Corn Protein Meal in dog and cat food

Is it OK for dogs and cats?

Dogs

Corn protein meal is the same ingredient as corn gluten meal under a new name. The sources reviewed report no harm to dogs from it. It is low in lysine, so complete foods pair it with other proteins or added amino acids.

Cats

No harm from the ingredient itself is reported for cats. In one small cat study, a diet based on it (under its older name) was digested slightly less well than a chicken meal diet, and the authors preferred chicken meal. On its own it is short of lysine and arginine for cats, so complete foods combine it with other proteins.

How settled this is: No known concern at the amounts used in complete foods

What corn protein meal is

Corn protein meal and corn gluten meal are two names for the same ingredient. AAFCO's Ingredient Definitions Committee proposed the new name in 2022. Its minutes say "gluten" was historically a general word for plant protein, which now causes confusion because the protein in corn differs from the gluten protein in wheat. In January 2024, AAFCO's members made the definition official under the name "Corn Gluten Meal (Corn Protein Meal)", with the "gluten" name set to be removed in 2025. In April 2024, an attempt to revive a motion delaying that date failed. The committee referred industry concerns to AAFCO's Enforcement Issues Committee, to decide whether a period of enforcement discretion is needed. Labels can take time to change, so you may see either name. The ingredient is what remains of corn after most of the starch and germ have been removed and the bran separated off. This happens during wet milling for starch or syrup, or through enzyme treatment of the endosperm. The EU Catalogue of feed materials lists the equivalent material as "maize protein" and accepts "maize gluten" as a synonym. It describes the material as mainly protein (prolamins) separated out during maize starch manufacture, and EU rules allow "maize" to be called "corn".

Why it is in pet food

It puts a lot of protein into a small amount of ingredient. One sample analysed in 2021 held 67.5% crude protein on a dry-matter basis. Its amino acids complement those of soy. Corn protein is high in methionine and leucine but low in lysine, while soy ingredients are richer in lysine and lower in the sulfur amino acids. The researchers concluded that it has nutritional value in dog and cat diets. They added that complementary proteins or supplemental amino acids are needed to meet all essential amino acid requirements.

What it does in the food

A protein ingredient. In a 2021 analysis (under the name corn gluten meal, dry-matter basis) it held 67.5% crude protein, 9.1% fat, 1.75% methionine, 1.25% lysine and 11.0% leucine. In a cecectomized rooster assay, standardized digestibility was 93% or higher for every essential amino acid except lysine (81.8%). Against AAFCO adult maintenance values, lysine was the first-limiting amino acid for both dogs and cats. For cats, arginine and tryptophan also scored below 100%.

Safety and limits

The sources reviewed report no harm from this ingredient itself in dogs or cats. The research below was published under its older name, corn gluten meal. Cats: one study fed 12 adult cats dry diets in 3-week periods. The diet using it as the main protein had lower dry-matter digestibility (77.7%) than diets based on chicken meal (80.2%) or meat meal (83.3%). Nitrogen absorption was similar to the chicken meal diet, and urine was less alkaline with fewer struvite crystals. The authors concluded that chicken meal was better than or equal to it for adult cat food. They added that extra arginine would be needed if it were the only protein source. Dogs and cats: the amino acid figures come from a laboratory assay in roosters, not from feeding trials in dogs or cats. The authors note that results from this assay have matched those from dogs, but that it has not been fully established as a model for cats. That study was supported by an ingredient supplier, which also provided the samples. Contaminants: FDA's 2021 aflatoxin survey targeted dog and cat foods made with corn or corn by-products, including corn gluten. All but one of the foods were dry kibble. None of the 200 foods tested exceeded FDA's action level of 20 ppb for dog and cat foods. FDA traced the aflatoxin in the 2020-2021 pet food recalls to the corn used in those foods.

