Effects of different carbohydrates on growth, hepatic glucose metabolism, and gut microbiome of Florida pompano (Trachinotus carolinus)

Authors: PAREDES, JUAN - Harbor Branch Oceanographic Institute; HABTE-TSION, MICHAEL - Aquaculture Research Institute; RICHE, MARTY - Harbor Branch Oceanographic Institute; MEJRI, SAHAR - Harbor Branch Oceanographic Institute; BRADSHAW, DAVID - Harbor Branch Oceanographic Institute; SUN CHIN, LI - Harbor Branch Oceanographic Institute; PERRICONE, CARLIE - Harbor Branch Oceanographic Institute; WILLS, PAUL - Harbor Branch Oceanographic Institute

Submitted to: Aquaculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/28/2025
Publication Date: 2/1/2025
Citation: Paredes, J.F., Habte-Tsion, M., Riche, M., Mejri, S., Bradshaw, D., Sun Chin, L., Perricone, C., Wills, P.S. 2025. Effects of different carbohydrates on growth, hepatic glucose metabolism, and gut microbiome of Florida pompano (Trachinotus carolinus). Aquaculture. 600:742237. https://doi.org/10.1016/j.aquaculture.2025.742237.
DOI: https://doi.org/10.1016/j.aquaculture.2025.742237

Interpretive Summary: Aquafeed expenses constitute up to 60% of the total operational costs for intensive aquaculture production. Thus, lowering prices without altering feed nutritional balance is a priority for economic sustainability of aquaculture and a target research area. Carbohydrates are the cheapest dietary energy source. Its adequate dietary inclusion will reduce lipid and protein catabolism for energy; ultimately, reducing feed cost and ammonia release to the environment. Fish utilization of carbohydrates is specie-specific and depends on carbohydrate source and inclusion levels. Herbivorous and omnivorous freshwater fish will utilize higher carbohydrate levels compared to carnivorous marine fish. Florida pompano reports some nutritional studies, but little is known about carbohydrate metabolism. The objective of this research was to determine the effects of different carbohydrate sources on Florida pompano growth. To this end, five isonitrogenous, isolipidic and isocaloric diets were formulated using different carbohydrate sources. At the end of the 10-week growth trial, fish were assessed for growth performance, feed utilization, body composition, hepatic enzyme activity, gene expression and gut microbiome variations. The results of this study determined that whole wheat grain flour promotes optimal growth performance among the studied carbohydrate sources. These findings are relevant for USA aquaculture allowing farmers to use diets tailored for their specific fish culturing needs, thus reducing production costs.

Technical Abstract: A 10-week feeding trial was conducted to determine an appropriate carbohydrate source by evaluating growth performance, feed utilization, hepatic enzymes activity, whole-body fatty/amino acids composition, liver transcriptomics and gut microbiome of Florida pompano (Trachinotus carolinus). Five isonitrogenous (46.67% crude protein), iso-lipidic (15.15% crude lipid) and isocaloric (385Kcal/100g digestible energy) diets were formulated containing 14% of different source of carbohydrates: whole wheat grain flour (WG), wheat starch (WS), whole corn grain flour (CG), corn starch (CS) and dextrinized corn starch (DCS). The results indicated that Florida pompano showed high survival with no significant difference among treatments; and significantly higher percentage weight gain (PWG), specific growth rate (SGR), and feed efficiency (FE) were observed in fish fed WG diet compared to those fed CS and DCS diets. Protein efficiency ratio (PER) was significantly higher in fish fed WS diet in contrast to those fed CS and DCS diets. Fish fed WG, CG and CS diets presented significantly lower crude fat content, while higher ash content only appeared in fish fed WG diet compared to those fed DCS diet. The lowest taurine content was found in fish fed DCS diet. The lowest blood glucose, plasma cholesterol, and hepatic glucose 6-phosphate were measured in fish fed WG diet, while its hepatic glycogen content was higher than those fed WS diet. Liver transcriptomic analysis revealed differentially expressed genes related to glycolysis, gluconeogenesis, and lipogenesis. The microbial community presented high diversity and richness among treatments. Overall, results indicated that whole wheat grain flour is the more appropriate dietary carbohydrate source based on growth performance, physio-biochemical, and molecular approaches. These data are critical when formulating a complete commercial feed for sustainable and profitable culturing of Florida pompano.