Chicken byproduct refers to the parts of a slaughtered chicken that don’t end up on your dinner plate: organs like the liver, heart, and gizzard, plus heads, feet, and other internal parts. You’ll see this term almost exclusively on pet food labels, where it’s a regulated ingredient with a specific legal definition. Despite its unappetizing name, chicken byproduct is a meaningful protein source, though its quality and composition can vary more than whole chicken or chicken meal.
What the Label Actually Means
The Association of American Feed Control Officials (AAFCO), which sets the standards for pet food labeling in the United States, defines poultry byproducts as “non-rendered clean parts of carcasses of slaughtered poultry, such as heads, feet and viscera, free from fecal content and foreign matter.” In practical terms, this includes giblets (heart, gizzard, liver), other internal organs, heads, feet, and sometimes undeveloped eggs.
The key word in the definition is “clean.” Fecal content and foreign matter are not permitted, except in the unavoidable trace amounts that come with large-scale processing. Feathers are not included in chicken byproduct. The ingredient must come from slaughtered poultry, not from animals that died of disease or other causes.
Chicken Byproduct vs. Chicken Meal
These two terms appear side by side on ingredient lists, but they describe different things. Chicken meal is a dry, rendered product made from chicken flesh and skin, sometimes with bone, but it specifically excludes heads, feet, and entrails. It’s cooked at high temperatures to remove moisture, leaving a concentrated powder with roughly 65% protein, 12% fat, and only about 10% water.
Chicken byproduct, by contrast, is not rendered the same way. It retains more moisture and isn’t as protein-dense, but it also keeps more of the original nutritional content of the organs intact. Think of chicken meal as a concentrated protein powder and chicken byproduct as closer to the raw ingredients themselves, just mixed together from parts you wouldn’t typically buy at a grocery store.
Nutritional Value of the Parts
The individual organs in chicken byproduct carry real nutritional weight. Liver and gizzard each contain around 17% protein, which is comparable to a raw pork chop and higher than duck meat. Heart comes in at about 14% protein, while intestinal parts and lung fall in the 11-12% range. Most of these parts have lower protein levels than whole chicken breast or beef, but they’re far from nutritionally empty.
Organ meats are also rich in essential amino acids, the building blocks of protein that animals need from their diet. Liver contains the highest levels of most essential amino acids among chicken byproducts, followed by gizzard and heart. In liver specifically, essential amino acids make up about 43% of total amino acids, a ratio similar to pork liver and only slightly below beef liver. The two most abundant essential amino acids across all these parts are leucine and lysine, both critical for muscle maintenance and immune function in dogs and cats.
The nutritional catch with chicken byproduct is variability. Because the definition allows such a broad mix of parts, one batch might be heavy on nutrient-rich liver and heart while another leans toward feet and heads, which contribute more collagen and minerals but less high-quality protein. You can’t tell from the label which parts dominate.
How Dogs Digest It
Research on Beagle dogs found that diets containing bone-based poultry byproduct meal at various inclusion levels (up to 24% of the diet) produced crude protein digestibility between 76% and 82%. Dogs on the highest inclusion level actually showed the best protein digestibility at about 82%, along with improved fat digestibility near 90%. That suggests the protein in these byproducts is reasonably bioavailable for dogs, not just filler passing through the system.
Feather meal, which is a separate byproduct not typically found in standard “chicken byproduct” listings, performed differently. It slightly reduced overall digestibility compared to the control diet, reinforcing why feathers are processed and labeled separately from organ-based byproducts.
How Byproducts Are Processed
When chicken byproducts are further processed into “chicken byproduct meal” (the dried version), they go through rendering. The raw materials are first ground, then cooked in steam cookers at temperatures between 245°F and 290°F for 40 to 90 minutes. This heat treatment kills bacteria, viruses, parasites, and other pathogens. After cooking, the material is pressed to separate fat from solids, the fat is cleaned through centrifuging, and the remaining protein solids are dried and milled into a powder.
The FDA requires that all pet foods, including those containing byproducts, be safe, produced under sanitary conditions, free of harmful substances, and truthfully labeled. Canned pet foods specifically must undergo processing that eliminates viable microorganisms. FDA and state regulators conduct risk-based inspections of manufacturing facilities to verify compliance.
Why It Exists in Pet Food
Chicken byproducts exist because the poultry industry produces enormous volumes of parts that American consumers don’t want. In many parts of Asia and other regions, organs and feet are common in human cooking. But in Western markets, these parts are directed toward pet food, animal feed, pharmaceuticals, and cosmetics instead.
For pet food manufacturers, byproducts are a cost-effective protein source. They’re cheaper than whole chicken breast or thigh meat, which lets companies hit protein targets at lower price points. This is why you’ll see chicken byproduct more often in budget and mid-tier pet foods, while premium brands tend to use named muscle meats or chicken meal and highlight the distinction on their packaging.
The presence of chicken byproduct on an ingredient list isn’t inherently a red flag. Organ meats like liver and heart are nutritionally valuable, and many veterinary nutritionists consider them perfectly appropriate ingredients. The concern is more about consistency and transparency: because the definition is broad, you’re trusting the manufacturer to use a quality mix of parts. If the label says “chicken” or “deboned chicken” as the first ingredient, you know you’re getting primarily muscle meat. With “chicken byproduct,” you’re getting a less predictable combination.