Bob C and Bill K, thanks for the computational efforts!
 
OK so that means Iams canned kitten food is 45.3% protein and 32.8% fat,
which is 78.1% of the dry contents of the can.  That means no more than
21.9% carbohydrates for the canned food.
 
For dry food we have 40 + 24.4 = 64.4, which means no more than 35.4% for
carbohydrates.  But Bob says kibbled foods are 50% or more carbohydrates.
Please explain the discrepancy.
 
Bob has an excellent point about the biological value and digestibility
of protein.  This is why it is so darned hard to really compare foods.
Totally Ferret, for example, uses chicken by-product meal, which from the
definitions Gina Hart found, says may include nice things like intestines
and feet.  Chicken and chicken meal (flesh, skin and bone) may sound
better, since those less nutritious bits are not included, but note that if
you grind up a whole chicken to make Bob's chicken gravy, you are making
chicken by-product, since the neck and innards are included.  (By the way
feathers are diallowed by definition!)
 
So while one pet food says theirs is better because they use chicken and
chicken meal, another that uses by-products says theirs is better because
it includes organ meat and has higher protein value/digestibility than the
competition.  But NOBODY reports those numbers.  To some extent, price may
be a guide: more expensive food PROBABLY uses more expensive (better)
ingredients.
 
Linda Iroff
Oberlin OH
[Posted in FML issue 3029]