Animal Nutrition & Pet Food Ingredients Guide
- How to read a pet food label
Pet food labels are similar to the ones on the food you eat, in a few different ways. For one, the label lists the ingredients in descending order by weight. For another, they often contain a litany of words the average consumer doesn’t understand. Pet parents often balk at specific terms and descriptors, which alters the way manufacturers create food formulas. Here are two main ways a manufacturer can influence consumer perception of the ingredients in pet food.
Meat vs. meat meal
The most significant debate among pet food consumers today may be the question of meat versus meat meal. If given a choice with no context, most pet owners are likely to choose a pet food with meat as the first ingredient over food with meat meal as the first ingredient. They may not understand precisely what chicken, beef, or other meat meal is, but they have a vague concept that it’s not edible.
The Association of American Feed Control Officials defines meat meal as “the rendered product from mammal tissues.” Processors grind up skin, meat, and some bone, and extract most of the water content in a method called rendering. While chicken meal would never be in the running for family dinner, pets can often benefit more from the variety of nutrients found in the combination of parts than it could from a piece of chicken breast alone.
Foods containing meal as a first ingredient are often more nutritionally dense than those with just meat as the first ingredient. According to the United States Department of Agriculture, meat is mostly water. The muscle contains about 75 percent water by weight and 20 percent protein, with the remaining 5 percent comprised of carbs, minerals, and fats. A meat meal generally contains 10 percent water, resulting in a drastic shift in the nutrition-to-weight ratio.
The real question is the quality of the meat or meal in the food. It’s possible for a manufacturer to use fresh meat of poor quality just to say they’ve done so on the label.
By products are non-rendered parts of an animal, including feet, heads, and internal organs. A meat byproduct could contain a highly nutritious blend of hearts, livers, and a bit of bone, or it could all be waste material. There’s no way of telling by reading the label alone.
In general, the use of fresh meat in no way dictates the quality of pet food. It merely adds cost and forces the manufacturer to use other ingredients to make up for the nutrition lost to water weight.
The same consumers bent on avoiding meat meals also tend to look for foods with ingredients they perceive as healthy based on human standards. A cat and dog owner study by the Michelson Found Animals Foundation found 70 percent of people on a diet — like high-protein or organic — buy pet food that aligns with their food choices.
Many food labels feature beautiful spreads of fresh meats alongside fruits and veggies that offer little in the way of nutritional value for pets. Blueberries may look good on the cutting board next to fresh salmon chunks, but is it benefiting the dog or cat who will eat it in processed kibble form?
Most pet products that include whole foods in their formula list them near the bottom, after vitamins, minerals, and other crucial additives. At that point, you can be sure there are only a couple of grams of the ingredient in each pound of finished food. These ingredients serve little purpose outside of marketing.
- Proteins in pet food
Protein is the primary source of nutrition for cats and dogs. These essential nutrient blocks contribute to every facet of a pet’s development, from strong bones to cognitive function, healthy muscles, and a silky coat.
Proteins are made up of amino acids. These small molecules with similar but distinct structures come together to form different types of proteins. Of the 22 amino acids, dogs’ bodies produce 12 on their own. That means they must get sufficient quantities of the other 10 amino acids (called essential amino acids) from their food. Those 10 essential amino acids include Cats need the same 10 amino acids in their diet plus one more: taurine.
The best sources of protein
Not all protein holds the same value for pets. If the protein source is one the animal can’t digest well, the number of essential amino acids the animal can extract during digestion plummets. Corn gluten meal, for example, contains a significant amount of protein, at 65 percent by weight. You’d think it would be an excellent primary protein ingredient, but because cats can’t digest it fully, they would have to eat much more of it to get the same amount of protein they get from meat. While dogs have an easier time extracting nutrients from grains, meat-based protein is better for them. Many consumers are still firmly on the gluten-free pet food bandwagon for reasons they may not understand. In reality, too much gluten might make pets fat, but isn’t actively bad for them in general.
- The role of carbohydrates
Carbs get a bad rap in human diets, so it makes sense for consumers to shy away from them in pet food. That usually stems from the perception that dogs and cats don’t tolerate them well. It’s also common to bring up the fact that wolves and big cats in the wild “don’t raid cornfields” — so why are carbohydrates on so many pet food ingredients lists?
It’s true carbs are not a significant part of animal diets in the wild, but they serve an essential twofold function. Carbs serve as a source of energy to supplement the protein a pet receives in its diet. While not as digestible as meat, many forms of correctly processed carbs are relatively easy for both dogs and cats to digest. The most common carbs come from oats, corn, rice, and wheat.
For manufacturers and consumers, the benefits of carbs in pet food are mostly financial. Manufacturing the affordable dried kibble most people feed their pets requires carbohydrates to give it structure and shelf stability. Wet food, which doesn’t structurally need any carbs, often still contains some to keep the finished product affordable.
