The good grains and vegetable content

Corn Gluten Meal as second or lower ingredient:
As I am continually providing information on this subject, I have decided it is best to record it here so that it is readily accessible at any time for those who care to have their facts straight.
  • Anyone with training in food chemistry will be able to tell you that the term "gluten" refers to the protein content of corn. The information is backed up on many sites online. The difficulty with corn gluten meal is that it doesn't contain all the amino acids needed by felines, so you definitely need to have muscle meat protein "meal" as a higher protein source than the corn. Remember that "meal" is dry weight and not mostly water.
  • At Ingredients 101, there is a breakdown of corn as a commercial ingredient sold for livestock feed. While the protein content there is estimated to be 60%, I have found higher percentages provided online by government inspected enterprises.
  • One often finds comments about corn gluten meal being "useless" to felines, however, the prestigious PubMed site shows a study regarding feline assimilation of corn gluten meal where it was found to be 2.5% less bioavailable than chicken meal. In that paragraph, on the third line, click on Table III to confirm the following figures:
    meat meal - 83.3%
    chicken meal - 80.2%
    corn gluten meal 77.7%
  • In the above study, in Table IV, the absorption and retention of nitrogen from those figures were slightly more realistic in representation, in that actual nitrogen retention with the remainder being excreted in either urine, or feces was:
    meat meal - 18.3 ± 4.4
    chicken meal - 13.1 ± 4.6
    corn gluten meal - 11.8 ± 7.3
  • In the above study, under "Diet", Table II also breaks down amino acid content of corn gluten meal as compared to meat meal and chicken meal. Corn gluten meal contained as much of the sulphur amino acids, (methionine and cystine), as the other two, whereas other grain and vegetables are lacking in these amino acids. The importance of this is in the development of struvite crystals. Sulphur amino acids are needed to provide an acid pH that will prevent crystal development.
  • Corn gluten is used as a germination retardent , which is used for sensationalism by those who have an agenda, that has nothing to do with corn gluten meal's capability of safely supplying nutrition to our companion animals. The safety of the ingredient is reflected in the fact that it cannot harm living organisms, and in fact, as it breaks down, becomes a high nitrogen fertilizer because of the protein content.
The next two products are discussed at a site that reflects some of the recent research done on fermentable fibres for felines done by Sunvold and Reinhart. You may notice in Table 6 that both acceptable fibre sources are moderately fermentable, and have low solubility. This article is a composite of other papers presented at different times to their peers.
Rice Bran:
Rice bran is the outside layer of the rice kernel, which contains the bran, and part of the rice germ. It is the part of the rice kernel that is removed to make brown rice. The first URL, and this one, take you to nutritional breakdowns of the product.
Beet Pulp:
Beet pulp is the other, more commonly used fermentable fibre with low solubility, and moderate fermantability, as recommended in the Reinhart and Sunvold paper presented to the 1996 Iams Symposium. It is the vegetable matter, which remains after sugar is extracted from sliced sugar beets.
Some interesting studies on this subject can be found here, here, and references are made in the National Research Council, (2006) book on Nutrient Requirements of Dogs and Cats Page 38 of these notes from the Iam's symposium states, "Fiber digestibility was greatest for cats consuming a diet containing beet pulp (a moderately fermentable fiber), a diet containing the highly fermentable blend of fibers and a diet containing a combination blend of fibers designed to provide moderate fermentation (beet pulp, rice bran, citrus pectin, and carob bean gum)"