Effects of Choline Supplementation in Diets on Juvenile Pacu (Piaractus mesopotamicus): Productive Performance, Proximate Composition and Serum Lipid Level.

INTRODUCTION: Pacu (Piaractus mesopotamicus) is a Brazilian fish species of high commercial value and has emerged as one of the main species with potential for intensive farming. This study aimed to investigate the impact of choline supplementation on productive performance, visceral fat, hepatosomatic indices, proximate composition, serum biochemical profile, and liver coloration in juvenile pacu (Piaractus mesopotamicus). METHOD: The 60-day experiment was conducted in the experimental hatchery of the Study Group of Aquaculture Management - GEMAq of the State University of West Paraná, Brazil. The completely randomized design consisted of five treatments with four replicates each. A total of 200 fish, with an average initial weight and length of 4.25 g and 5.97 cm, were distributed among 20 experimental hapas, resulting in a stocking density of 10 fish per experimental unit. Fish fed a choline-deficient diet exhibited the lowest values for final weight, weight gain, visceral fat, and hepatosomatic index. Conversely, in terms of proximate composition, fish fed choline-deficient diets had the highest moisture content but the lowest crude fat content. Triglyceride levels in juvenile pacu were significantly higher in groups fed diets containing choline (400 to 1200 mg kg-1 ). We also observed significant differences in the cyan color of the liver (P < 0.05). Notably, we observed significant differences in the cyan coloration of the liver (P < 0.05). Other parameters did not exhibit significant changes in response to varying choline levels in the diets. RESULT: Our study demonstrated that choline supplementation in P. mesopotamicus juveniles at an optimal concentration of 400 mg kg-1 significantly impacted growth, metabolism, productive performance, proximate composition, biochemical parameters, and liver color. CONCLUSION: These findings offer crucial guidance for aquaculture professionals, enabling them to enhance growth and health in P. mesopotamicus farming. Further research on choline's influence on lipid metabolism holds potential for more precise dietary recommendations, ultimately improving the efficiency and sustainability of aquaculture practices for this species.

Expression of the PEPT1, CAT, SOD2 and GPX1 genes in the zebrafish intestine supplemented with methionine dipeptide under predation risk.

This study evaluated the effect of methionine supplementation, predation risk and their interaction on gut histology, whole-body cortisol levels, and intestinal gene expression in zebrafish. A total of 360 one-year-old animals were maintained under two environmental conditions and fed diets containing different methionine sources. Fish were fed either a control diet (CTL, without methionine supplementation), a diet supplemented with dl-methionine (DLM), or a diet supplemented with methionine dipeptide (MM) in the absence (AP) of a predator or in the presence of the predator (PP) for 48 h or 20 days. Predator-induced stress for 20 days resulted in lower body weight. Zebrafish fed methionine-supplemented diets had higher weight gain than control fish. We found no effect of predation stress or methionine supplementation on cortisol level. Predation risk and methionine supplementation showed no interaction effect on dipeptide transporter gene expression. After 48 h of predation pressure, zebrafish had higher mRNA expression of SOD2, CAT and GPX1 in the gut. After 20 days of exposure to the predator, zebrafish fed methionine-supplemented diets had lower expression of GPX1, SOD2 and CAT than those diet CTL. Methionine dipeptide and free methionine supplementation improved growth, intestinal health and survivability of zebrafish both conditions.

Elaboração de massa fresca de macarrão enriquecida com pescado defumado / Production of fresh paste pasta enriched with smoked fish

O objetivo deste trabalho foi de produzir massa fresca de macarrão com a incorporação de peixe defumado e avaliar as características microbiológicas, físico-químicas e sensoriais. O peixe utilizado para este experimento foi o pacu (Piaractus mesopotamicus), cultivados em tanques rede no Reservatório da Itaipu Binacional no Município de Santa Helena - PR. Foram realizadas análises quanto aos teores de lipídios, umidade, proteínas, minerais totais, carboidratos e valor calórico, além da qualidade microbiológica do produto in natura e da massa de macarrão. A massa de macarrão foi submetida também à análise sensorial com avaliação dos atributos de aparência, cor, odor, sabor e textura. A massa de macarrão apresentou valores de 15,21% de proteínas; as análises físico-químicas indicaram alto teor protéico. Quanto à análise microbiológica do produto, os resultados obtidos apresentaram-se em conformidade com os valores exigidos pela legislação e, portanto, adequado para o consumo humano. A avaliação sensorial da massa de macarrão indicou alta aceitabilidade com 97% de aprovação. O acréscimo de carne de pescado na formulação da massa de macarrão apresentou vantagens qualitativas e quantitativas com relação à sua composição química, além de alta aceitabilidade do produto desenvolvido, o que mostra a viabilidade de sua produção.

The purpose of this study is to prepare fresh paste pasta with the addition of smoked fish, and to assess the microbiological and physical-chemical characteristics, and the sensory aspects. Pacu fish (Piaractusmesopotamicus) bred in captivity in the Binational Itaipu Reservoir located in the City of St. Helena – PR was analyzed on the contents of lipids, protein, total minerals, carbohydrates, moisture and caloric value. TheMicrobiological quality of the fresh product and the prepared pasta was assessed. The sensory aspects of thepasta were used to evaluate the appearance, color, odor, taste and texture characteristics. The pasta paste had 15.21% protein. The physical-chemical analysis on pasta showed high protein contents; and the microbiological results complied with the values established by the legislation in effect, being suitable for human consumption. The acceptability of sensory features on the prepared pasta had 97% of approval. The addition of fish meat in the pasta paste formulation furnished qualitative and quantitative advantages regarding the chemical composition besides the high acceptance, indicating the feasibility of its production.