by
Susan Thorpe-Vargas PhD
Energy Sources
Puppies' high-activity levels require an almost continuous source
of energy. Hence the coloric density of their food needs to be
high, as puppies can ingest only so much at one time. This is
why puppy foods tend to have a higher fat content then other stage-of-life
foods.
Fats.
Fats are concentrated energy sources, about twice that per unit
of weight as carbohydrates and proteins. Fats provide more than
just energy. Not only are they necessary for the absorption of
the fat-soluble vitamins A, D, E and K, but the proper ratio of
essential fatty acids (EFA) is also extremely important. The two
essential fatty acids in the canine are linoleic acid (LA) and
alpha-linolenic acid (LNA), which fall into two classes--- the
omega-6 and the omega-3 fatty acids. Note that these EFAs cannot
be synthesized by the dog and therefore their needs must be met
by the diet. Two good food sources for LA are sunflower and sesame
seeds, and flax seeds contain LNA. It is generally believed that
these two EFAs should be combined in a 4 or 5-to-1 ratio (LA:LNA).
Why is this important? These two fatty acids are the building
blocks or regulators of transitory biological chemicals called
eicosanoids. This class of chemicals controls such diverse biological
processes as priming the immune system, keeping the circulatory
system in good working order and modulating sexual reproductive
hormones.
The developing immune system of the puppy is especially vulnerable
to an imbalance between the two classes of eicosanoids, which
could throw the above biological processes out of kilter. An imbalance
between LA and LNA in the diet could cause an inflammatory immune
response. Another concern for the consumer is that fats are particularly
vulnerable to oxidation, that is, they rapidly go rancid, and
generally are more difficult to preserve than carbohydrates or
proteins.
Carbohydrates.
Carbohydrates are starches, sugars and cellluloses. Canines can
only assimilate the first two, but an adequate amount of fiber
in the diet is necessary to maintain a healthy gut.
Carbohydrates have about half the energy content of fat and a
similar amount as proteins. It should be noted that some members
of this food group can be highly antigenic; that is they can provoke
an allergic reaction. The top three foods with respect to this
problem are soybean, wheat and corn. The canine doesn't absolutely
need carbohydrates as dogs are able to compensate for their lack
if fed a high- protein diet. This is not too surprising, considering
the dog's evolutionary development.
Proteins.
Proteins consist of long chains of amino acids. The dog require
some specific amino acids in their diet because they are unable
to adequately synthesize them and these are referred to as the
essential amino acids. The non-essential amino acids are just
as important but can be derived from other amino acids.
Young animals require more protein than adults to build the new
tissue associated with growth. The class of the dietary protein
must also be of sufficient quality so as to insure proper assimilation.
Feeding trials have determined that protein should provide no
less than 22% of the puppy's total coloric intake In fact, the
actual percentage of protein is not as important as the balance
between protein and available energy.