Author: marina02

Population structure and genetic identification of Anisakis spp. from juvenile Atlantic bluefin tuna from eastern Adriatic sea

Introduction: Nematodes of the genus Anisakis Dujardin, 1845 are recognised as an emerging public health problem due to their zoonotic potential and ability to cause anisakiasis after consuming raw or undercooked seafood. In the life cycle of Anisakis, fish serve as paratenic hosts, allowing parasite accumulation along the trophic chain. The Atlantic bluefin tuna (ABT) (Thunnus thynnus) is a large pelagic fish with very high economic value. As an apex predator and opportunistic feeder, this species is susceptible to accumulating large numbers of these parasites.
Methodology: Sixty-four juvenile ABTs (mean length ± SD: 21.11 ± 3.11 cm) were caught by purse seine or handline fishing in 2022. The viscera of the fish were removed and analysed under a stereomicroscope for the presence of nematode larvae. Parasite prevalence, mean intensity and mean abundance were calculated using the Quantitative Parasitology web interface. A subsample of nematodes was identified by PCR-RFLP of the ITS locus and sequencing of the cytochrome c oxidase subunit 2 (COII). Genetic diversity indices and genetic population structure were assessed, and a phylogenetic tree was derived by Bayesian inference.
Results: A total of 334 nematodes were recovered, with a prevalence of 50.0% (Sterne’s exact 95% CI 0.374 to 0.626), mean intensity 10.4 (bootstrap 95% CI 8.25 to 12.5) and mean abundance 5.22 (bootstrap 95% CI 3.69 to 7.07). Of 113 genotyped specimens, 106 (93.8%) had the restriction pattern of A. pegreffii and 7 (6.2%) had the recombinant genotype of A. pegreffii × A. simplex. Sequences of COII were obtained for 62 specimens, of which 61 (98.8%) belonged to A. pegreffii and a single sequence (1.2%) to A. simplex. The population exhibited a high haplotype and low nucleotide diversity with no clear genetic structure. This was also confirmed by a very flat phylogenetic tree, in which most of the sequences were located on the main branch, and a single small cluster was separated from the main branch.
Conclusions:  Juvenile ABTs showed a moderate prevalence and intensity of Anisakis spp. infection. Given the species’ trophic position and life history, the intensity of infection is likely to increase with age, highlighting a potential food safety risk for humans. The lack of genetic structure within the population could indicate that spawning and recruitment take place in the Adriatic Sea.

1. HRABAR, JERKO, INSTITUTE OF OCEANOGRAPHY AND FISHERIES, Presenter
2. Žuvić, Luka, Institute of Oceanography and Fisheries, Author
3. Ćurko, Tena, University of Split, Department of Marine Studies, Author
4. Bračić, Katarina, University of Split, Department of Marine studies, Author
5. Trumbić, Željka, University of Split, Department of Marine studies, Author
6. Ivanišević, Klara, Institute of Oceanography and Fisheries, Author
7. Bakarić, Klara, Institute of Oceanography and Fisheries, Author
8. Šegvić Bubić, Tanja, Institute of Oceanography and Fisheries, Author
9. Grubišić, Leon, Institute of Oceanography and Fisheries, Author

You may only eat what you can hold on to, the impact of nematode morphology on pathology

