Assuming this content is correct, it sounds fairly harmless.
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http://www.ehow.com/about_5118687_purpo ... -feed.html)
Purpose of Ash in Animal Feed
By Bethney Foster
Almost all pet foods contain ash. However, the ash in dog and cat food is not the same substance as the ash you would find in your fireplace. The ash in pet food is a measurement of the
minerals needed by your pet for its body to function properly. The measurement of ash you see on the label of your pet's food is part of the nutritional analysis of the product. Many pet foods contain up to 14 percent ash, which for most pets is not a concern.
Definition
Ash is what remains after food is heated at high temperatures. When pet food is completely incinerated, protein, fat and carbohydrates burn away, leaving behind only the food's minerals, which include calcium, phosphorus, zinc, iron and many others.
These minerals are the food's ash content, which is just a way of describing the mineral content of the pet food.
Processing
Ash is created when pet food is heated to temperatures somewhere between 550 and 600 degrees F and
cooked at this temperature for about two hours. This process burns off all the organic parts of the pet food,
leaving behind only the inorganic parts. "If the mineral content of pet food sounds high," pet food nutritionist Kim Russell wrote in New Scientist magazine, "it is important to remember that
our domestic carnivores were designed to eat carcasses that are full of bones containing minerals, and a well-designed pet food will reflect this in its composition."
Minerals
The
minerals contained in ash include calcium, iron, magnesium, sodium and zinc, along with trace amounts of many others. At one time, pet food manufacturers often raised the mineral content of their foods by adding bone meal. However, concerns about Bovine Spongiform Encephalopathy, or mad cow disease, have changed this practice. Most producers now use fish meal instead.
Need for Minerals
Pets need the contents of ash, or the minerals it contains, for proper bone and tissue development and for their bodies to function properly. It's important to ensure your pet's food has the correct mineral level and that you are feeding your pet a product certified by a nutritionist and produced by a trust-worthy manufacturer. If your pet's diet is too low in ash, your companion may not be getting the minerals it needs, which could lead to a mineral deficiency and cause health problems for your dog or cat.
How Much
The content of ash in pet foods usually ranges between 5 and 8 percent, but can go as high as 14 percent in dry foods. Canned foods generally have about half that amount. While it's important that pets get the appropriate levels of minerals for optimum health, some parts of ash content---namely magnesium---may contribute to urinary crystals in susceptible cats and dogs.
