Page 179 - Raw Diet References Book 2019

Proposed Revisions Edited per Comments for 2014 Official Publication 12

elected to delete the previous maximum concentration of 1000 mg/kg DM that was
based on the maximum tolerance concentration recommended for swine rations. The
CNES noted that the swine tolerance of 1000 mg/kg DM was the greatest
concentration for any tolerance for zinc listed in the 2005 Mineral Tolerance of
Animals.
IODINE
The 2006 NRC RA for iodine in dog foods is 0.88 mg/kg DM. The FEDIAF
Guideline concentrations range from 0.9 to 1.5 mg/kg DM. In considering the basis for
these various recommended concentrations the 2007 CNES felt a recommended
minimum concentration of 1.0 mg/kg to be prudent and adequate to support adult
maintenance as well as growth and reproduction.
The 2007 CNES revised the maximum concentration for iodine based on the
following considerations. Although neither the 2005 Mineral Tolerances for Animals
nor the 2006 Nutrient Requirements of Dogs and Cats established a tolerance or SUL
for iodine in diets for dogs, both publications cite data that indicate a commercial
formulation containing 5.6 mg iodine/kg diet had adverse effects on thyroid
function. 16,17 FEDIAF also notes these studies, but faulted the studies for using a diet
deficient in calcium, phosphorus and potassium, and fed in excessive quantities. The
2008 FEDIAF Guidelines indicate a maximum concentration for iodine of 11 mg/kg
DM when other minerals are within acceptable concentrations and the products are fed
in appropriate quantities. The tolerances for iodine in the 2005 Mineral Tolerances of
Animals that have been established for various species range from 5 mg/kg DM in diets
for horses to 400 mg/kg DM in diets for swine. Given that the NRC tolerance for
horses is 10 times less than the general maximum concentration of 50 mg iodine/kg
DM recommended by AAFCO, the 2007 CNES felt the value of 50 mg/kg DM to no
longer be appropriate for setting a maximum concentration for iodine in dog foods.
The 2007 CNES acknowledges that additional studies may allow further refinement of
a maximum amount of iodine in foods for dogs, but until such data are available the
CNES felt it prudent to adopt the FEDIAF position and set 11 mg iodine per kg DM as
the maximum concentration of iodine in dog foods.
SELENIUM
The recommended minimum concentration of selenium was increased to 0.35
mg/kg DM in Adult Maintenance and Growth and Reproduction Nutrient Profiles
consistent with the 2006 NRC RA for selenium. The 2007 CNES notes there is a
difference between added selenium and total selenium content. The approval of food
additives for addition of selenium to animal feeds limits the total amount of selenium
that may be added to feed to 0.3 mg/kg from all approved sources on an as-fed basis
(90% DM feeds), roughly equivalent to 0.333 mg/kg on a DM basis. The
recommended minimum concentration of 0.35 mg selenium/kg DM in dog foods is the
sum of selenium from all ingredients in the product, both approved food additives used
specifically to add selenium to the product, as well as selenium contained as a
constituent of other ingredients. As there is generally more than 0.05 mg selenium/kg
DM in ingredients used to supply protein and fat to typical pet food formulations, the
2007 CNES believes the limitation of 0.3 mg selenium/kg DM from approved
selenium additives will not hinder a manufacturer’s ability to meet the minimum
recommended concentration of 0.35 mg selenium/kg DM.
Both the 2006 NRC and the 2005 Mineral Tolerance of Animals state no data are
available upon which to establish a SUL or tolerance for selenium in diets for dogs.
Both NRC publications cite the fifth edition of Trace Elements in Human and Animal
Nutrition published in 1986 for information indicating a dietary concentration of 5
18
mg/kg DM resulted in toxicity in dogs. The 2007 CNES acknowledges the NRC has
indicated in the years since the publication of the first edition of Mineral Tolerance of