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Animal Nutrition

The scientific composition of feeds and the feeding of livestock from day to day is known as nutrition. The food compounded for farm animals is called feeds. They consist of various types of food sources called feeding stuffs. Each feeding stuff is made of water and dry matter. The dry matter consists of organic and inorganic materials. Each feeding stuff supplies one or two essential food or body requirements called nutrient. While the inorganic material of the dry matter of a feeding stuff provides minerals, the organic matter consists of carbohydrate, fats, protein and vitamins. The purpose of which animals are kept helps to determine the type and quantity of each feeding stuff to include in a feed. For instance, the feed composition of layers is different from that of broilers or breeders. The total feed provided for animals per day is called ration.


Major composition of food


Nutrients are chemicals or essential body requirements supplied by feeding stuff. Animals need some of them in large amounts and others in only tiny amounts. Nutrients are of various types, each performing different jobs in the animal’s body. These types are:

(i) Carbohydrates
(ii) Fats and Oils
(iii) Proteins
(iv) Minerals
(v) Vitamins
(vi) Water

1. Carbohydrates and its functions
Carbohydrate is in other word called Energy Nutrient. With the exception of water, the energy feed usually make up the greatest bulk of feed. It is the body’s fuel, always burning or reacting in the body to release ‘fire’ (energy). Remember, you need energy or ‘fuel’ to power the movement of muscles to walk, breathe, blink the eye, contract the digestive system, etc. While these activities go on, heat is produced to warm the body.

There are the simple and complex carbohydrates. All carbohydrates are made up of carbon, hydrogen and oxygen (CHO). The type of carbohydrate depends on the possible combinations of the three elements. Sugars and starches are simple carbohydrates while cellulose contained in roughages is one of the complex carbohydrates. Grains and tubers contain sugar and starch respectively and are easy to digest.

2.   Fats and oils and its functions
Fats and oils is another group of energy nutrient. Fats supply more energy than carbohydrates for movement and heat. It promotes the absorption of vitamin A and calcium. Fats may be supplied in concentrates such as cotton seed, soya bean and groundnut cakes and fish meals. Fats are solid at body temperature, while oils are liquid. Both are called fats. It is made up of carbon, hydrogen and oxygen. It contains more percentage of carbon and hydrogen atoms and less of oxygen than carbohydrate.

3.   Proteins and its functions
The body cells and tissues are made of protein. Protein therefore serves as ‘bricks’ and ‘motar’ from which the body is built. When feeds containing protein (meat and fish meals, soyabean and groundnut cakes and forages) are eaten and digested, they eventually become muscles, internal organs, blood, milk, egg, skin, hair, wool, horns, and many other parts of the body.

Protein is of different types. Each type is made up of a combination of nitrogen with carbon, hydrogen and oxygen. Some more complex form of protein combine nitrogen with carbon, hydrogen, oxygen, sulphur and phosphorus or iron (CHONSP) acid. When excess protein is fed, the nitrogen portion of the protein is separated from the nutrient and passed out as urine, while other materials are converted into energy for

4.   Minerals and its functions
Without minerals, many life processes will not take place. They harden the bones and teeth and egg shells of livestock, keep the body fluid and controls the power of absorption and the working of the body system. In the absence of iron in the blood for instance, oxygen cannot be carried to the body’s cells. Young pigs suffer from anaemia disease because the dam’s milk they suck lack iron and copper. Calcium and magnesium aid the formation of bones, teeth and shells of eggs.

Minerals are inorganic chemical substance because they do not contain carbon. It is needed in the body in very small amounts for chemical reaction. Such minerals include iron, copper chlorine, iodine, calcium, phosphorus, magnesium and potassium. Minerals are provided in feeds such as fish, meat, blood meals, oysters, salt licks and additives.

5.   Vitamins and its functions
Vitamins are complex chemical substances extracted from feeds. They are very vital but are needed in much smaller amounts. Vitamins are essential for normal growth and development though they do not contribute to energy or tissue repairs of the body. Vitamin-free feeds give rise to deficiency disease such as rickets, scurvy, infertility, abortion, ketosis, etc., and may even cause death. Vitamins are grouped as fat-soluble and water-soluble.

a.  Fat-soluble vitamins
These are extracted from feeds with fat solvent and designated as A,D,E and K.

Vitamin A – It is responsible for good eye sight and health of the tissues of nasal passages and lungs. Its deficiency causes night blindness and infections of the respiratory system. It is obtained from green plants, milk, oil, carrots, fruits, eggs and fish.

Vitamin D – It is responsible for the strength and proper development of bones and teeth, for example, shells and the mineral balance in the blood. Its deficiency in feed causes crooked bones of the legs and decrease in egg laying and hatch ability. It is obtained from sun-dried hay, fish, liver, oil, milk, fats, etc.

Vitamin E – It is responsible for normal production in hatching eggs. Its deficiency causes infertility and abortions. It is obtained from grains, cereals, oils of soyabean, groundnut and cottonseeds.

Vitamin K – It is responsible for blood clotting without which animal bleeds to death when wounded. It is obtained from green forages, liver, egg-yolk and fish meals.

b.  Water-soluble vitamins
These are extracted from feeds with water solvent and designated as B and C.

Vitamin B – Vitamin B which is found in different forms has the B complex promoting growth, stimulating appetite and maintaining digestion to release energy. Vitamin B12 and folic acid are responsible for the formation of red blood cells, normal skin and sound nerves. The deficiency of vitamin B causes indigestion, constipation, loss of appetite and weight, nervous depression and also promotes slow heart beat. It is obtained from green forages, well-cured hay and silage, grains, meat and fish.

Vitamin C – It builds up intercellular materials in the bones and keeps the gum healthy. Its deficiency causes scurvy ( swellings and bleedings) and weak bones. It is obtained from fresh fruits (tomatoes, etc.), leafy vegetables, potatoes. citrus fruits, etc.

6   Water and its functions
The body of kid, calf and lamb is three-fourth (3/4) water. Milk contains about 90% water while eggs contain about 60%. Therefore, its production requires a constant supply of water. An animal can live longer without food than without water. Remember also that water forms a major component of the feeding stuffs. But the water content of forages is often so low in the dry season that free water must be made available. All
domestic animals require access to free water, some daily and some at frequent intervals.

Water performs some major functions in the body of animals. It forms most of the blood which carries nutrients to cells and carries waste products away. It helps digestion and absorption of food materials. As a built-in cooling system, it regulates body heat and acts as a lubricant.