Proteins
are not derived solely from animal tissue; they are also available from
plants. Once consumed by an animal, digestion breaks protein down into
its constituent amino acids, then they are absorbed into circulation and
recombined into structural proteins needed by the animal. Animals can
make amino acids on their own, but not all of them. Although there are
23 amino acids, cats require that 11 of them be provided by the diet.
Twelve other can be synthesized in the body.
No single
protein contains all 23 amino acids. That means that a cat must eat
several different sources of protein in order to obtain all 11 of the
essential ones. The proteins from meat contain a greater variety of
amino acids than do proteins from plants.
Protein,
in fact, is a very questionable and controversial energy source, and in
most healthy animals should be avoided in excess. The cat is unique
among animals, however, because the cat is one species that actually
requires some of its energy to come from protein. This is one reason why
cats require more protein in their diet than dogs. The reason for this
species difference is not known, but is why they are recognized as true
obligate carnivores. This is a very important point. Cats should not be
fed dog food or a vegetarian diet!
Fats
serve several functions within the body. First, they are a highly
efficient source of energy. Fats are also necessary for the absorption
of some vitamins: vitamins A, D, E, and K. They are also important in
the formation of certain hormones. Fats are similar to proteins in that
they are made up of subunits called fatty acids. Two of the essential
fatty acids for the cat are required in their diet: linoleic and arachidonic.
Just as
there are different qualities of proteins, some fats are better than
others in providing essential fatty acids. Fats can be found in both
vegetable matter and animal tissue. Liquid fats like safflower and corn
oils consist of 50-70 percent linoleic acid. Arachidonic acid is found
only in animal fats. A cat’s requirement for arachidonic acid in the
diet is another factor that make it a truly carnivorous animal. Poultry
fat is an excellent source of arachidonic acid.
Vitamins
are used in the energy-producing reactions of the body. They are
important in wound healing, tissue repair, maintaining healthy skin,
haircoat and bones, and in blood clotting. Many animals, including dogs
and people, can synthesis some vitamins, such as vitamin A and niacin.
This is not true for cats. Cats require both vitamin A and niacin in
their diet. These vitamins are found in animal tissues and again, their
requirement makes the cat a truly carnivorous animal.
Vitamin
deficiencies are rarely a problem in healthy cats eating a wholesome
diet.
Vitamin
excesses are potentially a problem when cats are being fed home-cooked
diets. It is very difficult to balance these diets with the proper
nutrient levels, because the batches are small and the vitamin sources
are quite concentrated in comparison.
Minerals
serve as an important structural component in the body. Minerals are
needed in trace amounts in the diet. They are provided by both plant and
animal sources. Most of the minerals in cat food comes from bone and
meat meals used in formulation the diets.
Ash
in cat food refers to the mineral that is left when a diet is burned to
completion. A small percentage of cats are prone to a disease which
causes crystals to form in the urine. This disease goes by many names,
including feline bladder disease, lower urinary tract disease, or feline
urologic syndrome (FUS). It is thought that diet, particularly the
levels of magnesium (a component of the ash content in the diet), may
contribute to the formation of these urinary crystals. This has led to
the recommendation that cats be fed diets which contain less ash and
magnesium. Not all cats need to be on a low-ash/low magnesium diet, but
only those cats found to be prone to this disease.
Water
is the most important of the six basic nutrients. Most animals cannot
live more than a short time without it, or more than a few days without
becoming dehydrated and ill. Water comprises from about 95 percent of
the new-born kitten to about 75 percent of the adult cat. Water is the
body’s primary solvent for chemical reactions and life processes, and
maintains cell shape. |