What are the nutrients found in a nutritionally
complete and balanced dog food? How do they interact with one
another? Understanding the purposes and the interrelationships
of nutrients assures the pet owner that feeding a high quality
dog food provides the nutrition a normal healthy dog requires.
Protein
Protein is found in every living thing, and is an essential component
of all body tissues. In the body of the dog, over half the dry
matter is protein. Dietary protein is necessary for the growth
and maintenance of almost all tissues of the body, including
muscle, hair, bone and organs. Protein not used for these functions
can be utilized for energy.
Protein deficiency symptoms in the dog include depressed appetite,
poor growth, loss of weight, rough and dull haircoat, irregular
estrus, lower reproductive performance and reduced milk production.
A protein molecule contains 23 different amino acids. Their arrangement
determines the nature of the protein. Proteins in the foods are
broken down into amino acids by digestion. They are then absorbed
and distributed by the bloodstream to the body cells which rebuild
these amino acids into body proteins.
There are two types of amino acids: essential and nonessential.
Amino acids are termed essential when the |
body cannot manufacture them in adequate
quantities, but they are required by the animal and therefore
must be present in its diet. The absence or deficiency of even
one essential amino acid will influence the utilization of all
others. Nonessential amino acids are manufactured by the body
in sufficient quantity.
Ten amino acids considered essential to the dog are histidine,
isoleucine, leucine, arginine, methionine, phenylalanine, threonine,
tryptophan, valine and lysine.
The quality of protein, depends to a large extent upon its amino
acid content. Diets that furnish an insufficient amount of any
of the essential amino acids are said to have proteins of poor
quality. Those that provide the proper proportions of the necessary
amino acids are said to supply proteins of good quality.
A combination of protein sources generally provides a better
amino acid balance than just one protein source. One protein
source has a different amino acid pattern than another. By combining
two or more sources, a better amino acid balance is established.
Many plant proteins are excellent sources. A balanced ratio of
plant protein amino acids or a combination of plant and animal
protein amino acids and their proper processing provide the dietary
protein needed for all stages of a dog's life.
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Fat
Fats in the diet of the dog are concentrated forms of energy.
Per unit of weight, fats contain two-and-one-fourth as much energy
as an equivalent weight of protein or carbohydrates. Fats contribute
to the palatability of the diet and influence the texture of
pet foods, supply essential fatty acids and carry fat-soluble
vitamins (A, D, E, and K).
Fats and fatty acids are components of hair and skin. When a
deficiency occurs, the haircoat becomes dry and coarse and the
skin becomes dry, thickened and flaky. Other deficiency signs
include fat-soluble vitamin deficiencies, retarded growth in
puppies (4-6 months old) and even death in an advanced fat deficiency.
Excess fat in the diet may satisfy the energy needs of dogs before
its requirements of other nutrients have been met. Fat supplementation
of a good-quality nutritionally complete and balanced diet is
usually not necessary.
Fiber
Fiber is a collective term for plant tissues found in the stems,
leaves and seeds of plants. It is sometimes described as "rough-age"
or "bulk." Although dietary fiber is relatively a non-digestive
nutrient, its presence in the diet of the dog is beneficial as
it aids in gastrointestinal functions. Fiber helps food residue
to pass through the intestine and also contributes to fecal consistency
and firmer stool formation.
Fiber is important in diets designed for weight reduction or
weight maintenance such as Purina Fit and Trim brand dog food.
It helps reduce caloric intake while producing a feeling of satiety
or fullness for dogs on restricted feeding levels.
Minerals
A delicate balance of minerals is necessary in the diet of the
dog. Although minerals are essential for bone and tissue development
and proper functioning of the body, too much or too little of
certain minerals can have |