The African sharptooth catfish, Clarias gariepinus (Burchell, 1822) is a preferred aquaculture species in Africa. They are omnivorous and therefore host a large variety of parasites. Their pathology was compared to the morphology of the parasites. Fish were collected from natural water bodies and screened for parasites. Three nematode species were identified, Spinitectus petterae Boomker, 1993, Procamallanus (Procamallanus) laeviconchus(Wedl, 1861), Paracamallanus cyathopharynx (Baylis,1923).attached to the posterior cardiac stomach, intestine and rectum respectively. Host and parasite tissue intended for histology were fixed in 10% neutral buffered formalin, dehydrated in increasing concentrations of ethanol and embedded in resin. Blocks were sectioned with a glass knife on a rotary microtome and sections stained with haematoxylin and eosin. For scanning microscopy, parasites and host tissue were fixed in 70% ethanol, dehydrated in increasing concentrations of ethanol, transferred to increasing concentrations of hexamethyldisilazane and dried in a desiccator, mounted with carbon tape and coated with gold. The stomach features deep folds and S. petterae have robust annular rings with cuticular triangular outgrowths around the head region, a tiny rigid buccal capsule and a muscular oesophagus. Observations of live specimens showed that they manoeuvre in a rotor-wise manner between stomach folds, causing deep pits and sloughed tissue. Leucocyte infiltrations, acute ulcerations, destruction of the lamina propria and the gastric gland layer and granuloma formation was observed. The parasites became deeply inbedded and the cuticular outgrowths act in a harpoon-like manner to maintain its position. Eggs become trapped in the granulomas. Sloughed host tissue is sucked into the oesophagus. In the camallanids the cuticle is smooth, and the buccal capsules are large cup-shaped structures. In P.laeviconchus the buccal capsule is simple and rigid with an anterior and posterior section. Parasites retain their position with as vacuum created when the rim of the buccal capsule is placed on the intestinal epithelium and enlargement of oesophagus. It also sucks epithelial and connective tissue into the buccal capsule. Ingestion follows when sloughing of cells enter the buccal the capsule and eventually the intestine. In Paracamallanus P. cyathopharynx there are two external tridents lateral to the buccal capsule. Internally ridges occur on the dorsal and ventral surface and the capsule can be closed. Parasite attach to secondary folds by closing the buccal capsule and forming an impression on host epithelium. No immunological response was noticed. Morphology of the parasites restrict niche, cause aggregation, reduce competition and supports reproduction.

1. AVENANT-OLDEWAGE, ANNEMARIÈ, UNIVERSITY OF JOHANNESBURG, Presenter

Infection dynamics of infectious hematopoietic necrosis virus in rainbow trout during sexual maturation

Infectious hematopoietic necrosis (IHN) has caused significant losses in rainbow trout aquaculture in Japan. IHNV is detected in brood fish during the spawning season. A scenario in which depression of fish immunity during the maturation process may permit reactivation of latent or persistent virus in fish has been considered. However, our recent epidemiological study suggests that brood fish can be re-infected with IHNV during maturation in an environment where IHNV is always present. In this study, we studied the infection dynamics of IHNV in rainbow trout during maturation at the Nagano Prefectural Fisheries Experiment Station in 2021 and 2022.
The fish groups were affected with IHN at the fry stage and subsequently grew to 2+ years old under the IHNV present environment. After being euthanized with an overdose of 2-phenoxyethanol, the organs (kidney, spleen, pancreas-pyloric caeca, liver, heart, brain, and gonad) and ovarian fluid (spawner) were sampled for virus isolation and titration on EPC cells in the course of the first spawning. Neutralizing and ELISA antibody titres in the serum were measured using isolates from the brood fish and dead fry in 2019.
No virus was isolated from fish with gonad-somatic index (GSI) ranging from 0.1 to 17.5 (12 fish in 2021, 17 fish in 2022), except the ovary of one individual with GSI of 18.9, just before spawning, in 2022. Virus was isolated from the ovarian fluid of spawned fish (7/12 in 2021, 4/12 in 2022), and some virus-positive fish showed infective titre over 10⁵ TCID₅₀/mL in the ovarian fluid and also at 10^2-3 TCID₅₀/g levels in other organs. However, no virus was isolated from the kidney of all fish including the spawners. No or low neutralizing antibody titre was detected in the serum. ELISA antibody titres to fry isolates were higher in pre-matured fish than in spawners, and the titres to brood fish isolates in virus-positive spawners showed a slight increase from those of virus-negative spawners. The results suggest that IHNV re-infects the gonad in brood fish just before spawning, and, in case the virus propagates over 10⁵ TCID₅₀/mL level in the gonad, the virus can spread to other organs. Virus tropism to the ovary in the brood fish may cause selection of viruses present in the environment, resulting in genetic differences from the fry isolates. The re-infection induces a weak antibody response in the spawner, but it is not enough to control the virus in the fish.

