By-product meal in dog food is a dry, ground powder made from animal parts that aren’t sold as conventional cuts of meat. These include organs like liver, kidneys, and heart, along with bones, intestines, and other tissues left over after the muscle meat is removed for human consumption. Despite its unappealing name, by-product meal is a concentrated source of protein and nutrients, and its composition is regulated by feed control standards.
What’s Actually in By-Product Meal
The specific parts depend on whether the ingredient comes from mammals or poultry, and the official definitions are set by the Association of American Feed Control Officials (AAFCO), which standardizes pet food labeling in the U.S.
Meat by-products (from mammals like cattle, pigs, or sheep) include lungs, spleen, kidneys, brain, liver, blood, bone, low-temperature fatty tissue, and stomachs and intestines that have been cleaned of their contents. Hair, horns, teeth, and hooves are explicitly excluded.
Poultry by-product meal consists of ground, rendered parts from slaughtered poultry: necks, feet, undeveloped eggs, intestines, and internal organs including the heart, gizzard, and liver. Feathers are excluded, except in trace amounts that are unavoidable during processing.
There’s also animal by-product meal, a broader category from mammal tissues that excludes added hair, hoof, horn, hide trimmings, manure, and stomach contents. The word “meal” in any of these names means the ingredient has been cooked down (rendered) and dried into a powder, which concentrates the protein content significantly compared to raw meat that contains 60 to 70 percent water.
How Rendering Works
Rendering is the cooking process that transforms raw animal tissues into a shelf-stable, dry ingredient. The raw materials are heated at high temperatures for extended periods, which accomplishes two things: it drives off moisture to create a concentrated powder, and it eliminates bacteria, viruses, and other biological hazards. Rendered products are considered safe from pathogens because the cooking temperatures and durations exceed what’s needed for basic food safety.
The tradeoff is that intense heat processing can reduce nutrient quality. Research published in the Journal of Animal Science found that chicken meal, which undergoes full rendering, had lower digestibility for most essential amino acids compared to less processed chicken. For example, the digestibility of lysine (a key amino acid for dogs) was about 79% in chicken meal versus 87% in raw chicken. Methionine digestibility dropped from about 93% in raw chicken to 86% in the rendered meal. These differences are meaningful but not dramatic, and steamed chicken actually outperformed raw chicken in digestibility scores, suggesting that some processing can help while heavy processing reduces quality.
Protein Quality and Digestibility
Not all by-product meals are nutritionally equal. The protein content and how well dogs can actually absorb it varies depending on the source animal and how the ingredient was processed.
Poultry-based meals tend to perform better than mammal-based ones. Research measuring actual protein digestibility in dogs found that poultry meals averaged about 85% digestibility, with individual samples ranging from 80% to 89%. Meat and bone meal from mammals averaged around 76%, with a tighter range of 73% to 79%. The protein content itself also differs: poultry meals tested between 57% and 69% protein by dry weight, while meat and bone meals came in at 39% to 46%.
For context, these digestibility numbers are respectable but below what you’d see from whole muscle meat or gently cooked animal proteins. A dog eating food with poultry by-product meal as the main protein source is absorbing the large majority of that protein, but a food built around fresh or lightly processed meat will deliver slightly more usable nutrition per gram.
By-Product Meal vs. Named Meat Meal
On a dog food label, you’ll see several variations that sound similar but differ in important ways. “Chicken meal” is rendered from chicken muscle tissue and skin, with or without bone. “Chicken by-product meal” comes from the non-muscle parts: organs, necks, feet, and intestines. “Poultry by-product meal” is the same concept but can come from any poultry species, not just chicken.
The word “by-product” doesn’t mean the ingredient is nutritionally inferior across the board. Organ meats like liver and kidney are nutrient-dense, packed with vitamins A and B12, iron, and other minerals that muscle meat lacks. The concern with by-product meals is consistency. Because the definition allows a range of parts, the exact nutritional profile can shift from batch to batch depending on the ratio of organs to bones to connective tissue. A batch heavy in liver and heart is nutritionally different from one that’s mostly necks and feet.
Named meat meals (like “chicken meal” or “lamb meal”) tend to have a more predictable composition because they’re sourced from a narrower set of tissues. That said, a well-made by-product meal from a reputable manufacturer can be perfectly nutritious, while a poorly sourced “chicken meal” from a lower-quality supplier may not be much better.
Why It Appears in So Many Dog Foods
By-product meal is one of the most common protein ingredients in commercial dog food for practical reasons. It’s significantly cheaper than whole meat or named meat meals because it uses parts of the animal that have limited demand in human food markets. It’s also extremely protein-dense in its dried form, which makes it efficient for meeting the protein requirements on a nutrition label.
Premium and veterinary-diet brands use by-product meals regularly, which surprises many pet owners who associate the ingredient with low-quality food. The reason is straightforward: organ meats provide a nutrient profile that muscle meat alone doesn’t, and the rendered meal format is stable, safe, and easy to incorporate into kibble manufacturing. Price is certainly a factor, but it’s not the only one.
How to Evaluate It on a Label
If you’re reading a dog food ingredient list and see a by-product meal, a few details can help you gauge quality. First, look for a named species. “Chicken by-product meal” or “turkey by-product meal” tells you the source animal, while generic “poultry by-product meal” or “animal by-product meal” leaves it vague and allows the manufacturer to shift between species depending on what’s available. Named sources generally indicate tighter quality control.
Second, consider where it falls in the ingredient list. Ingredients are listed by weight before processing, so a by-product meal in the first three positions is a primary protein source in that food. If it appears further down, it’s contributing less to the overall nutrition.
Third, look at the guaranteed analysis panel for minimum protein percentage and consider the brand’s reputation for sourcing transparency. Two foods can both list “poultry by-product meal” and deliver meaningfully different nutrition depending on how that meal was sourced and processed. Brands that publish digestibility data or third-party testing results give you more confidence in what’s actually in the bag.