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ABSTRACT Haematological and plasma parameters are used in veterinary medicine as a diagnostic tool, allowing for the early detection of potential health and welfare issues. For the implementation of monitoring strategies, reference intervals (RIs) are needed to know when deviations in those parameters become clinically relevant. Here, haematological and plasma biochemical RIs of Norwegian Atlantic salmon (Salmo salar Linnaeus) are presented for 29 biomarkers. Two subgroups were defined from the reference population based on water type, referred to as pre‐adult (freshwater, 166.8 ± 118.4 g, N = 979) and adult (seawater, 2655 ± 2883 g, N = 4941), collected at 93 fish farms along the Norwegian coast. While the influence of various pre‐analytical variables on RIs is well documented, aquaculture practitioners cannot always control those variables in the field. Here, RIs were calculated from blood samples collected based on local pre‐analytical practices and then further processed under standardised conditions (analytical phase). RIs are therefore considered highly relevant for the application in the field. Finally, when taking blood samples in the field, it is advised to centrifuge whole blood as soon as possible, while plasma parameters investigated were stable for 168 h at 4°C or 72 h at room temperature. [ABSTRACT FROM AUTHOR]

This study evaluated the optimal dietary copper (Cu) levels and their effects on growth performance, body composition, and antioxidant capacity in juvenile largemouth bass (Micropterus salmoides). A total of 360 fish (initial average weight (1.67 ± 0.01 g) and initial average length (2.5 ± 0.2 cm)) were randomly assigned to 18 tanks, each containing 20 fish and six dietary Cu concentrations: 2.13 (control), 3.00, 3.66, 4.58, 4.64, and 5.72 mg/kg. The results indicated that fish receiving 3.00 mg/kg of Cu exhibited the best final body weight (FBW), weight gain rate (WGR), and specific growth rate (SGR), with a significantly reduced feed conversion ratio (FCR). While body composition (moisture, protein, lipid, and ash) remained consistent across groups, plasma total protein (TP) levels increased with Cu supplementation. Elevated triglycerides (TG) and albumin (ALB) were noted at 4.64 and 5.72 mg/kg, respectively, while glucose (GLU) levels decreased with an increase in dietary Cu. Antioxidant capacity, assessed via hepatic glutathione (GSH) and the activities of catalase (CAT), and showed significant improvements at 3.00 and 3.66 mg/kg Cu, while superoxide dismutase (SOD) showed the highest activity at a dietary Cu level of 5.72 mg/kg. Additionally, the expressions of tgf-β and tnf-α genes were significantly upregulated at a dietary Cu level of 5.72 mg/kg, while il-8 and il-10 genes were upregulated at dietary 3.66 mg/kg. The expression of nrf2 was significantly upregulated in response to a dietary Cu level of 3.66 mg/kg compared to the control group, and the expression of the keap1 gene was significantly upregulated in the fish fed with 5.72 mg/kg of dietary Cu. The results indicated that appropriate dietary supplementation could promote the growth performance and improve the antioxidant status the immunity of largemouth bass, and the optimal Cu requirement for FCR and SGR were approximately 3.10 mg/kg and 3.00 mg/kg, respectively. [ABSTRACT FROM AUTHOR]

