By-product meal

What 'by-product meal' actually contains

AAFCO defines meat by-product as the non-rendered, clean parts of slaughtered mammals other than meat. By-product meal is that material rendered, cooked under pressure to drive off water and fat, leaving a shelf-stable powder roughly 60–70% protein. It must not include hair, horn, hide trimmings, manure, or stomach contents.

Common species-specific versions include chicken by-product meal and beef by-product meal. The 'meal' designation matters: it is concentrated, so it ranks higher on the ingredient list per gram of protein delivered than fresh muscle meat, which is roughly 70% water.

Nutritional value

Organ meats in by-product meal are nutrient-dense: liver carries iron, vitamin A, and B-vitamins; heart is a rich natural source of taurine; kidney delivers selenium. For an obligate carnivore like a cat, organ content is not filler, it more closely matches the prey-model diet than muscle meat alone.

Digestibility varies by manufacturer. Reputable producers test apparent digestibility and report it on request; that number, not the ingredient name, is the meaningful quality signal.

Why owners worry about it

Marketing in the premium-food category has spent two decades framing by-products as low-quality. Veterinary nutritionists generally disagree: WSAVA's guidance treats by-product meal as a legitimate ingredient when sourced from a manufacturer with quality control. The label tells you what category of material is in the bag; it does not tell you the supplier's standards.

Why it matters

Avoiding by-product meal on principle can push owners toward boutique brands with weaker nutritional programs. The better question is not 'does this food contain by-products?' but 'does this manufacturer employ a veterinary nutritionist, run feeding trials, and publish digestibility data?'