In animal feeds, the remaining energy from the raw energy by subtracting the following amounts of energy is called convertible energy, metabolizable energy or metabolic energy. The types of energy to be deducted from raw energy are:

·         Fertilizer energy in poultry

·         The energy lost by the manure, urine and fermentation gases in ruminants

In other words, metabolic energy is the energy obtained by subtracting the energy of the discharge products from the total energy in the dry matter of the feeds taken.

In simple terms, calories taken by nutrition are converted into energy by the body's metabolism. This energy is called metabolic energy. This energy is the energy required for the body to move. Under normal conditions, the human body needs 12 thousand calories per day. If this amount is missing, the world will weaken and if it is taken too much, the body starts to gain weight. Which foods contain how many calories must be written on their packaging.

Carbohydrates, fats and proteins are the leading energy-giving foods. All organic nutrients contain carbon, hydrogen and oxygen atoms. Cells do not use proteins as sources of energy unless they are required. The main task of proteins is to act as an enzyme in metabolism.

The smallest carbohydrates are sugar. Fructose and galactose taken together with foods turn into glucose in the liver and mix into the blood. Fructose is the sweetest sugar. Another sugar group is maltose (barley sugar), lactose (milk sugar) and sucrose (tea sugar). Starch is a polysaccharide. Excess glucose in plants is stored as starch. Starch is insoluble in water at all. Corn, wheat and potatoes contain large amounts of starch. Animals cannot produce starches, but take feed from the outside. This starch is broken down into glucose by the bodies and used.

In authorized laboratories, metabolic energy determination studies are carried out within the scope of chemical tests and protein, fat, starch and sugar analyzes are performed in foods and feeds. In these studies, globally accepted test methods are followed.