phosphorous: Mineral important for bone formation – must be in correct ratio with calcium.

Potassium: Metallic element found in forages – required for muscle metabolism.

Prebiotics: Complex sugars which stimulate microbial growth in the digestive system. MOS (mannan-oligosaccharides) are thought to remove bacteria by binding to them in the small intestine. FOS (fructo-oligosaccharides) are fermentable food sources which increase acidity in the hindgut. Prebiotics can be given as additives in feed.

Probiotics: Live bacterial cultures thought to balance microflora in the foregut. They can be given as additives.

Prohibited substance: A substance (drugs, certain feed sources and some herbs) which can enhance a horse’s performance. Governed by The Jockey Club and the FEI, which have a pre-defined list. Among the most commonly known examples are testosterone, caffeine and valerian.

Proteins: Linked amino acids needed for body tissue formation and repair (see amino acids). Good sources of protein for the horse are linseed, soya and alfalfa. Nutritionists measure the crude protein content of feed by measuring nitrogen levels.

Pyridoxine: Otherwise known as vitamin B6, it is essential for energy production.

Q is for . . .

Quidding: The term used when a horse drops partially-chewed food from its mouth.

R is for . . .

Riboflavin: Vitamin B2, vital for the metabolism of proteins and carbohydrates.

S is for . . .

Selenium: Selenium is a trace element with antioxidant activity. It is purported to have anti-inflammatory properties.

Silage: Grass cut when wet (‘pickled’ grass). It is a livestock feed, not suited to the horse’s digestive system.

Statutory statement: A legally required statement found on feed labels, indicating the purpose of the feed and stating its contents.

Starch: Complex carbohydrate which is digested to become glucose. Found in cereals.

Stomach: The horse’s stomach accounts for 10% of the digestive capacity and holds around 14 pints of liquid. It produces acid continuously.

Straights: Non-mixed hard feed – in other words, a feedstuff purchased on its own rather than in a compound mix.

Succulents: Fruit, vegetables and sugar beet – usually fed as a treat, to add variety to a meal or to increase water intake.

Sulphur: Non-metallic element required for the formation of amino acids.

Supplements: Nutrients and additives given as regular additions to the horse’s diet. Broad-spectrum supplements include a wide range of micronutrients, while specific supplements are designed for a particular purpose or function.

T is for . . .

Thiamin: Otherwise know as vitamin B1, thiamin is required for metabolising fat and carbohydrate efficiently, and normal neural activity. Thiamin is found in yeast and the outer layer of cereal grain.

Threonine: Amino acid obtained from protein – an essential nutritional component.

Trace elements: Minerals essential to the horse’s diet – the following trace elements need to be included in the diet in small amounts: copper, cobalt, zinc, iodine, iron, manganese and selenium.

U is for . . .

Utilisation : The body’s ability to use nutrients efficiently and to good effect.

V if for . . .

Valerian: Prohibited herb with sedatory effects.

Vitamins: Organic substances essential for healthy bodily function. There are two types of vitamins:

• fat-soluble, which can be stored – these are vitamins A, D, E and K
• water-soluble, which are required daily – these are vitamin C and the B complex group of vitamins.

The horse’s system is able to produce some water- and fat-soluble vitamins.

Volatile fatty acids (VFAs): These are the end product of fibre breakdown, and are utilised as an energy source.

W is for . . .

Water: The most essential nutrient, because it carries other nutrients around the body. The body tissues of young horses contain approximately 70-80% water, compared with 60% in veterans. Water has no energy value and is found in most feeds at some level.

Weight conversions: A useful method of converting metric weights (kilograms and grams) to imperial weights (pounds and ounces):

1,000 micrograms (mcg) = 1 milligram (mg)

1,000 milligrams = 1 gram (gm)

1,000 grams = 1 kilogram (kg) = 2 pounds (lb) 3.2 ounces (oz)

28.35 grams = 1 ounce

453.6 grams = 1 pound

Y is for . . .

Yeast: Fungi that stimulate microbial fermentation in the horse’s hindgut.

Z is for . . .

Zinc: Trace element essential for promoting healthy tissue growth.

This feature was first published in the February issue of HORSE magazine. Don’t miss the March issue of Horse, which is on sale on 5 February.