【Objective】The experiment was carried out to study the effects of potassium magnesium sulfate (PMS) on sow performance, plasma biochemical indicators, antioxidant capacity and immune function in late pregnancy.【Method】By using simple factor design of the experiment, sixty sows (Landrace×Yorkshire) with 3-4 parity, good health and similar expected delivery in the third trimester of pregnancy (85th day of pregnancy) were randomly divided into 4 groups (15 replicates in each group and 1 sow in each replicate). The experimental groups during gestation were supplemented with PMS 0 (CK), 5, 10 and 15 g/d for each sow, respectively. After delivery, all sows during lactation were fed the same commercial lactation feed. The experiment ended on the 18th day of lactation.【Result】(1) Supplemental PMS had no significant effects on litter size, healthy litter size, back fat thickness, labor, body weight, feed intake in sows during lactation, and newborn weight of piglets, number of weaned piglets and number of deaths of lactating piglets. Compared with the control group, the fecal score of sows during late pregnancy after PMS supplementation showed a linear increase (Plinear < 0.05) and 10 g/d group had significant effects (PANOVA < 0.05); After supplementation with PMS, it showed a linear increase (Plinear < 0.05) in newborn litter weight, litter weight of weaned piglets, average litter gain of lactating piglets and daily gain of lactating piglets (PANOVA < 0.05). Compared with the control group, the newborn litter weight, litter weight of weaned piglets, average litter gain of lactating piglets and daily gain of lactating piglets in the 10 g/d group were increased by 16.27%, 24.42%, 35.14% and 31.64%. Except for newborn litter weight, all other indicators showed quadratic effect (PQuadratic < 0.05) and significant differences were found between groups (PANOVA < 0.05); (2) It showed a linear increase in the contents of triglyceride (TG), cholesterol (CHO), low-density lipoprotein (LDL) and insulin (INS) in plasma of sows supplemented with PMS (Plinear < 0.05). The contents of TG, CHO, LDL and INS in the 10 g/d group increased by 50.00%, 28.35%, 25.00% and 31.98% compared with the control group; TG and LDL had a quadratic effect (PQuadratic < 0.05). (3) Linear changes were found in contents of immunoglobulin G (IgG), immunoglobulin A (IgA), immunoglobulin M (IgM) and glutathione peroxidase (GSH-Px) (Plinear < 0.05) in the plasma of sows after supplementation with PMS, and they were increased by 17.10%, 20.34%, 8.00% and 15.04% in the 10 g/d group, compared with the control group. (4) It showed a linear increase (PANOVA < 0.05) in fat content of colostrum of sow with PMS supplementation (Plinear < 0.05), with significant increase. Non-fat milk solids, lactose and protein were linearly increased (Plinear < 0.05) and had an increasing trend (0.05 < PANOVA < 0.1). The fat content of colostrum supplemented with 10 g/d were increased by 51.42% compared with the control group.【Conclusion】PMS supplementation in late preganancy can significantly improve the fecal scores of sows, relieve sow constipation, and improve sow performance and body health, with 10 g/d supplementation as the optimal dose.

【Objective】The experiment was carried out to study the effects of potassium magnesium sulfate (PMS) on sow performance, plasma biochemical indicators, antioxidant capacity and immune function in late pregnancy. 【Method】By using simple factor design of the experiment, sixty sows (Landrace×Yorkshire) with 3-4 parity, good health and similar expected delivery in the third trimester of pregnancy (85th day of pregnancy) were randomly divided into 4 groups (15 replicates in each group and 1 sow in each replicate). The experimental groups during gestation were supplemented with PMS 0 (CK), 5, 10 and 15 g/d for each sow, respectively. After delivery, all sows during lactation were fed the same commercial lactation feed. The experiment ended on the 18th day of lactation.【Result】(1) Supplemental PMS had no significant effects on litter size, healthy litter size, back fat thickness, labor, body weight, feed intake in sows during lactation, and newborn weight of piglets, number of weaned piglets and number of deaths of lactating piglets. Compared with the control group, the fecal score of sows during late pregnancy after PMS supplementation showed a linear increase (Plinear＜ 0.05) and 10 g/d group had significant effects (PANOVA＜ 0.05); After supplementation with PMS, it showed a linear increase (Plinear＜ 0.05) in newborn litter weight, litter weight of weaned piglets, average litter gain of lactating piglets and daily gain of lactating piglets (PANOVA ＜ 0.05). Compared with the control group, the newborn litter weight, litter weight of weaned piglets, average litter gain of lactating piglets and daily gain of lactating piglets in the 10 g/d group were increased by 16.27%, 24.42%, 35.14% and 31.64%. Except for newborn litter weight, all other indicators showed quadratic effect (PQuadratic ＜ 0.05) and significant differences were found between groups (PANOVA ＜ 0.05) ; (2) It showed a linear increase in the contents of triglyceride (TG), cholesterol (CHO), low-density lipoprotein (LDL) and insulin (INS) in plasma of sows supplemented with PMS (Plinear＜ 0.05). The contents of TG, CHO, LDL and INS in the 10 g/d group increased by 50.00%, 28.35%, 25.00% and 31.98% compared with the control group; TG and LDL had a quadratic effect (PQuadratic ＜ 0.05). (3) Linear changes were found in contents of immunoglobulin G (IgG), immunoglobulin A (IgA), immunoglobulin M (IgM) and glutathione peroxidase (GSH-Px) (Plinear＜ 0.05) in the plasma of sows after supplementation with PMS, and they were increased by 17.10%, 20.34%, 8.00% and 15.04% in the 10 g/d group, compared with the control group. (4) It showed a linear increase (PANOVA ＜ 0.05) in fat content of colostrum of sow with PMS supplementation (Plinear＜ 0.05), with significant increase. Non-fat milk solids, lactose and protein were linearly increased (Plinear＜ 0.05) and had an increasing trend (0.05 ＜ PANOVA ＜ 0.1). The fat content of colostrum supplemented with 10 g/d were increased by 51.42% compared with the control group. 【Conclusion】 PMS supplementation in late preganancy can significantly improve the fecal scores of sows, relieve sow constipation, and improve sow performance and body health, with 10 g/d supplementation as the optimal dose. [ABSTRACT FROM AUTHOR]