1. SANO, MOTOHIKO, Tokyo University of Marine Science and Technology, Presenter
2. SHIMIZU, RYOTA, Tokyo University of Marine Science and Technology, Author
3. NONAKA, AOI, Tokyo University of Marine Science and Technology, Author
4. THIN, CHAW SU, Tokyo University of Marine Science and Technology, Author
5. TSUBOI, GOSUKE, Tokyo University of Marine Science and Technology, Author
6. HIRABE, SUGURU, Tokyo University of Marine Science and Technology, Author
7. SHIROTORI, FUMIAKI, Nagano Prefectural Fisheries Experimental Station, Author
8. TAKEUCHI, KOUTA, Nagano Prefectural Fisheries Experimental Station, Author
9. TAKEHANA, KOUTA, Nagano Prefectural Fisheries Experimental Station, Author
10. FURIHATA, MITSURU, Nagano Prefectural Fisheries Experimental Station, Author
11. NAKAMURA, EISUKE, Fuji Trout Hatchery, Shizuoka Prefectural Research Institute of Fishery and Ocean, Author
12. TAKIKAWA, TOMOHITO, Fuji Trout Hatchery, Shizuoka Prefectural Research Institute of Fishery and Ocean, Author
13. MATSUMOTO, MEGUMI, Tokyo University of Marine Science and Technology, Author
14. KATO, GOSHI, Tokyo University of Marine Science and Technology, Author

Efficacy of a phytobiotic-based additive in controlling natural ectoparasite infestations in farmed grouper, Epinephelus fuscoguttatus

Ectoparasitic infections are a major health challenge in grouper (Epinephelus fuscoguttatus) farming in Asia, particularly during the early stages of culture. Parasites such as Zeylanicobdella, Caligus, Trichodina, and Dactylogyrus infest the gills, skin, and mucus, causing lesions that facilitate secondary bacterial invasion by opportunistic pathogens like Vibrio spp. This co-infection impairs fish health, compromises immunity, and reduces growth and survival.

This study evaluated the efficacy of APEX (Adisseo), a phytobiotic-based additive designed to support skin immunity and resilience under farming conditions. Juvenile groupers (8 ± 0.5 g) were stocked at 75 fish per hapa, in triplicate, and reared in open-water conditions for 90 days. Fish were fed diets supplemented with 0, 3, or 7 g/kg of APEX via top-coated pellets.

The functional additive significantly reduced parasite prevalence (percentage of infected fish) and mean intensity (average number of parasites per infected fish). In both the medium- and high-dose treatments, Zeylanicobdella and Dactylogyrus prevalence remained below 10%, while Caligus and Trichodina prevalence dropped to 11% and 9%, respectively, compared to 71-87% in the control group. Mean intensity was also significantly reduced, indicating not only fewer infected fish but also milder infections. As the ectoparasite burden decreased, Vibrio spp. loads in both kidney and skin tissues dropped by over 80%. These pathogen reductions corresponded with enhanced immune responses. Hematological parameters, including red and white blood cell counts, hemoglobin, lymphocytes, and monocytes, increased by 10-20% in the medium-dose group and 25-40% in the high-dose group, reflecting improved systemic immunocompetence under farm stress conditions.

Consequently, fish showed improved performance, with daily weight gain increasing by up to 14%, FCR improving by 10%, and morphometric indices (length, thickness, and condition factor) significantly enhanced. These findings demonstrate that APEX improves health status and productivity in grouper farming through integrated pathogen control and immune support.

