Effects of Dietary Periplaneta americana Residue Supplementation on Porcine Ovaries and Screening Analysis of Functional Small Peptides.

BACKGROUND: Periplaneta americana residue (PAR) has potential as a sustainable insect-derived feed ingredient. This study evaluated the effects of 3% dietary PAR on growth performance and ovarian function in finishing pigs and screened potential bioactive peptides. METHODS: Thirty finishing pigs were assigned to a control diet or a diet containing 3% PAR. Growth traits, serum oxidative and inflammatory indicators, and ovarian histomorphology were assessed in vivo. Multi-omics profiling was integrated with quantitative real-time PCR, Western blotting, and immunofluorescence assays. The properties of selected peptides and their potential interactions with candidate proteins were assessed separately using in silico prediction, molecular docking, and molecular dynamics simulations. RESULTS: PAR supplementation increased average daily gain and the ovary-to-body weight ratio and decreased serum malondialdehyde levels and follicular atresia, without significantly affecting feed intake, feed conversion ratio, or inflammatory cytokines. Multi-omics profiling associated PAR supplementation with changes in ovarian metabolism, antioxidant defense, immune regulation, and phosphorylation-related signaling. MGST2 and PPM1K were identified as candidate proteins, and their expression patterns were supported experimentally. Serum peptidomics identified GVSEIQQ as having higher abundance in the PAR group than in the control group, whereas GVEEHETL and PGIPT were detected only in the PAR group. In silico analyses predicted that these peptides were non-toxic, non-allergenic, and potentially antioxidant; these predictions require experimental validation. Molecular docking and molecular dynamics simulations suggested potential interactions of GVSEIQQ with MGST2 and GVEEHETL with PPM1K. However, these computational findings do not establish direct peptide-protein binding or functional effects in vivo. CONCLUSIONS: PAR shows potential as an alternative feed ingredient that may partially replace soybean meal while supporting growth and ovarian condition in finishing pigs. Further biochemical and in vivo studies are required to confirm the biological functions and mechanisms of the identified peptides.