The nutritional needs of all dogs are divided into energy (carbohydrates, fat), protein, minerals and vitamins. The first need of the dog concerns its energy expenditure. Indeed after water, the energy constituents are those whose deprivation affects the dog's health as quickly as possible. The energy richness of a ration comes mainly from carbohydrates and lipids. Daily energy expenditure includes those due to basic metabolism * (the energy expenditure of the animal when it is completely at rest), which represents 60% to 70% of the total energy expenditure, to which is added the loss of energy, Energy related to muscular work, digestion and thermoregulation.
The energy requirements of the dog are of the order of 132 Kcal EM / kg PV0.75
(ME: metabolizable energy - PV0.75: metabolic weight).
GLUCIDS (sugars (glucose) and starch)
They provide energy to the body. The liver and muscles absorb the glucose present in the blood to assemble them into glycogen which represents a form of energy storage in animals. The digestion of starch is a factor to be taken into account, due to a weak amylase activity in dogs. A suitable physical-chemical treatment will allow to obtain a maximum digestibility of this one. Lipids (provided by the fat) form the concentrated and privileged source of energy. They release about twice the energy per unit weight compared to carbohydrates. They are indispensable to the organism not only for their energy role but also for their plastic and functional roles.
They provide so-called EFAs (long-chain polyunsaturated fatty acids (C18 to C22)), which are the constituents of the membrane structure of the cells. They are essential for the maintenance of the latter and for the proper functioning of the cell, They have a key role in growth, hair beauty and skin preservation, hepatic and cardiac function, and fertility and coagulation.
Essential elements of food, their primary role is to provide the body with the elements necessary for its construction. They provide the amino acids necessary for the synthesis of tissue proteins in the body, and as such contribute to the growth and maintenance of "lean" tissues: muscles, nervous system and skeleton. Some of these amino acids can not be synthesized in sufficient quantities by the body and must therefore be provided by the diet, they are the essential amino acids. Amino acids are involved in many biochemical cycles that are essential to life. By chemical modification, certain amino acids are transformed into important biological molecules involved in the phases of growth, neurotransmission, allergic reactions and in many other hormonal functions.
MINERALS AND VITAMINS
They are essential to the proper functioning of the body. They participate in many metabolic reactions. As with other food ingredients, excesses are as dangerous as deficiencies, hence the importance of a well-adapted food.
Essential to cell maintenance, vitamins perform many functions. They help to transform food into assimilable substances and participate in the development of blood cells, hormones and various chemical components of the nervous system. They come in many functions such as vision, growth, reproduction, protection of cells, growth of blood cells and almost all metabolic and energy reactions. Minerals form the major part of the skeleton and teeth. They are used to maintain the immune system, to coagulate blood and to metabolize oxygen in the body. They also transport energy, water balance, and they enter the bone and epidermal metabolism.
The main qualities of the food will be to meet all these needs and be attractive to the animal. The notion of need will then have to take into account not only the expenditure levels of the animal (with all its factors of variation: physiological state, physical activity) but also the yields with which the food intake will be used, again many Factors of variation, linked to the animal (breed, individual ...), as well as to the food (quality of components, manufacturing technology, nutritional balance, ...).
A balanced diet will cover quantitative needs (energy) and qualitative needs (essential substances).