Energy Feeds are also called Basal feeds, they are concentrated sources of energy and are especially rich in starches and sugars. Energy feeds make up 60 – 90% of all rations.

Energy feeds consists of feed ingredients that contain less than 20% of protein in dry state, less than 18% crude fiber and more than 60 percent TDN.

They are less bulky and have higher digestibility. They are concentrated source of nutrients and therefore, they have higher nutritive value than roughages.

Energy feeds primarily include the cereal grains, by-product feeds made from cereal grains, fruits, nuts, starchy roots, fats and oils, sugars and syrups, bakery products, barley, corn, molasses (dried), oats, oat groats, sorghum, wheat and wheat bran etc.

These are fed to ruminants and cecal fermenters to increase the energy density of their diets, and to monogastrics as the primary source of energy.

The cereal grains are very low in crude fiber, with a range of being about 2-10%. The lower the fiber levels, the higher the energy content tends to be. The energy values of grains is high, with the TDN as high as 90% on a dry-matter basis.

These values are high because of the high starch content, low fiber content and high digestibility. The protein digestibility ranges from 50-80%, but the protein quality is generally poor because the essential amino acid content of grains is poor.

Categories of Energy Feedstuff

Roots and tubers.

Cereal grains and by-products.

a. Starchy roots and tubers

Starchy roots (i.e. tubers and roots crops) most widely cultivated in tropical and sub-tropical part of the world are cassava, yams, cocoyam‘s and sweet potatoes in that order roots are also eaten in small quantities in some tropical countries.

In temperate countries, the most widely cultivated root crop is irish potato. Irish potatos are also grown in some tropical areas. Starchy roots contain large quantities of starch and so are high in energy per hectare than most cereals.

They are however, generally low in protein (1 – 4%) minerals and vitamins. Starchy roots form the major part of the diet of man in many parts of the world.

They are sometimes used in feeding of farm animals for example cassava and its products like gari, cassava flour or fermented cassava meal may be used to replace a large proportion or all of the grains in poultry and pig diets.

In using cassava, care must be taken to balance the diets for protein and amino acids, especially methionine. Starch and root crops are relatively easy to grow with high yield even on poor soils. They contain large quantities of starch and so are good energy source.

Types of Cassava

Manihot utilisima;

Manihot esculentus;

Manihot palmate.

It is a very popular tropical plants use in feeding man and all classes of livestock.

It is easy to propagate from stem cutting and is one of the most productive root crops in the tropical areas. Its yield is between 10 and 20 tons per hectare. It is available all the year round.

Cassava contains between 50 and 70 % water. It is low in protein (1 – 3 %), oil, ash and crude fibre (up to 5% CP can be obtained from some of the new variety).

The protein content of cassava tuber is deficient in lysine, methionine, tryptophan, tyrosine and phenylalanine but high in arginine. It is low in minerals and most vitamins but high in energy content.

The peels of cassava are richer in protein, oil and ash than the peeled portion. On a dry basis, cassava leaves have protein content that range between 14 and 69% DM. It is fair in lysine content marginal in tryptophan and isoleucine but deficient in methionine.

Cassava is able to serve as substitute to maize in livestock feeds at levels between 5 and 50 %, well processed cassava leaves and peels are widely fed to cattle, sheep and goats.

Limitations

Both the bitter and sweet varieties contain cyanide. The content of cyanide in fresh tuber of bitter varieties contain less than 100mg/kg. The peels contain 3 – 10 times more cyanide than edible portion.

Levels of cyanide less than 50mg/kg are considered harmless, 50 – 80mg/kg slightly poisonous, 80 – 100mg/kg toxic and above 100mg/kg fatal.

Symptoms of Eating Raw or Improperly Processed Cassava

Symptoms of eating raw or improperly processed cassava in man include feeling of sickness, nausea, vomiting, abdominal distention, respiratory difficulty and collapse.

Over a long period of consumption, raw cassava may cause goitre, deformed and mental defective cretinism, ataxia, neuropathy with mental retardation.

Detoxification

Cyanide is detoxified into thiocyanide and thus involves the use of sulphur. Some of these sulphur are obtained from sulphur containing amino acid. Cyanide also interfere with thyroid gland and therefore interfere with iodine metabolism.

However, much of the cyanide is removed during processing of cassava. The processing method include cooking, frying, boiling, washing, grating, soaking, fermentation and sun drying and long period of storage.

Properly processed cassava products are virtually free of HCN (hydrogen cyanide). High levels of cassava in feed make the feed to become dusty, hence molasses and oil may be added to reduce the level of dustiness.

