Ash & Magnesium surrounded by can cat foods.?

What is a safe level in cat's can foods as far as Ash & the Magnesium levels? I went to several sites, but need more info. I hear adjectives dry is no good or wet food as well. My cat get a 50 -50 combo of Dry & canned foods both Grain - Free. Drinks a moderate amount of Water. Thanks Yahoo Answers.
Answers:    I tried finding a vet or government site with info on ash and magnesium, but didn't enjoy much luck. However I did locate some info that is reliable.

Ash - The total of all minerals contained within a particular food. This term is used to describe the residue left by such minerals after the food have been burned (which is the way food is tested for ash).

Magnesium - A required nutrient. It is important surrounded by sodium and potassium metabolism, enzyme reactions and the proper functioning of muscles and nerves. It is found in the soft
tissues of the body as well as within bones. Sources of magnesium included bone meal, poultry by-product meal, whole grain, green vegtables, and dairy products.
I did find this over on a Mulligan Stew pet food site, which helps. It talks about the trait of protein versus the 'ash'

You will be relieved to know that ash is not added to pet foods. It is a way of describing the maximum mineral content of pet food. The ash you see listed is part of a "Guaranteed Analysis" statement to be exact required by the Association of American Feed Control Officials (AAFCO). According to AAFCO, besides the Ash (max), a pet food label must also list the following guarantees; protein (min), crude fat (min), crude fiber (max) and moisture (max).

Ash is measured by heat a sample of the pet food to temperatures of around 550 ∞C, and burning off adjectives the organic components to leave just the inorganic residue. Thus, ash is not added as an ingredient but is instead an indicator of mineral content. These minerals will be mainly potassium and phosphorus with smaller amounts of calcium, iron, magnesium, sodium and zinc, and trace amounts of many others.

Consumers can analyze the actual mineral content in Mulligan Stew Pet Food by visit our website. As part of our Formulation Guarantee program, we post a nutritional analysis from an independent laboratory for each batch of Mulligan Stew Pet Food. The nutritioanal analysis will show the actual trace minerals found contained by our pet food, including potassium and phosphorus.

The amount of Ash in a pet food may provide some indication of the quality of the protein being utilized surrounded by the food. Generally, the lesser the Ash content the higher the quality of the protein source. Lower element proteins such as "meals" (i.e.chicken meal) and "meat by-products" contain higher levels of bone and even feathers, both of which contribute to higher mineral level and thus higher Ash content. Some manufacturers have Ash level as high as 15%. Mulligan Stew Pet Food contain high quality proteins, no meal or by-products are ever used. The Ash content in our products is typically no higher than 2.8%.

An all drizzly food diet is preferable if you are able to do it. I assume you are concerned about ash and magnesium for the urinary tract robustness of your cat. The theory that ash and magnesium contribute to FLUTD is outdated.
Label claims to prevent or reduce the risk of FLUTD, cystitis, urinary problems or similar verbiage are drug claims and are not allowed underneath the law. However, in an effort to find some meaningful health-related information to the consumer, CVM is exercising regulatory discretion in not taking action against products that tolerate claims akin to "reduce urine pH to help maintain urinary tract health" or to own low magnesium levels. With respect to urine pH claims, this discretion is contingent upon adequate controlled studies to demonstrate that consumption of the product results in an appropriately sharp urine. Since too much acidification of the urine can also result in serious health problems, data to demonstrate safekeeping of the product are reviewed as well. With respect to dietary magnesium levels, the "cut-off" criteria to support a "low magnesium" claim are less than 0.12% on a dry business basis and less than 25 mg per 100 kilocalories of metabolizable energy. Companies submit the results of proximate analyses (including crude protein, crude obese, crude fiber, moisture, and ash) and magnesium analyses of a number of production runs of the product. Demonstration that the product formulation consistently meets the cut-off criteria supports the label claim. The estimation of magnesium content as calculated by using guaranteed analysis values on the product sticky label must also meet the criteria.

In order to be most useful surrounded by reducing the risk of FLUTD, products must also be used correctly. If the product is mixed with other foods or "meal fed" (offered for only a short spell of time per day), it might not be able to maintain the proper urine pH to be beneficial. Thus, feed directions are added to recommend the product be fed alone and to be made available throughout the day. Also, the nutritional adequacy statement on the sticky label must be for adult maintenance only. This disease occur primarily in young to middle-aged adults, and the most serious problems occur within males. Since the safety of these products for kittens and pregnant or nursing queens has not been established, it is recommended not to use these products for these duration stages.

Another FLUTD-related claim, "low ash," is not allowed on cat food labels. The current scientific consensus is that ash per se is not related to the incidence of FLUTD. There are no valid reason to reference ash on the product label (other than in the guaranteed analysis) apart from in regard to this outdated theory. Thus, "low ash" or similar claims, even short reference to FLUTD, are inherently false and misleading, which render the product misbranded and subject to regulatory action.
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