Re: dry vs wet PF:
http://www.api4animals.org/facts.php?p=359&more=1Dry Food
"The vast majority of dry food is made with a machine called an extruder. First, materials are blended in accordance with a recipe created with the help of computer programs that provide the nutrient content of each proposed ingredient. For instance, corn gluten meal has more protein than wheat flour.
Because the extruder needs a consistent amount of starch and low moisture to work properly, dry ingredients — such as rendered meat-and-bone-meal, poultry by-product meal, grains, and flours — predominate."The dough is fed into the screws of an extruder. It is subjected to steam and high pressure as it is pushed through dies that determine the shape of the final product, much like the nozzles used in cake decorating. As the hot, pressurized dough exits the extruder, it is cut by a set of rapidly whirling knives into tiny pieces. As the dough reaches normal air pressure, it expands or “puffs” into its final shape. The food is allowed to dry, and then is usually sprayed with fat, digests, or other compounds to make it more palatable. When it is cooled, it can be bagged.
"Although the cooking process kills bacteria in the ingredients, the final product can pick up more bacteria during the subsequent drying, coating, and packaging process. Some experts warn that getting dry food wet can allow the bacteria on the surface to multiply and make pets sick. Do not mix dry food with water, milk, canned food, or other liquids.
"A few dog foods are baked at high temperatures (over 500°F) rather than extruded. This produces a sheet of dense, crunchy material that is then broken into irregular chunks, much like crumbling crackers into soup. It is relatively palatable without the sprayed-on fats and other enhancers needed on extruded dry food.
"Semi-moist foods and many pet treats are also made with an extruder. To be appealing to consumers and to keep their texture, they contain many additives, colorings, and preservatives; they are not a good choice for a pet’s primary diet.
Wet Food
"Wet or canned food begins with ground ingredients mixed with additives. If chunks are required, a special extruder forms them. Then the mixture is cooked and canned. The sealed cans are then put into containers resembling pressure cookers and commercial sterilization takes place. Some manufacturers cook the food right in the can.
"Wet foods are quite different in content from dry or semi-moist foods.
While many canned foods contain by-products of various sorts, they are “fresh” and not rendered or processed (although they are often frozen for transport and storage). Wet foods usually contain much more protein, and it’s often a little higher quality, than dry foods. They also have more moisture, which is better for cats. They are packaged in cans or pouches."
So basically it's the way some dry food and semi-moist is made which brings the rendered meats into the picture. I use FRR and that's baked at high temps. The pieces are irregular, as if you broke a cookie; no rendered meats or by products in FRR.
The link below is interesting as it also tells what happened to the inedible fats that used to be used for soap:
http://en.wikipedia.org/wiki/Rendering_(food_processing)
"In the early 20th century the low cost of synthesis of artificial nitrogen fertilizers undermined the economic use of animal waste to enrich soils. This resulted in the loss of a substantial market for meat by-product solids.
But this lost market was replaced by the realisation that these products made good feed for animals. After World War II synthetic detergents came on the scene which eventually displaced soaps for both domestic and industrial washing uses.
Thus, in the early 1950s over 50% of the inedible fat market disappeared. Diversion in these materials into animal feeds soon replaced the lost soap market and eventually became the single largest use for inedible fats."So the recalled beef is not allowed to go
directly into pet food as meat, but it
can go in there
indirectly through rendering.
If you are using a dry food, any labeled as Kosher would be free from the rendered material as above, because it would be impossible to say that the renderings did not contain non-Kosher animal by products. AFAIK, Evanger's is certified Kosher--know this is true for their canned products, and am assuming it's also so for their dry.
