Page 196 - Small Animal Clinical Nutrition 5th Edition

198 Small Animal Clinical Nutrition

plant material has been treated with dilute acid and alkali solu-
Table 9-5. Guaranteed or typical analysis from the same dry tions. It is determined by a specific analytical procedure that
VetBooks.ir cat food as it would appear on pet food labels from selected was originally developed for the wood pulp industry and then
countries.

United States (guaranteed analysis) applied to animal foods. Although crude fiber is used to report
Crude protein Minimum 30.0% the fiber content of commercial pet foods, it usually underesti-
Crude fat Minimum 18.0% mates the true level of fiber in the product. Crude fiber is an
Crude fiber Maximum 2.0% estimate of the indigestible portion of the food for dogs and
Moisture Maximum 10.0%
Vitamin E Minimum 275 IU/kg cats (Chapter 5). The crude fiber method typically recovers a
Ascorbic acid (vitamin C)* Minimum 50 mg/kg large percentage of cellulose and lignin in a sample, and a vari-
Canada (guaranteed analysis) able percentage of hemicellulose and even ash.
Protein - 30.0%
Fat - 18.0% Moisture is determined by drying a sample of the product to
Moisture - 10% a constant weight.The drying procedure measures water in the
CVMA-Certified Food in Canada (guaranteed analysis) product as a whole, but does not distinguish between added
Crude protein Minimum 30.0%
Crude fat Minimum 18.0% water and water in the ingredients. Subtle differences in mois-
Crude fibre Maximum 2.0% ture content of moist products can result in marked differences
Moisture Maximum 10.0% in dry matter content and therefore the economics of feeding a
Ash Maximum 5.0%
Europe (typical analysis) given pet food. Remember, the dry matter content of the food
Crude protein - 31.3% contains all of the nutrients except water. For example, compare
Crude oils and fats - 21.3% the dry matter content of three different moist cat foods: 1)
Crude fibre - 2.0%
Crude ash - 4.7% Food A contains 72% moisture, 2) Food B contains 78% mois-
Moisture - 7.5% ture and 3) Food C contains 82% moisture.
Additives (per kg) Food A 100 - 72% water = 28% dry matter
Vitamin A - 17,100 IU
Vitamin D 3 - 1,710 IU Food B* 100 - 78% water = 22% dry matter
Vitamin E - 290 mg Food C** 100 - 82% water = 18% dry matter
Copper (copper chloride) - 21 mg *28 - 22 ÷ 22 x 100 = 27% more dry matter in Food A (72%
Contains EU permitted antioxidant
Contains EU permitted colorant moisture) vs. Food B (78% moisture)
*Not recognized as an essential nutrient by the AAFCO Cat **28 - 18 ÷ 18 x 100 = 55% more dry matter in Food A (72%
Food Nutrient Profiles. moisture) vs. Food C (82% moisture)
Therefore, what appears to be a small difference in water
content of a food produces a marked difference in dry matter
follow the listing of recognized nutrients and be accompanied content. Guarantees are expressed on an “as is” or “as fed” basis.
by an asterisk referring to the disclaimer “Not recognized as an It is important to remember to convert these guarantees to a
essential nutrient by the AAFCO Dog (or Cat) Food Nutrient dry matter basis when comparing foods with differing moisture
Profiles.”The sliding scale method of listing guarantees as per- content (e.g., moist vs. dry foods).
centage ranges (e.g., minimum 15 to 18%) is not allowed. It is Although a maximum ash guarantee is not required in the
important to recognize that these percentages generally indi- United States, many pet food manufacturers include one on the
cate the “worst case” levels for these nutrients in the food and labels of their foods. In the United States, “low ash” claims are
do not reflect the exact or typical amounts of these nutrients. not allowed because “ash” per se is of no true significance. “Low
This differs from pet food labels in Europe where “typical” per- magnesium” claims on cat food labels are allowed if the food
centages are used. meets certain FDA criteria. In such cases, a maximum magne-
The term crude protein refers to a specific analytical proce- sium guarantee is required. To be labeled as a “low magnesium”
dure that estimates protein content by measuring nitrogen. food, the product must contain less than 0.12% magnesium, on
Crude protein is an index of protein quantity but does not indi- a dry matter basis, and less than 25 mg per 100 kcal metaboliz-
cate protein quality (amino acid profile) or digestibility able energy. Actual analytical values must show that the product
(Chapter 5). consistently meets these levels. The estimation of magnesium
Crude fat refers to a specific analytical procedure that esti- content based on calculation from the guaranteed analyses must
mates the lipid content of a food obtained through either ether meet these criteria as well. The only exception occurs when the
extraction or acid hydrolysis. In addition to lipids, this proce- label bears an AAFCO calorie content statement that is higher
dure also isolates certain organic acids, oils, pigments, alcohols than would be estimated from the guaranteed analysis.
and fat-soluble vitamins. Because fats have more than twice the Ash consists of all noncombustible materials in the food,
energy density of proteins and carbohydrates, crude fat can be usually salt and other minerals. A high ash content in dry and
used to estimate the energy density of the food. If the moisture soft-moist foods generally indicates a high magnesium content.
and crude fiber content of two foods are somewhat similar, the However, the ash content of moist cat foods usually correlates
food with the higher crude fat guarantee will usually have the poorly with the magnesium content. Excessive magnesium
higher energy density. intake may be one risk factor for feline struvite urolithiasis
Crude fiber represents the organic residue that remains after (Chapter 43).