Re: [pyrnet] Food issues

["Tracy" <espinay@bigpond.com>]

<< I am wondering if anyone can document the idea that a lesser (fat,
protein or whatever) type food influences the growth rate of bones at all?
>> Joe

There is a lot of research into to effect of different nutrients on growth.
Here are a few references I have readily to hand.  I can get more off
medline etc, but need some time to sit down and do it:

http://www.pedigreebreeder.com.au/features/nutrition/default.asp?s
"Protein nutrition is obviously still not completely understood,
however it is an essential part of every dog's diet. You can't give
too much protein in your dog's diet; however quality not quantity
makes the difference."

http://www.purina.com/breeders/magazine.asp?article=256
"Dietary protein requirements are much higher for growing puppies
than for fully grown dogs. In addition to supplying the protein needed to
support protein turnover and normal cellular metabolism, protein is
needed to build growing muscles and other tissues."

"Concern about protein causing developmental bone problems in
large-breed puppies has led some breeders to reduce the amount
of protein they fed. However, in research published in 1993 based on
studies of Great Dane puppies at Utrecht University in the
Netherlands, it was shown that dietary protein does not contribute
to these problems."

"Herman A. Hazewinkel, D.V.M., Ph.D., professor of veterinary
medicine at Utrecht University, led the research that found no detrimental
effects from protein levels up to 32 percent of the diet. However,
puppies fed a diet of only 15 percent protein showed evidence of
inadequate protein intake."

"Too low protein decreases the growth rate of puppies and also
their immunological response," Hazewinkel says. "This is true for large-
and small-breed puppies. An adequate protein level should be higher
than 15 percent."

"This study, conducted in young Great Danes during their first
half-year of life (my note - this may be important as they are only talking
of pups up to 6 months of age and not older) , concluded that dietary
protein increased to 32 percent does not negatively affect skeletal or
cartilage
development in these dogs. The research also confirmed that dietary protein
did not have detrimental effects on liver and kidney functioning."

http://www.eukanuba-eu.com/Portugal/dx3.htm
This article reiterates that high protein does not cause OCD or HD,
in either the hips or elbows:

Research into the growth of Great Danes (Nap RC, The
Netherlands,) has shown that the protein level of a diet has no significant
influence on skeletal development.  High protein intake does not result in
increased risk for OCD or HD, and there is no effect on the
development in the longitudinal growth of the bone."

In relation to other nutrients however:

http://www.vetmed.ucdavis.edu/iewg/nap.htm
"In addition to excessive calcium intake, researchers have shown
that over nutrition can also initiate these disturbances in skeletal
maturation and growth.  An excess protein intake, without an
excess of other nutrients revealed NOT to influence skeletal maturation and
growth in growing Great Danes (Ref. 2)."

"Disturbances of skeletal growth were also seen in research
animals (Great Danes), which were energy restrictedly raised on a food with
a normal calcium level (1.0~56 calcium on dry matter base,
according to the requirements of dogs as followed by many of the
manufacturers and owners for dog food preparation).  Therefore we now advise
to raise dogs, vulnerable for these skeletal diseases, on a balanced food
with a calcium content decreased to 0.8 or 0.9% on dmb (dry matter basis)."

"Therefore it is advised not to feed young dogs ad libitum or
excessively, to prevent the development of (causative factors for)
osteoartrosis.  It is also common practice to advise a weight loosing
programme to those dogs which suffer from osteoarthrosis as an
aspect of conservative treatment or as an aid in surgical treatment of dogs
with ED."

http://www4.nas.edu/news.nsf/isbn/0309086280?OpenDocument
"The most obvious way to help a dog trim down is to feed it smaller
amounts of food on its regular feeding schedule......... Owners may also
choose a low-calorie "diet" dog food or food high in fiber, which may help
the dog feel full without consuming too many calories.  Too much fiber,
however, can reduce the absorption of important nutrients."

Tracy Bassett
Murrumbateman, Australia
espinay@bigpond.com