- Minerals and supplements in pet food
Ideally, we would all be able to feed our pets the rich, varied, meat-based diet they would get in nature — but that’s not realistic. Manufacturers must find ways to create the most nutritionally complete diet possible on a specific budget, so supplementing the main ingredients with isolated additives often make the most sense.
Dogs, cats, and even larger animals like horses share many of the same mineral needs, including the following:
- Calcium: You’ve likely heard about the importance of calcium since you were a kid, and it’s just as crucial for growing pets. This mineral builds strong bones, supports muscle contractions, and enables blood clotting. Almost 100 percent of calcium in humans and animals resides in the bones, which is why meat meal including bones can be such a good source of nutrients for pets.
- Magnesium: Magnesium is an all-purpose mineral, and has roles in many enzyme systems. Heart, liver, and muscle function rely on sufficient magnesium. It also helps store and retrieve energy within cells.
- Phosphorous: Phosphorus helps build cell membranes and nucleic acids. Together with calcium, it helps regulate energy production in the body. Phosphorus is a key part of calcium’s bone-building power, and comprises up to half of all bone material. Balanced levels of calcium and phosphorus are necessary to maintain healthy cell energy.
- Potassium: If you’ve ever suffered a charley horse, you’re aware of potassium’s importance. This mineral facilitates cell communication across membranes, helps balance the body’s fluids, and has a direct hand in healthy muscle function. Potassium is readily available in foods like carrots and peas, which are popular whole ingredients to include in pet food. It's not usually feasible to include enough whole food potassium sources, so supplementation is widespread.
- Sodium: Not only does sodium make a pet’s food taste more appealing, it’s responsible for regulating water retention in cells. With too much sodium, cells may dehydrate. Without enough, they take on too much water and sustain damage. A proper sodium balance also helps keep the nervous system and muscle cells in good shape.
- Trace elements in pet food
Balancing the minerals in supplements with the protein and carbohydrates from whole food sources is the key to formulating a successful pet food. Different animals have different nutritional needs, and most manufacturers serve a variety of species. Adding supplements to the formula allows a manufacturer to maintain a core of staple ingredients and adjust supplements to each species.
In addition to the macronutrients above, most pet foods contain trace elements:
- Copper: Copper plays a significant role in the formation of bodily structures like bone, collagen, and connective tissues. This element also helps form red blood cells and supports antioxidant functions in the body. Copper in pet food comes partially from whole grains and liver, but usually requires supplementation to ensure adequate levels.
- Iodine: Iodine facilitates thyroid function, and therefore is responsible for the production of hormones critical to metabolism and early life growth. It also keeps the digestive system healthy. Iodine is present in fish, but most food manufacturers supplement it with sodium iodide, potassium iodide, calcium iodate, or potassium iodate.
- Iron: Oxygen transfer is a critical function, and sufficient iron levels help ensure organs and muscles are getting all the oxygen they need. Iron comes primarily from meat sources, but also from some plants, including peas, soy, and green vegetables.
- Manganese: This essential mineral facilitates protein and carbohydrate usage in the body, and aids in energy production. Ingredients rich in manganese — such as grains, nuts, and green vegetables — don’t usually appear in sufficient amounts. Manganese supplementation is common in balanced pet foods.
- Selenium: Selenium is toxic when present in significant levels. In the minuscule amounts needed for function, selenium pairs with vitamin E to protect cells from oxidation. Because such small amounts of this mineral suffice for dogs and cats, supplementation of selenium hardly ever becomes necessary.
- Zinc: Zinc helps pets maintain healthy skin and a lustrous coat. It also supports reproductive health. This mineral is notably more difficult to absorb than most, and fiber can make it even less available to the body. Meat and bone carry significantly more zinc than plant sources, and pets fed diets high in grain are more susceptible to zinc deficiencies.
- Additives are essential in pet food
Additive ingredients in pet food are not a negative thing. In addition to the minerals necessary for happy, healthy pets, preservatives and antioxidants help ensure a quality food product. Pet food needs to last months in storage, and additives make the long shelf life possible.
Natural preservatives are the best choice for any pet food, as the most popular artificial ones — BHA, BHT, ethoxyquin, and propyl gallate — have links to chronic toxicity issues. Vitamin E, vitamin C, and rosemary oil are all natural preservatives with no known toxicity issues in pets. Adding one or more of these helps prevent the growth of mold and bacteria that can harm pets and cause food spoilage.
Additives also make food significantly more palatable for animals. Even high quality, nutrient-dense pet food doesn’t necessarily taste good, and a few flavoring additives can make the difference between a successful product and a well-formulated flop. From a marketing perspective, color additives can make for a highly distinct product without endangering pet health.