1. CHEN, I-TUNG, Adisseo France SAS, Presenter
2. ISERN-SUBICH, MARIA MERCÈ, Adisseo France SAS, Author
3. NUEZ-ORTÍN, WALDO G., Adisseo France SAS, Author

Methionine dietary supplementation improves antiviral response of rainbow trout (Oncorhynchus mykiss) against viral hemorrhagic septicemia virus (VHSV) – a transcriptomic approach

Several studies have shown that methionine supplementation in fish diets enhances immune function, modulates inflammatory responses, and improves resistance to bacterial infections. These effects are mediated through the regulation of key metabolic pathways such as DNA methylation, aminopropylation, and transsulfuration. However, the immunomodulatory potential of methionine during viral infections remains largely unexplored.

This study aimed to evaluate the effects of dietary methionine supplementation on immune modulation and resistance to viral hemorrhagic septicemia virus (VHSV) in rainbow trout (Oncorhynchus mykiss). Juvenile trout (5.9± 0.9g) were fed for four weeks with one of two experimental diets: a control diet (CTRL) meeting all standard nutritional requirements, including essential amino acids, and a methionine-supplemented diet (MET, 1% of L-methionine in feed).

Following the feeding period, fish were bath-challenged with VHSV at a concentration of 10⁵ TCID50/ml, while control fish were exposed to a virus-free bath. Tissue samples (gills, skin, liver, head kidney, and spleen) were collected at 0 (immediately post-feeding), 24, 72, and 120 hours post-infection for viral load quantification. Based on viral copy numbers, peak infection occurred at 72 hours post-infection, which was supported by the number of differentially expressed genes (DEGs), both upregulated and downregulated in skin and gill tissues. To further investigate the immune response at 72 hours, RNA sequencing (RNA-seq) was conducted on gill and skin tissues. Gene ontology (GO) enrichment analysis of MET-specific DEGs identified significant upregulation of pathogen recognition and signalling pathways (e.g., TLR3, MYD88, TRAF2, NF-κB, STING, IRF3, IRF7), as well as GO terms associated with antiviral responses, apoptosis, and inflammation (e.g., VIG1, caspases, cathepsins, TNF). Notably, viperin—a key antiviral protein encoded by VIG1 and containing a SAM (S-adenosyl-L-methionine) radical domain—was significantly upregulated in the gills of MET-fed fish. This finding underscores the role of methionine in promoting viperin expression and strengthening antiviral defenses, highlighting its critical function in the innate immune response to VHSV in rainbow trout. It further supports the connection between methionine metabolism and antiviral immunity

In summary, this study demonstrates that methionine supplementation can enhance the antiviral immune response in rainbow trout, with viperin emerging as a central effector. These findings suggest that dietary methionine supplementation could serve as a promising prophylactic strategy in aquaculture, contributing to improved fish health and disease resilience.

Work funded by the European Union’s Horizon Europe research and innovation programme (GA No.101079467 project GRINNAQUA). BC and MM were supported by FCT, Portugal (2020.00290.CEECIND and 2022.03304.CEECIND, respectively).

1. Vaz, Mariana, Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Author
2. Themudo, Gonçalo, Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Author
3. Tafalla, Carolina, National Institute for Agricultural and Food Research and Technology (INIA), Spanish Research Council (CSIC), Author
4. Días-Rosalez, Patrícia, National Institute for Agricultural and Food Research and Technology (INIA), Spanish Research Council (CSIC), Author
5. Robledo, Diego, The Roslin Institute and Royal (Dick) School of Veterinary Studies, Author
6. Costas, Benjamín, Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Author
7. Machado, Marina, Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Presenter

Negative effects of a high starch diet in European perch

Introduction

European perch (Perca fluviatilis) is a native fish species, which is highly appreciated for its meat in Switzerland. However, most of the perch consumed in Switzerland originates from wild populations in Eastern Europe. To increase the amount of locally produced aquaculture fish, a large recirculation farm started production of perch in 2007. As a young industry, knowledge about the needs of this fish species is limited. The absence of suitable perch feed was one of the main challenges for the company. This was reflected in excessive fat deposition in the fish organs and body cavity, leading to liver damage and, consequently, increased stress. This resulted in higher disease susceptibility and mortality rates.