Oxolinic acid (OA), a broad-spectrum quinolone antibiotic that plays a crucial role in human medicine, is often used in aquaculture as a second-line treatment at 12 mg/kg biomass/day continuously for seven days. The objective of this study was to assess its effectiveness against Aeromonas hydrophila infection in Nile tilapia Oreochromis niloticus in terms of progression and healing of wounds, clinical biochemistry and histopathological changes upon challenge and treatment. To evaluate the efficacy, the juveniles were intramuscularly challenged with A. hydrophila at a sublethal dose of 1.93×106 cells/fish, followed by the administration of OA-supplemented feed at 2% body weight daily for seven days. OA treatment yielded better consequences in terms of increased feed intake and biomass and decreased plasma biochemical parameters, histopathological changes and improved recovery from A. hydrophila infection compared to the untreated group. Wounds of the OA-treated group healed at a faster rate, with complete healing within 12 days post-injection, while the wounds of the untreated group took longer to heal. Though the efficacy of OA against A. hydrophila infection in tilapia was established in this study, it is important to exercise caution regarding its application in aquaculture due to its classification as a critically important medicine for humans. [ABSTRACT FROM AUTHOR]

Complete blood counts (n=566) and serum biochemistry (n=426) were assessed in seven coastal seabirds species that underwent rehabilitation along the southeastern and southern coast of Brazil from Saquarema, Rio de Janeiro State (22°56′16.44″S, 42°18′24.16″W) to Laguna, Santa Catarina State (28°29′43″S, 48°45′39.2″W), from August 2016 to August 2020. Blood samples were collected from four species of Charadriiformes, including Kelp Gull (Larus dominicanus, n=136), South American Tern (Sterna hirundinacea, n=25), Cabot's Tern (Thalasseus acuflavidus, n=17), and Common Tern (Sterna hirundo, n=14) as well as three species of Suliformes, the Brown Booby (Sula leucogaster, n=212), Magnificent Frigatebird (Fregata magnificens, n=104), and Neotropic Cormorant (Nannopterum brasilianum, n=58). The individuals were sampled as part of the protocol required before their release into the wild when considered healthy. This work aimed to establish the normal hematologic and biochemical reference values of those seabird species and, when possible, to analyze variations among age class and sex and to compare those with the available data in the literature. In addition, we provide the first baseline data for the South American Tern, Cabot's Tern, and Neotropic Cormorant. Baseline hematologic data are crucial for assessing health status of individuals and to support management and conservation actions, including release of seabirds into the wild. [ABSTRACT FROM AUTHOR]