What depends on the amount and the recipe

How much of the food's protein it supplies, and whether other proteins or added amino acids make up for its low lysine (and, for cats, its low arginine). The quality of the corn also matters, because FDA notes that aflatoxin levels in corn vary with growing-season weather and storage conditions. Species matters too: the one cat study reviewed found chicken meal as good or better.

Not the same as

• Corn protein feed (corn gluten feed) — A different wet-milling co-product, made mainly of corn bran and corn solubles. AAFCO renamed it at the same time, which makes the two names easy to confuse.
• Wheat gluten — The protein from wheat. AAFCO's ingredient committee notes that corn protein is different from the gluten protein in wheat.
• Ground corn — The whole corn grain, ground. Corn protein meal is only the protein fraction separated out in wet milling.
• Corn germ meal — Made from corn germ after its oil has been extracted, not from the protein fraction.

Sources

1. 2022 AAFCO Annual Meeting Committee Reports: Ingredient Definitions Committee minutes, 22 March 2022 (proposal to publish as Corn Protein Meal) — Association of American Feed Control Officials (AAFCO), 2022. Proposed renaming of corn gluten meal to corn protein meal (and corn gluten feed to corn protein feed). "Gluten" historically meant plant protein generally, and corn protein differs from wheat gluten.
2. 2024 AAFCO Annual Meeting Committee Minutes: Association Business Meeting and Ingredient Definitions Committee, 23 January 2024; Ingredient Definitions Committee virtual spring meeting, 18 April 2024 — Association of American Feed Control Officials (AAFCO), 2024. January 2024 member vote making "Corn Gluten Meal (Corn Protein Meal)" and "Corn Gluten Feed (Corn Protein Feed)" official, with the gluten names to be removed in 2025. Industry concern about label-change costs. April 2024: the attempt to revive the delay motion failed, and enforcement discretion was referred to the Enforcement Issues Committee. Paraphrased description of the wet-milling product.
3. Commission Regulation (EU) 2022/1104 amending Regulation (EU) No 68/2013 on the Catalogue of feed materials (Part C, entries 1.2.8 Maize protein [Maize gluten], 1.2.9 Maize protein feed, 1.2.12 Maize germ meal) — European Union, Official Journal L 177 (Publications Office), 2022. EU name "maize protein" with synonym "maize gluten", described as mainly protein (prolamins) from maize starch manufacture. Maize protein feed is bran plus solubles. 'Maize' may be called 'corn'.
4. Reilly LM et al. Use of the precision-fed cecectomized rooster assay to determine standardized amino acid digestibility, true metabolizable energy content, and digestible indispensable amino acid scores of plant-based protein by-products used in canine and feline diets. Translational Animal Science 5(2):txab025 — Translational Animal Science (open access, via PubMed Central), 2021. Composition and amino acid profile of corn gluten meal, high digestibility except lysine, and lysine first-limiting for dogs and cats (arginine and tryptophan also below 100% for cats). Complementary proteins are needed. The rooster model is not established for cats. Industry support declared.
5. Funaba M et al. Evaluation of meat meal, chicken meal, and corn gluten meal as dietary sources of protein in dry cat food. Canadian Journal of Veterinary Research 69(4):299-304 — Canadian Journal of Veterinary Research (via PubMed Central), 2005. Cat feeding study: digestibility, nitrogen absorption, urine pH and struvite results, and the authors' preference for chicken meal and note on arginine.
6. FDA Report of FY 21 Special Sampling Assignment for Aflatoxins: Kibbled Dog & Cat Food — U.S. Food and Drug Administration, Center for Veterinary Medicine, 2022. 20 ppb aflatoxin action level for dog and cat foods. The survey covered foods with corn by-products including corn gluten (199 kibbled, 1 wet), and none exceeded 20 ppb. The 2020-2021 recalls were traced to corn, and levels vary with weather and storage.

Checked against these sources on 2026-10-15. Definitions are in our own words. This is a reading aid, not veterinary advice: a vet who knows your animal comes first.