Methodology

Under regular production conditions in a fish farm, a batch of perch weighing 22 grams was divided into two groups. One group was fed the previous feed, while the other group received a new formulation. The composition of the new feed contained less starch (7.4% vs. 14.0%) but more protein and fat (54.6% vs. 48.7% and 14.0% vs. 12.0%, respectively).

Four sampling events took place. The first sampling (t0) was conducted before change of feed, afterwards fish were sampled 104 days (t1), 181 days (t2), and 215 days (t3) post feed change. The length and weight of the fish, as well as the weight of the organs (viscera, liver, perivisceral fat tissue, and female gonads), were measured in 20 fish per group and sampling. In parallel, a semi-quantitative histological examination of the liver was conducted on 10 fish per group and sampling. A lesion score was assigned for each liver lesion.

Results and Conclusion

The results showed that reducing the starch content in the feed decreased fat deposition in the liver, and body cavity. Additionally, the semi-quantitative histological examination of the livers revealed a significant decrease in the lesion score. Compared to the former feed, the mortality rate was also lower.

Fish-eating fish species consume only small amounts of starch. This might explain why European perch apparently cannot efficiently utilize starch, leading to unusual fat deposition. This fat deposition, in turn, has a negative impact on fish health.

However, significant variations were observed within the groups. Pre-existing damage due to inappropriate feeding during the rearing process could be an explanation. Nevertheless, it cannot be ruled out that other factors, e.g. bacterial infection with Francisella noatunensis subsp. orientalis, may also play a role.

1. DISERENS, NICOLAS, INSTITUTE FOR FISH AND WILDLIFE HEALTH, Presenter
2. SCHMIDT-POSTHAUS, HEIKE, INSTITUTE FOR FISH AND WILDLIFE HEALTH, Author

DEVELOPMENT OF ANIMAL HEALTH MODELS FOR EMERGING PATHOGENS IN EUROPEAN SEA BASS (Dicentrarchus labrax) IN THE MEDITERRANEAN

Bacterial diseases pose a major challenge in Mediterranean aquaculture, particularly due to the emergence of new pathogens. Among these, Aeromonas species have been frequently linked to disease outbreaks in marine fish. In recent years, Aeromonas veronii has become a significant threat to European sea bass (Dicentrarchus labrax), especially during periods of high water temperature. Climate change has intensified this issue by extending warm periods, leading to more frequent and persistent outbreaks and promoting the emergence of additional pathogens.
Given current restrictions on antibiotics and chemicals in aquaculture, the industry urgently needs effective, sustainable prevention strategies. This requires the development of standardized infection models to assess the efficacy of treatments. In this context, we have focused on developing and testing infection models for A. veronii, with plans to include other emerging pathogens like Lactococcus garvieae.
Two infection models for A. veronii were standardized: intraperitoneal (IP) injection and
bath immersion. Both were tested under various conditions to determine their reproducibility and sensitivity. Preliminary results show that pathogenicity varies with temperature and is influenced by other factors such as fish size, batch, and culture density. Future work will focus on developing a cohabitation model and extending testing to additional pathogens.  The bacterial strain used in the models was isolated from diseased sea bass during a natural  outbreak in a Turkish farm. The strain, identified as A. veronii through MALDI-TOF analysis, was cryopreserved and stored as strain CT0068. Infection tests began with a virulence confirmation trial using IP injection, followed by dose-response trials.
For IP infection, 0.1 ml of bacterial suspension (diluted from a cryopreserved stock at 1×10⁹ CFU/mL) was injected per fish. Bath infection involved immersing fish in seawater
containing the bacteria at various concentrations for one hour. All fish were deeply
anesthetized during handling, and control groups were included in every trial. Each condition was tested in triplicate, with 10 fish per tank. After exposure, fish were transferred to recirculating aquaculture systems (RAS) and monitored. Results demonstrated a clear dose-response effect for both IP and bath methods, confirming the reliability of these models for testing preventive measures against A. veronii. These models offer a valuable tool for developing sustainable disease management strategies in Mediterranean aquaculture.

