Nutrients

The major nutrients, required in substantial quantities by every animal, include:

Carbohydrates, which provide the body with energy, and in surplus, will be converted into body fat.

Fats, which are the most concentrated form of energy, producing more than twice as much energy, weight for weight, than carbohydrates, and which will also convert to body fats if supplied in excess.

Proteins, which essentially provide the body-building elements in the diet.
 
The minor nutrients include the vitamins, minerals and trace elements, which, although critical to the animal's health, are required in comparatively small amounts. The vitamins are usually divided into two groups:

Fat soluble: vitamins A, D, E and K.

Water soluble: the complex vitamins and vitamin C.