Nutro vs. Ziwi Peak

Bone broth is considered a controversial ingredient because the animal source is not identified.

Iron oxide is an FDA approved natural food coloring agent. It's commonly found in rusting metal and provides a reddish-brown color.

We believe food colorants are unnecessary ingredients in pet food. Other than potential harm, food colorants do not provide any nutritional value. These type of ingredients are used only to make the food look appealing to humans.

Pea protein is produced by removing the starchy parts of peas. Pea protein is considered controversial because it provides a substantial plant based protein boost. This boost is undesirable because plant based protein is typically lower in biological value when compared to meat based proteins.

Pork plasma is the colorless fluid part of a pig's blood. It may sound disgusting, but it's actually very nutritious for pets. Regardless of the nutritional aspects, consumers are shocked by this ingredient, which is why pork plasma is considered a controversial ingredient.

Whole wheat is one type of whole grain and contains the entire grain of wheat (the germ, bran, and endosperm). Wheat is regarded as an inexpensive and low-quality filler in pet food. However, wheat does provide plant-based protein and makes pet food more affordable for consumers. It's important to note that plant based protein does not provide the same amino acid profile as meat based protein.

Brewer's rice is the small fragments of rice kernel that are separated from the larger kernels of milled rice. The fragments do not contain the same nutrition profile of the whole kernel and therefore brewer's rice is a lower quality grain. Brewer's rice is typically regarded as an inexpensive and low quality filler.

Wheat gluten is the main protein of wheat. Although wheat gluten is mostly protein, wheat gluten is considered controversial because it significantly boosts the protein content of the product. This is undesirable because plant based protein does not provide the same amino acid profile as meat based protein.

Animal plasma can be a nutritious addition to pet food, however, the source should be specified. In this case, the animal source is not specified and therefore we cannot determine which animal was used to obtain the plasma.

Caramel color is a concentrated form of caramel, a natural food colorant. Caramel color has been linked to cancer in laboratory animals. Since our pets do not care about food color, caramel color is an unnecessary addition with possible health risks.

Tomato pomace is a by-product of tomato manufacturing. It's considered a controversial ingredient because many people believe it is an inexpensive low quality filler. However, tomato pomace provides a notable amount of dietary fiber, B vitamins, Lycopene, and vitamin A. Although it is a very inexpensive ingredient, it is not nutritionally empty.

Specific vegetable oils are typically positive ingredients; however, this ingredient does not specify which vegetable(s) were used to produce the oil.

Without this information, it is impossible for us to make any specific statements. With any fat source, it is important to know the omega-3 to omega-6 fatty acid ratio, a property which cannot be determined with this ingredient. Thus, we have marked vegetable oil as a controversial ingredient.

According to AAFCO, feeding oatmeal "is obtained in the manufacture of rolled oat groats or rolled oats". It contains "broken oat groats, oat groat chips, and floury portions of the oat groats." In other words, feeding oatmeal is an inexpensive by-products of rolled oat processing.

Corn syrup is made from corn starch and it's typically used as a thickener, sweetener, and humectant (keeps the product moist). It's considered controversial because it can raise a pet's blood sugar to unhealthy levels. Of course this concern may be nullified if the syrup is used in very small quantities.

Powdered cellulose is produced from minuscule pieces of wood pulp and plant fibers. Other than its fiber content, powdered cellulose lacks any nutritional contribution.

Dried tomato pomace is a by-product of tomato manufacturing. It's considered a controversial ingredient because many people believe it is an inexpensive low quality filler. However, tomato pomace provides a notable amount of dietary fiber, B vitamins, Lycopene, and vitamin A. Although it is a very inexpensive ingredient, it is not nutritionally empty.

Pea protein isolate is produced by removing the starchy parts of peas. Pea protein isolate is considered controversial because it provides a substantial plant based protein boost. This boost is undesirable because plant based protein is typically lower in biological value when compared to meat based proteins.

Canola oil is a plant-derived oil from the seeds of canola plants. Although fat is an essential component of any diet, canola oil is controversial in pet food. Proponents claim that canola oil provides a better fat profile in comparison to other plant based oils. However, opponents claim that canola oil is typically produced with genetically modified rapeseed and that rapeseed oil has multiple adverse health affects.

Lamb plasma is the colorless fluid part of a lamb's blood. It may sound disgusting, but it's actually very nutritious for pets. Regardless of the nutritional aspects, consumers are shocked by this ingredient, which is why lamb plasma is considered a controversial ingredient.

Menadione sodium bisulfite complex is a synthetic version of vitamin K that has been linked to many health concerns. Research has suggested possible toxic reactions in liver cells and red blood cells among other serious problems. In fact, one large chemical supplier warns, "The substance is toxic to kidneys, lungs, liver, mucous membranes. Repeated or prolonged exposure to the substance can produce target organs damage."