Potential for Using Beetles (Coleoptera: Dermestidae) as Model Organisms to Determine Nutrient Bioavailability for Companion Animal Foods: A Pilot Study

Pet owners have become more aware of how their pet's nutrition can influence the pet's life expectancy, wellness, and energy. Evaluating the new ingredients claiming better pet health for nutrient contributions requires significant investment and targeted animal commitment while current research aims to find alternative approaches. Research on pet foods in universities is overseen by the Institutional Animal Care and Use Committee, which has restrictions on the use of vertebrates in testing but places no restrictions on the use of insects. The research reported here studied three species of beetles (Coleoptera: Dermestidae), <i>Trogoderma variabile</i> (Ballion), <i>Trogoderma inclusum</i> (LeConte), and <i>Dermestes maculatus</i> (DeGeer) as potential model organisms to evaluate pet food nutrient bioavailability. The larvae of all three species were fed a balanced pet food diet under various laboratory conditions to determine their protein efficiency ratios (PERs) over a 144 h period. Results suggested that <i>D. maculatus</i> larvae reared at 27 °C, 60-65% R.H. (relative humidity), and a photoperiod of 16:8 L:D were the most efficient at converting ingested protein into weight gain with an average protein efficiency ratio (PER) of 1.439. Further experiments were conducted using only <i>D. maculatus</i> larvae with shorter time windows of 48 h and 24 h. The 24 h feeding time was successful and yielded an average PER of 2.476. These findings suggest that <i>D. maculatus</i> larvae may be a useful model organism for pet food bioavailability studies.