1. Folgueira, Iria, Centro Tecnológico de Acuicultura de Andalucía (CTAQUA), Presenter
2. Cabello-Gómez, Jose F., Centro Tecnológico de Acuicultura de Andalucía (CTAQUA), Author
3. Páez, Daniel, Centro Tecnológico de Acuicultura de Andalucía (CTAQUA), Author
4. Iglesias, Iria, Centro Tecnológico de Acuicultura de Andalucía (CTAQUA), Author
5. del Mar Agraso, María, Centro Tecnológico de Acuicultura de Andalucía (CTAQUA), Author

An Atypical Course of Cardiomyopathy Syndrome (CMS) in Farmed Atlantic Salmon (Salmo salar) Fed a Clinical Nutrition Diet

Cardiomyopathy syndrome (CMS) poses a significant threat to farmed Atlantic salmon (Salmo salar), leading to high mortality rates during the seawater phase. Given that controlled experimental challenge trials with PMCV do not reproduce the mortality observed in severe field outbreaks of CMS, field trials on natural CMS outbreaks are warranted. This field study explored the impact of a clinical nutrition intervention, specifically a diet enriched with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), on a severe CMS outbreak in a commercial sea farm.

CMS was diagnosed in a single sea cage with high mortality rates. Histopathological analysis, RT-qPCR in situ hybridization for virus detection, and fatty acid composition analysis were used to monitor the impact of disease and the inclusion of EPA and DHA in heart tissue.

Following the implementation of clinical nutrition, a decline in mortality rates, regression of CMS-associated changes, and a significant reduction in piscine myocarditis virus (PMCV) RNA load were observed within the salmon population. Fatty acid composition analysis of heart samples demonstrated increased levels of EPA and DHA, reinforcing the association between dietary factors, viral load dynamics, and overall fish health. Although further validation is needed in future studies, as field trials may not be sufficient to establish causation, our results indicate that optimizing the EPA + DHA levels may prove beneficial in severe CMS outbreaks.

1. RENNEMO, JOHAN, SKRETTING AS, Presenter
2. Berge, Kjetil, Skretting AS, Author
3. Yousaf, Muhammad Naveed, Skretting Aquaculture Innovation, Author
4. Eriksen, Tommy Berger, Skretting Aquaculture Innovation, Author
5. Welde, Eirik, Nordlaks Havbruk As, Author
6. Robertsen, Camilla, Nordlaks Havbruk AS, Author
7. Johansen, Bjarne, Nordlaks Havbruk AS, Author
8. McGurk, Charles, Skretting Aquaculture Innovation, Author
9. Rimstad, Espen, Unit of Virology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Author
10. Koppang, Erling Olaf, Unit of Anatomy, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Author
11. Bjørgen, Håvard, Unit of Anatomy, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Author

Evaluation of dietary black garlic peel as an alternative to antibiotics in rainbow trout (Oncorhynchus mykiss)

Saeyeon Lim and Youngjin Park

Department of Aquatic Life Medical Sciences, Sunmoon University, Asan 31460, Republic of Korea

Introduction: Antibiotics are commonly used in aquaculture, but their misuse has raised concerns about resistance and environmental impact. Plant-derived bioactive compounds offer a safer, eco-friendly alternative with antioxidant and immune-enhancing benefits for fish. Black garlic peel is a by-product rich in polyphenols and flavonoids, exhibiting strong antioxidant activity. However, it is largely discarded and has been rarely studied as an aquafeed ingredient. This study aimed to evaluate the potential use of black garlic peel as a functional feed additive in rainbow trout, with a particular focus on its effects on liver health.

