Evaluation of hematological, biochemical responses, antioxidant profile and intestinal histology of common carp (Cyprinus carpio) supplemented with mannan oligosaccharides and nucleotides

• Grant number: 23/13022-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2024
• End date: March 31, 2025
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Production
• Principal Investigator: Felipe Pinheiro de Souza
• Grantee: Isabela Bispo Cartone
• Host Institution: Centro Universitário Faculdades Integradas de Ourinhos. Fundação Educacional Miguel Mofarrej. Ourinhos , SP, Brazil

Abstract

Global aquaculture is the animal production sector that has shown the highest growth rate in recent decades. In this context, the intensification of aquaculture production has raised concerns about the use of antibiotics and bacterial resistance, opening the door for alternative products such as prebiotics and dietary nucleotides. The present study aims to evaluate the effects of supplying feed containing a combination of mannan oligosaccharides (MOS) (Hypergen) and nucleotides (Biotide Extra) on the hematological and biochemical parameters, antioxidant profile, and intestinal histology of common carp (Cyprinus carpio). The physical-chemical variables of the water will be measured daily (dissolved oxygen - mg/l; temperature - TºC; pH and ammonia). A completely randomized design will be carried out, with two treatments as follows: Control - fish receiving commercial feed without the inclusion of additives; Supplemented - fish receiving commercial feed plus Hypergen (2.0 g kg-1) + Biotide Extra (2.0 g kg-1), with each treatment consisting of seven replications, each with five fish. After the 42-day experimental period, the fish will be anesthetized (100 mg/L of benzocaine) to measure growth parameters (final weight, weight gain, condition factor, total and standard length). Blood will be collected for hematological tests (erythrocyte count, hematocrit, hemoglobin, and hematimetric indices) and determination of plasma protein concentration. Biochemical parameters (albumin, globulin, cholesterol, triglycerides) and oxidative profile will also be determined, using peroxidase (CAT ABTS+HRP), cupric reduction (CAT-CUPRAC), ferric reduction (CAT-FRAP), and uric acid methods. The fish, still under the influence of the anesthetic, will be euthanized by spinal section, and the proximal and distal intestine will be collected and stored in 10% formaldehyde and later in 70% alcohol. They will then be processed for the morphometric evaluation of the villi and goblet cell count. The data will be subjected to analysis of variance (ANOVA) with a significance level of 5%. Variables that do not exhibit normality of residuals or homogeneity of variances will be subjected to the Wilcoxon-Mann-Whitney test (U test), with a significance level of 5%.