This study evaluated the optimal dietary copper (Cu) levels and their effects on growth performance, body composition, and antioxidant capacity in juvenile largemouth bass (Micropterus salmoides). A total of 360 fish (initial average weight (1.67 ± 0.01 g) and initial average length (2.5 ± 0.2 cm)) were randomly assigned to 18 tanks, each containing 20 fish and six dietary Cu concentrations: 2.13 (control), 3.00, 3.66, 4.58, 4.64, and 5.72 mg/kg. The results indicated that fish receiving 3.00 mg/kg of Cu exhibited the best final body weight (FBW), weight gain rate (WGR), and specific growth rate (SGR), with a significantly reduced feed conversion ratio (FCR). While body composition (moisture, protein, lipid, and ash) remained consistent across groups, plasma total protein (TP) levels increased with Cu supplementation. Elevated triglycerides (TG) and albumin (ALB) were noted at 4.64 and 5.72 mg/kg, respectively, while glucose (GLU) levels decreased with an increase in dietary Cu. Antioxidant capacity, assessed via hepatic glutathione (GSH) and the activities of catalase (CAT), and showed significant improvements at 3.00 and 3.66 mg/kg Cu, while superoxide dismutase (SOD) showed the highest activity at a dietary Cu level of 5.72 mg/kg. Additionally, the expressions of tgf-β and tnf-α genes were significantly upregulated at a dietary Cu level of 5.72 mg/kg, while il-8 and il-10 genes were upregulated at dietary 3.66 mg/kg. The expression of nrf2 was significantly upregulated in response to a dietary Cu level of 3.66 mg/kg compared to the control group, and the expression of the keap1 gene was significantly upregulated in the fish fed with 5.72 mg/kg of dietary Cu. The results indicated that appropriate dietary supplementation could promote the growth performance and improve the antioxidant status the immunity of largemouth bass, and the optimal Cu requirement for FCR and SGR were approximately 3.10 mg/kg and 3.00 mg/kg, respectively.

Cuchia eel (Monopterus cuchia) is among the most sought-after freshwater fish, owing to its exceptional nutritional profile and high consumer demand. The current research aimed to establish baseline data by comparing the proximate composition, hematological, and plasma biochemical indices of Cuchia eel populations across six different geographical locations in Bangladesh: Bogra, Haluaghat, Jamalpur, Moktagacha, Sylhet, and Tangail. By examining these parameters, we aim to gain valuable insights into the nutritional benefits, physiological responses, and potential adaptations of this species to varying environments. The statistical analysis revealed no significant (P > 0.05) variances in the whole-body proximate composition of the fish captured from distinct areas. However, it was observed that different geographical regions had remarkable impacts on the variations of the majority of the hematological parameters, except for some cases. Additionally, there was a notable (P

Sturgeon farming is a rapidly developing aquaculture sector which requires high-quality feeds. As an ingredient of animal feeds, fishmeal is often replaced with cheaper plant-based protein sources, such as rapeseed cake meal, a by-product of canola oil pressing. The aim of the present study is to evaluate the effects of diets containing various levels of rapeseed cake meal on the juvenile Siberian sturgeon (Acipenser baerii) growth, hematological and biochemical parameters, as well as muscle composition. An 8-week feeding trial was conducted on fish with average body weight of 216.2 ± 45.7 g. Fish were fed diets were 0%, 10%, 20%, and 30% of fish meal and soybean meal were replaced with rapeseed meal (groups A, B, C, and D, respectively). Additionally in E diet (30% rapeseed meal) effects of phytase addition RENOZYME® HiPhos 20000 in concentration 2000 IU was tested. During the experiment, no mortalities were observed in each of the studied groups. Similar values of morphometric and breeding parameters were observed in groups A, B, C, D and E. No hematological effects of rapeseed diets occurred, except for significantly lower erythroblast levels in groups B, C, D, and E compared to A. Group B showed a higher plasma glucose concentration compared to the other groups. ALT activity in groups D and E were lower than in groups A, B, and C. The muscles of individuals from group B showed the highest dry matter and fat content, while the highest protein content occurred in group C. Despite significant differences in the values of some parameters, the obtained results indicate that the replacement of 10–30% of fishmeal with rapeseed meal in the feed for the juvenile Siberian sturgeon did not compromise fish survivability, growth performance, health, or body composition, although phytase addition did not improve the effects of administering rapeseed-containing feed.