Methodology: Black garlic was prepared via thermal aging, and its peel was incorporated into a commercial trout diet at 0%, 1%, 2%, and 3%. Rainbow trout (13.6±0.7g, 11.5±0.2cm) were distributed into 120 L freshwater tanks (pH 7.4–7.6, DO 9–10 mg/L, 12.8±0.2°C) at 20 fish per group and fed for 8 weeks. Blood was collected for antioxidant analysis, and liver tissue was sampled for gene expression analysis.

Result: Growth performance significantly improved in the 3% group compared to the 0 % group. Blood biochemical analysis (SOD, GPx, GOT, GPT) showed increasing trends with higher inclusion levels, though not statistically significant.

RNA-sequencing revealed that metabolic and hepatic stress-related genes (pgm1, pla2g3, phka2, and mrpl9) were upregulated in the 3% group compared to those of 0% group. These results suggest increased hepatic metabolic activity and cellular stress. Notably, S-allyl cysteine (SAC), a major sulfur-containing compound abundant in black garlic peel, is known for its antioxidant and detoxifying effects at moderate levels. However, at higher concentrations, SAC may induce cytochrome P450 (CYP450) enzyme activity and elevate reactive oxygen species (ROS) production, potentially leading to oxidative stress and liver damage. The observed gene expression changes support the possibility of hepatotoxic effects under excessive dietary inclusion.

Conclusion: Black garlic peel may serve as a functional feed additive that promotes growth in rainbow trout when used at appropriate levels. However, its high-dose application may pose hepatotoxic risks, emphasizing the need for further studies to determine optimal dosage and long-term safety.

Keywords: black garlic peel, hepatotoxic, fish feed, rainbow trout

Funding: Sunmoon University, NRF (National Research Foundation of Korea)

1. Saeyeon, Lim, Sunmoon University, Presenter
2. Youngjin, Park, Sunmoon University, Author

Functional Role of Vitamin E Supplementation in Enhancing Growth performance and Biochemical Resilience in Nile Tilapia (Oreochromis niloticus)

Vitamin E plays an important role in animal diets. It regulates many body functions like growth, antioxidant defenses and digestion. Objective of the study was to determined role of supplementary Vitamin E (VE) affects the growth and Biochemical parameters and digestive enzyme activity in Nile tilapia (Oreochromis niloticus). The fish were divided into four groups with following particular doses of VE. Group (T0) 0 mg/kg of VE, (T1) 200 mg/kg, (T2) 400 mg/kg, and (T3) 600 mg/kg. The experiment conducted for two months. Daily length gain (DLG), daily weight gain (DWG), specific growth rate (SGR), feed conversion ratio (FCR), and condition factor (CF) were measured. one-way ANOVA was sued to analyze differences in the growth performance and enzyme results. A T-test was used to compare the mean values. All the data was analyzed using Statistix 8.1 software. The results indicated that fish in group T3 had the best growth. They had the highest DWG, DLG, SGR, best FCR and Biochemical enzyme activity in the gills, muscles, liver, brain and gut. Group T3 had the highest levels of peroxidase (POx), superoxide dismutase (SOD), catalase (CAT) and protease. T1 showed the lowest enzyme activity. The result suggest that VE helped the fish grow better and improved their antioxidant and digestive enzyme activity.

Keywords: Growth performance, Antioxidant enzymes, Peroxidase (POx), Superoxide dismutase (SOD), Catalase (CAT), Protease activity, Feed conversion ratio (FCR), Biochemical parameters

1. KHURSHEED, ZULFIQAR, CHOLISTAN UNIVERSITY OF VETERINARY AND ANIMAL SCIENCE, Presenter
2. Irshad, Muhammad Hamid, CHOLISTAN UNIVERSITY OF VETERINARY AND ANIMAL SCIENCE, Author
3. Naz, Huma, Cholistan university of veterinary and animal science, Author
4. Manzor, Murtaza, Cholistan university of veterinary and animal science, Presenter
5. Younus, Muhammad, Cholistan university of veterinary and animal science, Author