Dietary American Cockroach (Periplaneta americana) Residue in Juvenile Black Carp (Mylopharyngodon piceus): Effects on Growth, Antioxidant Status, Metabolism, and Whole-Body Amino Acid Profile
Simple Summary Fishmeal is an important but increasingly limited ingredient in aquaculture feeds, so alternative and sustainable feed resources are needed. American cockroach residue is a by-product generated after the extraction of useful compounds from American cockroaches, and it still contains nutrients and functional substances. This study evaluated whether this residue could be used in diets for juvenile black carp. The results showed that 5% American cockroach residue maintained growth and feed utilization at levels comparable to the control diet, while also improving selected liver antioxidant responses. However, higher inclusion levels were associated with less favorable feed utilization, changes in metabolism, and alterations in whole-body amino acid composition. Because increasing American cockroach residue also changed the overall ingredient composition of the diets, including reductions in fishmeal, fish oil, and soybean oil, these high-inclusion effects should not be attributed to chitin alone. These findings suggest that a moderate level of American cockroach residue may be useful as a sustainable feed ingredient for black carp, but excessive inclusion should be avoided or further optimized through better diet formulation.