Nutritional Needs of Cats and Dogs: By-products vs Meals
A common ingredient in many commercial pet foods is meat by-product meal. By-product meal is not the same as meat meal. The Association of American Feed Control Officers (AAFCO) is the governing body of pet food in North America. By their definition, meat by-product meal “consists of the ground, rendered clean parts of the carcasses of slaughtered meat such as necks, feet, undeveloped eggs, intestines, lungs, spleen, kidneys, brain, livers, blood, bone, fatty tissue, and stomachs, exclusive of feathers, hair, horns, teeth, and hooves.” Popular meat by-products are beef, chicken, and lamb. Meat by-product meals are high contain a high percentage of protein, although can be variable due to the variety of meats within the meal. This definition varies greatly from that of “meat meal,” which reads “the dry rendered product from a combination of clean flesh and skin with or without accompanying bone, derived from the parts or whole carcasses of meat or a combination thereof, exclusive of feathers, hair, heads, feet, entrails.” This means that meat meal contains only the flesh and skin, with or without the bone. As a result, it generally consists of a higher protein concentration than meat by-product meal. To ensure that pets are receiving the highest source of natural protein, read the ingredients on the food packaging to ensure the first ingredient (or two) are high-grade sources of animal protein, not grains or other carbohydrates.
Common sources of meat meal (see above for AAFCO definition) are beef, chicken, lamb, and fish. They come from meats consisting of rendered animal flesh. A quality grade meat meal can actually be a better source of protein than the whole meat from which it was made. This is because meat meal removes the moisture, leaving a highly concentrated source of protein. This means that if measured in equal weight (kg), cats and dogs get more protein from the meat meal than if they were to eat the same quantity (kg) of meat whole.
The marketplace can be misleading when it comes to pet food labels. The first ingredient on a bag of kibble is the highest inclusion by weight PRIOR to cooking; like the recipe for a cake. Here’s an example will help explain why this is important. Dog food is made in a very similar process to many human foods, such as cereals. All the ingredients are mixed together, slowly cooked using steam and temperature, dried, and then the fats are added. Kibble tends to have a moisture content of ~10%. If you think about it, using whole fresh meat and running it through this process ultimately turns it into meat meal.
Now here’s the catch. Let’s say a manufacturer of kibble has chicken as the first ingredient on its label. And let’s say they add 400 kg/ton of chicken to their food. That chicken, although by weight at the time of inclusion (PRIOR to cooking) is the primary ingredient, now gets dried down to 10% moisture like the rest of the kibble, what is happening to the weight of that chicken once it is dried? With the water gone, the weight of that chicken is now greatly reduced, and it is likely no longer the first ingredient in that product. If chicken meal was the first ingredient, given that it is already dried to 10% before it goes into the manufacturing process, will not dry down any further, therefore it will remain the first ingredient on the label and the primary protein source. Using fresh chicken in combination with vegetable proteins as even the 3rd or 4th ingredients can mean your meat in not the largest protein contributor.