Nutrition

By-products are one of the most misunderstood pet-food ingredients. Public perception, often shaped by marketing that explicitly contrasts 'no by-products' against 'with by-products', frames the term as meaning 'beaks, feet, hooves, intestinal contents'. The actual AAFCO regulatory definition is clean meat from animals other than skeletal muscle — typically organs (liver, kidney, heart, spleen, lung) and other clean parts. Organ meats are nutritionally dense, with high concentrations of vitamins (A, B12, riboflavin, niacin, folate), minerals (iron, zinc, copper, selenium), and high-quality protein. The article explains the regulatory definition, what is actually in 'chicken by-product meal', why the marketing framing is misleading, and how to read by-product mentions on labels.