Mealworms serve as an alternative protein source for pet food. Because the amino acid (AA) content and protein quality of yellow mealworm-based ingredients may vary depending on their husbandry, harvest, and processing procedures, testing of each is required. Our objective was to measure the AA composition, AA digestibility, and protein quality of the following ingredients using the precision-fed cecectomized rooster assay: 1) defatted yellow mealworm (Tenebrio molitor) flour without cuticles (TM); 2) defatted yellow mealworm flour with cuticles (TMc); and 3) whole yellow mealworm pulp (TMp). All ingredients had high digestibilities, with indispensable AA digestibilities being > 90% with the exception of histidine and valine for TMc. Digestible indispensable AA score (DIAAS)-like values were calculated to determine protein quality for adult dogs, adult cats, growing puppies, and growing kittens. DIAAS-like values were highest for TM and considered to be a high-quality protein source for most guidelines and life stages, with DIAAS-like values for TMc and TMp being slightly lower. Although there were slight differences among ingredients, our results demonstrate that yellow mealworm-based ingredients are high-quality protein sources. Dog and cat studies are necessary, but these data suggest that they are suitable sources of protein for pet foods.

Read the full article in the Journal of Animal Science.