Dietary supplementation of mineral nanoparticles for channel catfish (Ictalurus punctatus)

Authors: SILVA, VITOR - Universidade Federal De Santa Catarina (UFSC); MOURINO, JOSE - Universidade Federal De Santa Catarina (UFSC); MARTINS, MAURICIO - Universidade Federal De Santa Catarina (UFSC); CARVALHO, PEDRO - Texas A&M University; RODRIGUES, EDGAR - Sao Paulo State University (UNESP); GATLIN III, DELBERT - Texas A&M University; GRIFFIN, MATT - Mississippi State University; Older, Caitlin; YAMAMOTO, FERNANDO - Mississippi State University

Submitted to: Fish Physiology and Biochemistry Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/12/2024
Publication Date: 7/27/2024
Citation: Silva, V., Mourino, J.L., Martins, M.L., Carvalho, P., Rodrigues, E.G., Gatlin, D.M., Griffin, M.J., Older, C.E., Yamamoto, F.Y. 2024. Dietary supplementation of mineral nanoparticles for channel catfish (Ictalurus punctatus). Fish Physiology and Biochemistry Journal. https://doi.org/10.1007/s10695-024-01378-7.
DOI: https://doi.org/10.1007/s10695-024-01378-7

Interpretive Summary: Minerals are necessary to include in manufactured fish feeds to meet their nutritional requirements. Catfish feeds commonly include plant-derived ingredients, which contain high levels of antinutrients that can hinder the uptake of minerals, and thus require higher amounts of minerals be added. In recent years, researchers have begun to look into using mineral nanoparticles instead of the inorganic minerals that are usually supplemented in fish feeds, due to the higher surface area of nanoparticles which may improve mineral bioavailability for the fish. Researchers at Texas A&M University, in collaboration with researchers at the National Warmwater Aquaculture Center, the Federal University of Santa Catarina, and São Paulo State University evaluated the supplementation of iron and copper nanoparticles in channel catfish diets and their implications on growth and health. A trial was carried out for nine weeks to evaluate the effects of feeding channel catfish with different combinations of iron nanoparticles and/or copper nanoparticles in comparison to a control diet containing inorganic iron and copper. Production performance, hematological parameters, intestinal microbiota, and survival upon challenge with Edwardsiella ictaluri, a bacterial catfish pathogen, were evaluated. No differences were detected for production performance or survival after bacterial challenge. Hematological parameters were lower in the fish fed the diet containing copper nanoparticles than the control group, likely due to a lack of iron in the diet, which is important for red blood cell production. Fish fed diets containing copper nanoparticles also had different bacterial communities in the intestines, characterized by higher relative abundances of some lactic acid bacteria. These results suggest mineral nanoparticles can be used in place of inorganic mineral sources, without harmful effects on production performance or health. Additionally, results obtained from the diets containing only copper nanoparticles emphasize the importance of iron supplementation, since it is essential for red blood cell production. Further research is needed to consider the changes to the intestinal bacterial microbiota observed with copper nanoparticle supplementation.

Technical Abstract: This study evaluated the supplementation of iron and copper nanoparticles in channel catfish diets and their influences on growth and health. A comparative feeding trial was carried out for 9 weeks to evaluate combinations of iron and copper nanoparticles: only iron nanoparticles (IronNP), only copper nanoparticles (CopperNP), CopperNP + IronNP, and a control diet supplemented with inorganic iron and copper (FeSO4 and CuSO4). After a 9-week feeding trial, growth performance, hematological parameters, whole-body proximate composition, and intestinal microbiota were evaluated, and fish were subjected to a bacterial challenge against Edwardsiella ictaluri to evaluate the contribution of the experimental treatments to fish health status. No statistical differences were detected for catfish fed the various diets in terms of production performance or survival after bacterial challenge. The hematocrit and RBC counts from fish fed the diet containing copper nanoparticles were significantly lower than the control group. A higher relative abundance of gram-positive bacteria was found in the digesta of catfish fed diets containing copper nanoparticles. Furthermore, in the context of hematology, iron nanoparticles did not impact the blood parameters of channel catfish; however, reduced hematocrits were observed in fish fed the copper nanoparticle diet, which lacked supplemental dietary iron, thus reinforcing the importance of dietary iron to catfish hematopoiesis. Nonetheless, additional studies are needed to investigate the effects of dietary copper nanoparticle supplementation in catfish diets to better illuminate its effects on the intestinal microbiota.