Project description:Frass is the by-product of the larval meal industry and includes larval waste, exoskeleton sheds, and residual feed ingredients. Experimental frass was derived from the larvae of black solder flies (Hermetia illucens) fed distillers dried grains. A 10-week study was conducted to evaluate the effect of dietary levels of frass on the global gene expression of channel catfish, Ictalurus punctatus. Three diets containing 0, 50, and 300 g frass per kg diet were fed to channel catfish (5.24 ± 0.04 g) in quadruplicate aquaria to apparent satiation twice daily. Intestine (n=12 in pools of 3) and liver (n=12 in pools of 3) tissues were taken from fish at the end of the trial and processed for high-throughput Illumina RNA sequencing (RNAseq). Pairwise comparisons identified both up- and down-regulated genes in frass diets compared to no frass controls.