[Forwarded to FML at Dr. Willard's request.  BIG]
 
Bob C. goes to great lengths to explain to his readers and does a pretty
good job of explaining a complicated issue.  However, he has made a basic
error.
 
Regarding his comparison of a rat, Baby food and TF, he made a math
error.  In a 100% DM calculations if you subtract the 40% protein and
the 24.4% fat and 7.2% ash plus 1.15% fiber from 100%, you get 26.4% NFE
(nitrogen free extract).  NFE is not true carbohydrates but is the math
difference of the equation.  Bob had all of the major nutrients but the
fiber but I do not know where he came up with 37.7% carbohydrates.
 
We have sent our diets as well as competitors to outside laboratories
and found, over the years, that the NFE averages about 70 to 75% starch,
which is a true carbohydrate.  So going back to Bob's calculation, the
26.4% NFE X 0.75 = 19.8% starch or true carbohydrate.
 
Now, to a finer point.  From the very beginning, when we developed TF,
as with all of my formulations for carnivores, I have always over
formulated to compensate for the natural nutrient variation present
in all ingredients so we will never be below our guarantees.  We have
analyzed every manufactured batch of TF for the past 12 years.  The
average analysis for TF is 37.2% Protein, 24.3% Fat, 1.15% Fiber,
Ash 6.8%, 7.5% moisture and NFE is 23.05%.  Therefore, on a DM basis
this means 40.2% Protein, 26.3% Fat 1.25% Fiber, 7.4% Ash and 24.9% NFE.
Converting the NFE to true carbohydrates 24.9% x 0.75 = 18.7%.
 
Having shown this based on our actual data, what does it prove or show?
It proves that TF has been very consistent in delivering our nutrient
guarantees.  It shows that the Carbohydrate level of our food is one of
the lowest on the market.  It means nothing else.
 
There are a couple of ferret diets on the market that raise the protein
and fat level simply to lower the carbohydrate levels.  They use low
quality vegetable and animal proteins that are poorly digested but they
then claim "low carbohydrates".  What is 'low"?  What is "high"?  What
should the level be?  Is 15% carbohydrate better than 20%?  Is 10%
still better?  Is 0 ideal?  How do we know?  Is there anyone that can
definitively answer this?  Can we be too low in carbs?  Whole animals
have very digestible carbohydrates which is basically glucose.  Should we
add glucose or other highly digestible sugars to our diets?  Should only
fresh meat be fed?  What about the vitamin and mineral levels?  If we
feed fresh meat, as Bob points out, we must balance the minerals - all 16
essential ones.  The domestic ferret is not equal to its wild ancestors.
It lives in an entirely different environment.  It does not hunt nor is
it hunted.  My point is, there are many unanswered questions concerning
the nutrient requirements of ferrets.  It took years to establish the
basic nutrient requirements for the dog and cat.  I know, because I was
involved in the 70's and 80's in the research.  The first prepared food
for dogs was developed in the late 1800's but it took until the '70's to
develop the economic interest to fund the 10 year studies.  By the way,
this research has continued and billions of dollars have been spent by
private industry to further our knowledge of cat and dog health and
nutrition.
 
There has been a great deal of effort over the past years to show a
connection between diet and the incidences of insulinomas but no one
has ever done more than provide anecdotal information.  I have reviewed
several papers during this time asking for my scientific input and it
has always been the same.  There is no research that even gets close to
showing a connection between diet and this complicated disease.  My
biggest concern is not that there is a connection but that if there is
some linkage that the true cause may be overlooked because everyone is
so intent on "proving" the diet connection.  I am not criticizing those
that are concerned for there ferret's health, as it is a devastating
disease, but just because it seems there should be a direct cause and
effect, it may not be.
 
There is evidence that insulinomas are genetically linked, which may
indicate a breeding connection.  Many non US bred and raised ferrets,
eating prepared dry diets similar to the dry diets in the US, are not
showing nearly the incidence of insulinomas.  Why?
 
Kathy, there needs to be a lot of research on this disease as well as
others in ferrets.  I mean real scientifically controlled studies to
prove what is the cause.  Unfortunately, as in human studies, it will
likely take a long time and the results will not likely be a simple
answer.  If we have learned anything about cancer over the past 40 years
is that it is a multi system problem not a single cause.
 
I hope this helps and I apologize for the lengthiness but I feel that it
is important for all of us in the ferret community to look for answers
not excuses.
 
Tom Willard, PhD
Performance Foods, Inc.
[Posted in FML issue 4656]