Alison Perera wrote in message ...
In article ,
(Steve Crane) wrote:

If you want to compare products you ought to compare products within
the same category. Both Wellness and Felidae are "All Life Stage"
foods, which means they have passed AFFCO testing for growth and are
indeed "kitten" foods. Therefore the correct comparison would be to
compare one growth food to another.

Steve,

Chris and I went around and around on this topic recently. What
requirements are there for a product to pass the AAFCO (I assume that's
what you mean) feed trial for growth, other than having 8 kittens
consume the food for 10 weeks and show no significant nutritional
deficiency or stunting of growth? Theoretically speaking, if one were to
submit Science Diet Adult Maintenance to an AAFCO growth trial, would it
have any chance of passing?

-Alison in OH

Alison,
AAFCO has two methods of approving a food. For many years there was
only one method and that involved an actual feeding trial. A few years
ago AAFCO got weak (my personal opinion) and permitted a manufacturer
to show that one food was similar to something else they already run
through feeding trials and therefore it wasn't necessary to actually
run a feeding trial. (Similar formulas expected to provide similar
results philosophy) You can tell the difference because the legal
AAFCO statement either uses the word "feeding" in the language of the
statement or doesn't.
There are essentially two forms of actual feeding trials. One is
for growth and the other is for adult maintenance. There is no feeding
trial for "All Life Stages". It is presumed that if a food can
satisfactorily pass the more strenuous growth test than it will
provide sufficient nutrition for adult maintenance. Feeding trial are
not deigned ot look for long term effects of excessive levels of
anything. The growth trial requires that puppies in the trial be fed
the food and that blood tests be taken every week during the trial.
PCV, RBC, WBC, and typical serum chemistries must remain within normal
ranges during the entire trial period or the food fails. Puppies and
kittens are growing at an enormous rate during this time and need
vastly greater quantities of calcium, phosphorus, fat, protein etc
than an adult dog or cat which isn't growing at such a prodigious
rate. And no, it's not as simple as the *amount* of food needed. The
ratio of protein to total energy intake is vastly different when you
are doubling in size during the trial period.
In contrast the adult trial requires the same blood test each week
and must deliver the same consequences at the end of the trial, but
the animals involved are not doubling their weight during the trial
and thus need far fewer amounts of many nutrients.
Science Diet adult products are designed and developed for adult
animals, not puppies or kittens and thus would not be subjected to the
growth trial. It would be purely a guess on my part, but I would guess
some might pass and others might not. Science Diet puppy and kitten
products could be labelled for "All Life Stages", however Hill's feels
this may mislead a pet owner into feeding a growth product to an
adult. Hill's has a tradition and history of treating disease with the
Prescription Diet products. As a consequence the level so fnutrients
like calcium and phosphorus that are so critical in renal failrue and
other diseases get particular attention. As a consequence dietary
development is always looking at the disease we see and trying to
avoid them. 50 years ago we saw pets in veterinary clinics with
examples of deficiencies in the diets, today we see only the results
of excesses in the veterinary clinic. (Outside of the occasional
animals dumped on the road and suffering from mal nutrition)