The leaves and peels of cassava are widely fed to cattle, sheep and goats, although with fatal consequences sometimes.

Types of Yam

Water yam – Dioscorea alata

Aerial yam – Dioscorea bulbifera

Yellow yam- Dioscorea cayeneusis

Tritollate yam -Dioscorea dumetorium

Chinese yam – Dioscorea esculenta

White yam – Dioscorea rotundata

Yam is high in water content, high in soluble carbohydrate, low in crude protein (1-4%), low in fibre and fair in ash.

The protein content is low in lysine, methionine, tryptophan but contain appreciable amount of valin, arginine and isoleucine.

It also contains moderate amount of vitamin B complex and minerals. Yam peels are valuable as livestock feed especially in ruminant animals.

Limitation

The major limitation in the use of yam as livestock feed is the content of its major anti-nutritional factor (alkaloid) which can reduce the level of intake with time. It also has an itching effect on the palate.

Some varieties contain tannin up to 0.4% and saponin. However, most of these anti-nutritional factors are destroyed during cooking and drying.

Types of Cocoyam

Taro cocoyam, Colocasia esculenta

Tannia cocoyam, Xanthosoma sagittfolium

Cocoyam can be fed to livestock however, cocoyam should be cooked before being fed to livestock particularly pigs since the acid (Ca – oxalate) or sap toxin contained in the corm (swollen underground stem) is irritating to the digestive tract and may even be poisonous.

The pods and leaves of cocoyam are valuable feed for ruminants (cattle sheep and goats). Cocoyam are edible aroids. The big central corm is surrounded by smaller ones called cormels. The cormels are the commonly used as human food.

Cocoyams are high in water and carbohydrate contents. The starch of coco yam contains predominantly amylase and small amount of amylopectin. It is low in fat (less than 0.5%) and protein content.

Proteins of cocoyam have fair amount of the essential amino acids but are low in lysine and histidine. The peels are richer in oils than the inner content tuber. The leaves have higher nutrient content than the corms.

Limitations

Cocoyams are irritating to the body because of the presence of calcium oxalate in them. However, when boiled or roasted, the irritation disappears. The corms of cocoyam contain gastrogenic substance.

Sweet Potato

Sweet patato (Ipomoea batatas) comes in different varieties, it could be yellow or red colour.

It is cultivated in both tropical and temperate areas. Fresh potatoes contain 70- 80% of water. It is low in crude fibre, fat and protein.

However, the protein content have high biological value and it is rich in essential amino acid. On dry basis over 90% of sweet potatoes tuber is made up of carbohydrate. The carbohydrate is highly digestible when cooked but low when raw.

Much of the starch in sweet potatoes is converted to maltose during cooking (i.e. heat, enzymatic hydrolysis and starch) and this is responsible for the sweet taste in cooked sweet potatoes.

Potato tuber is rich in carotene and ascorbic acid (especially yellow varieties) and B-vitamin. However, storage and cooking reduce the content of vitamins.

It has fair amount of ash and minerals e.g. phosphorus, calcium sodium, chloride and potassium. Its leaves are rich in protein, minerals and vitamins.

Sweet potatoes are good for all classes of live stocks. The leaves and vines of potato are useful feed for ruminants.

Sweet potato has been used in diets of pigs and can be used in poultry diets along with suitable protein supplements. The leaves and vines of potato are useful feed items for cattle.

Cooked Irish Cooked Irish potato can be used effectively in the diets of pigs.

Sugars and Syrups

Sugars

Sugars are cheap and easily digested forms of energy. Sugars are obtained from sugar cane and sugar beet. After extraction, the crude sugar is refined and made into cubes (crystalline sugar).

Raw sugar, obtained from chewing the cane directly, contain small amounts of protein, minerals and vitamins. Refined sugars are however essentially carbohydrates and lack every other nutrient.

All white sugars i.e. crystalline table sugar, cube sugar, icing are practically 100% sucrose and are free of any toxic factors. Brown sugar is less highly refined sucrose and contains traces of other sugars, minerals and colouring matter.

b. Syrups

Syrups are highly concentrated solutions in which the sugar unable to crystallize out because of the presence of small qualities of other substances.

Some syrups, such as molasses and golden syrup are by-products of the manufacture of crystallize cane sugar. There syrups contain some amounts of protein (0.3%), Ca (0.03%) and Fe (1.5 mg/100g). They are devoid of any other ingredients.

