Chicken by-product in cat food is made from the parts of a chicken left over after the breast, thigh, and other cuts are removed for human consumption. That includes organs like the heart, liver, and gizzard, as well as heads, feet, and intestines. It does not include feathers, and it must be free of fecal content. While the ingredient list might sound unappetizing to you, many of these parts are nutrient-dense foods that cats would naturally eat in the wild.
What Parts Are Included
The Association of American Feed Control Officials (AAFCO), which sets the standard definitions for pet food labels, defines poultry by-products as “non-rendered clean parts of carcasses of slaughtered poultry such as heads, feet, viscera, free from fecal content and foreign matter.” In plain terms, that covers internal organs (liver, heart, gizzard, kidneys, lungs), the neck, head, feet, and intestines. If the label says “chicken by-product” specifically rather than just “poultry by-product,” all of those parts must come from chickens rather than a mix of different birds.
The giblets you find tucked inside a whole chicken at the grocery store, the heart, liver, and gizzard, are technically by-products. So when you see the term on a cat food label, it’s not exclusively the parts that sound off-putting. The composition varies from batch to batch, though, which is one reason the ingredient gets a mixed reputation.
Chicken By-Product vs. Chicken Meal
“Chicken by-product meal” and “chicken meal” are two different ingredients, and the distinction matters. Chicken meal is made from clean chicken flesh, skin, and bone that has been dried and ground into a concentrated powder. Chicken by-product meal is made from the organs, heads, feet, and other remnants after the desirable meat is removed. Both go through a rendering process where moisture and fat are cooked off, leaving a dry, protein-rich powder that’s easier to mix into kibble.
The key difference is consistency. Chicken meal draws from a narrower range of parts, so its nutritional profile stays relatively stable from one batch to the next. Chicken by-product meal can contain varying ratios of liver, feet, intestines, and other parts depending on what’s available, which means its protein quality and mineral content can shift. For this reason, many premium cat food brands use chicken meal or whole chicken as their primary protein and avoid by-product meal.
Nutritional Value for Cats
By-products are not nutritionally worthless. In fact, some of the organs they contain are among the most nutrient-rich parts of the animal. Chicken liver and heart are especially high in taurine, an amino acid that cats cannot produce on their own and must get from food. Research from UC Davis measured taurine levels in chicken heart and liver at roughly 1,100 to 1,180 milligrams per 100 grams of raw tissue, which is substantially higher than what you’d find in plain chicken breast. A taurine deficiency in cats can lead to serious heart and eye problems, so organ-rich ingredients can genuinely benefit your cat’s diet.
When rendered into a meal, chicken-based ingredients concentrate their protein significantly. Chicken meal, for example, contains about 67% protein on a dry matter basis, compared to roughly 42% in raw chicken (which carries far more water and fat). By-product meal typically falls in a similar protein range, though the exact number depends on which parts dominate a given batch. The tradeoff is a higher mineral (ash) content. Rendered chicken meal can contain around 16% ash compared to 6-8% in whole cooked chicken, largely because of the bone content. High ash levels aren’t harmful in normal amounts, but they dilute the percentage of usable protein and fat.
How By-Products Are Processed
Turning raw chicken parts into the dry meal that goes into kibble involves a process called rendering. The raw material is cooked at high temperatures, typically around 140°C (284°F), for roughly 45 minutes. This drives off moisture, separates fat from solids, and kills bacteria. The remaining dry material is then ground into a powder.
The heat does affect nutritional quality. Some amino acids, particularly lysine and cystine, start to break down if cooking goes on too long. Research on poultry by-product rendering found that these amino acids actually increase slightly in the first 40 to 60 minutes of processing, then decline with extended cooking. Manufacturers aim to hit the sweet spot that maximizes protein while minimizing nutrient loss, but the process is inherently less gentle than simply cooking fresh chicken.
Safety and Regulation
Pet food facilities that process animal by-products in the United States fall under FDA oversight through the Food Safety Modernization Act. Facilities must follow current good manufacturing practices, conduct hazard analyses, and implement preventive controls to ensure the final product is safe. If a human food plant supplies its by-products to a pet food manufacturer, it must at minimum prevent contamination during storage and transfer. If it further processes those by-products (drying, pelleting, heat-treating), it must comply with either human food or animal food safety standards.
In practice, this means by-products in commercial cat food go through regulated processing with temperature controls, contamination monitoring, and record-keeping requirements. The ingredient is not unregulated filler scraped off a slaughterhouse floor, though the vague-sounding name understandably makes people nervous.
Why It’s So Common in Cat Food
There’s a practical reason chicken by-products show up in so many cat foods: they use parts of the animal that would otherwise go to waste. When chicken breasts and thighs are processed for human grocery stores, enormous volumes of organs, heads, and feet are left over. Routing these into pet food keeps costs down for manufacturers and provides a protein source that, while variable, still meets the nutritional requirements cats need.
From an environmental standpoint, using by-products reduces the amount of animal material sent to landfills or incineration. Whether this makes by-product-heavy pet food “sustainable” is debatable, but it does mean the ingredient serves a function beyond simply being cheap.
Reading the Label
If you’re evaluating a cat food that contains chicken by-products, a few things are worth noting. First, check where the ingredient falls in the list. Ingredients are listed by weight before processing, so if “chicken by-product meal” is the first ingredient, it’s the primary protein source. Second, look for whether the label says “chicken by-product” or just “poultry by-product.” The chicken-specific version at least tells you which bird it came from, while the generic “poultry” label could include a mix of chicken, turkey, and other birds.
Third, consider what else is in the food. A cat food with chicken by-product meal alongside other named protein sources, added taurine, and limited fillers can still be a nutritionally complete diet. A food where by-product meal is the sole protein and is followed by several grain-based fillers is a different story. The presence of by-products alone doesn’t make a cat food good or bad. What matters is the overall formulation and whether it meets AAFCO’s nutritional adequacy standards, which will be stated somewhere on the packaging.