Molasses

Molasses are mainly by-products of the manufacture of sugar from either sugar cane or sugar beets. Their sugar content is about 50-60% and water content is between 22% (beet molasses) and 27% (cane molasses). Beet molasses is higher in crude protein (7-11%) than cane molasses (3-4%).

Molasses have a mineral content of 8-10% composed mainly of sodium (Na) and potassium (K) salts. The Calcium and Phosphorus content are 0.10 and 0.02% respectively (for beet molasses) and 0.8 and 0.8% (for cane molasses).

The thiamine and riboflavin contents are each 0.05 mg/100g while the mean content is about 1.5 mg/100g. The iron (Fe) content is between 0.01 and 0.02%. The use of molasses in poultry diets is limited by its laxative effects when used at high levels.

Any level above 5% is laxative. Molasses may be used to prevent dustiness in mixed feeds and in the treatment of poultry blue comb diseases because of its sugar content. Molasses can be used at a rate of 3-5% in the diet of sows to help prevent constipation and enhance feed intake.

It is also used to ensile forage during silage production for ruminant animals. The difficulties in obtaining the product limit the use of molasses in animal diets.

Molasses is increasingly being used by human beings. It is sometimes used in place of honey.

Honey

Honey is made by bees. Most honeys (glucose and fructose) are known as the invert sugars. Honey also contains some protein (0.4%), minute traces of Calcium (0.005%), and small amounts of iron (0.4 mg/100g).

Honey also contains thiamine 0.05 mg/100g, riboflavin 0.05 mg/100g and niacin 0.2 mg/100g. Honey is an attractive, pleasant and sweet food.

Jams

Jams are prepared by boiling fresh fruit, or a pulp preserved with Sulphur di-oxide (sulphite pulp), with sugar. Depending on the antinutritional factors present in the raw materials, pectin may or may not be added. Jam is a general name for all such products.

Marmalade is synonymous to Jam in some parts of the world. Most jams contain about 65-70% sugar, 0.5% protein. It also has Calcium (0.02 – 0.04%), iron (1.2 mg), Vitamin A (2-10 mg/100g) and Vitamin C 10-45 mg/100g. Jams are pleasant, attractive and sweet foods.

Fats and Oils

The term fat general, referred to a group of food or feed ingredients including animal fats, vegetable oils and related compounds.

Technically, fats refer to those that are solid at room temperature for example butter, fallow and lard while oil is the term used to describe fats that exist as liquid at room temperature for example groundnut oil, corn oil, palm oil etc.

Fats and oils are concentrated sources of linoleic acid and linolenic acid (two essential fatty acids). Fats and oils may be a source of fat soluble vitamins.

Most vegetable oils contain significant amounts of vitamin E. Red palm oil is a rich source of beta carotene and hence a good source of vitamin A. corn oil contain small amounts of carotene.

Fish liver oils, milk fat (butter and milk) and animal fats generally contain vitamins A, and D. Most vegetable oils do not contain vitamins A and D.

Fat commonly included in livestock feeds (for poultry and pigs) can be divided into 6 general groups;

Animal fats:- these are rendered fats from beef or pork byproducts.

Blended feed grains animal fats: these may include mixtures of beef, tallow, pork lard, poultry grease and possibly restaurant grease

Poultry fator grease: This is rendered fat from poultry offal.

Vegetable oil: these are oils derived from vegetable materials for example groundnut, soybean, palm nut etc.

Blended animal and vegetable fats: these may include proportions of animal and plant fats

Soap stocks: This is also used in the manufacture of soap: these contain products not wanted in oil meant for human consumption including free fatty acids.

The use fats and oils in poultry and pig diets would depend on their price and availability relative to other energy source.

Fats should be used in diets where higher energy levels are required such as those for broiler chickens and turkey poults, weaning pigs, fast growing market hogs and lactating sows.

It is not economical to add any fat at levels above 5% in poultry and all fats used in animal diet should contain an antioxidant to prevent rancidity because raw oil seeds such as groundnut and soybean may deteriorate under certain circumstances. It is wise to use artificial antioxidants for preservation.

Some artificial or synthetic antioxidants are;

Butylated hydroxyltoluence (BHT, E321),

Butylated hydroxylanisole (BHA, E320),

Ethoxyquin,

Propyl galate and octylgallate.

In summary, energy feedstuff forms bulk of the feed ingredient in the feed of high producing animals. They are the main source of energy for monogastric animals.

In this article we have seen energy feed stuff contain high total digestible nutrients (TDN) and are crucial in animal production.

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