Reproduction is a physiologically demanding process for sea turtles. Health indicators, including morphometric indices and blood analytes, provide insight into overall health, physiology and organ function for breeding sea turtles as a way to assess population-level effects. The Archie Carr National Wildlife Refuge (ACNWR) on Florida's central eastern coast is critical nesting habitat for loggerhead sea turtles ( Caretta caretta ), but health variables from this location have not been documented. Objectives of the study were to (1) assess morphometrics and blood analyte data (including haematology, plasma biochemistry, protein electrophoresis, β-hydroxybutyrate, trace nutrients, vitamins and fatty acid profiles) from loggerheads nesting on or near the beaches of the ACNWR, (2) investigate correlations of body condition index (BCI) with blood analytes and (3) analyse temporal trends in morphometric and blood analyte data throughout the nesting season. Morphometric and/or blood analyte data are reported for 57 nesting loggerheads encountered between 2016 and 2019. Plasma copper and iron positively correlated with BCI. Mass tended to decline across nesting season, whereas BCI did not. Many blood analytes significantly increased or decreased across nesting season, reflecting the catabolic state and haemodynamic variations of nesting turtles. Twenty-three of 34 fatty acids declined across nesting season, which demonstrates the physiological demands of nesting turtles for vitellogenesis and reproductive activities, thus suggesting potential utility of fatty acids for the assessment of foraging status and phases of reproduction. The findings herein are relevant for future spatiotemporal and interspecies comparisons, investigating stressor effects and understanding the physiological demands in nesting sea turtles. This information provides comparative data for individual animals in rescue or managed care settings and for assessment of conservation strategies., Competing Interests: The authors have no conflicts of interest to declare., (© The Author(s) 2024. Published by Oxford University Press and the Society for Experimental Biology.)

The effects of dietary Hermetia illucens (HI) larvae meal on growth, plasma biochemistry and gut microbiota was tested in gilthead sea bream. Four isonitrogenous and isolipidic extruded diets (50% protein; 14% lipid) with different levels of HI larva meal (0% CTRL, 5% HI5, 10% HI10, and 15% HI15) in partial substitution to fish meal (FM) were administered to triplicate fish groups over 113 days. Diets were designed to partially replace FM, using FM level for practical application. No significant differences (p > 0.05) were observed in terms of final body weight, specific growth rate (SGR), feed intake (FI), feed conversion rate (FCR) as well as feed efficiency parameters such as protein efficiency ratio (PER), gross protein efficiency (GPE), gross lipid efficiency (GLE). At the end of the trial there were not significant differences on growth, feed intake, feed conversion rate and protein efficiency. Among over 20 plasma parameters analyzed, HI inclusion level reduced iron (Fe), potassium (K), creatinine (CREA), aspartate aminotransferase (AST), alanine amino transferase (ALT), creatine kinase (CK), alkaline phosphatase (ALP), lactate dehydrogenase (LDH). The reduction of AST, ALT and ALP might suggest a potential beneficial role of HI for liver integrity and functionality. Concerning gut microbiome (GM) layout, HI was able to induce a shift in the GM structure at any inclusion level considered compared to the control diet increasing the abundance of Bacillaceae (mainly Bacillus and Oceanobacillus) and Paenibacillaceae (Paenibacillus). Taxa that can be involved in chitin degradation and has been recently recognized as novel probiotics for aquaculture. In conclusion, the results of feed intake, growth, feed utilization and plasma biochemistry indicate that HI larvae meal can be successfully incorporated up to 15% in practical aquafeed diets to partially replace FM without any negative effects on growth and feed efficiency. Beyond being a valid alternative protein source for fish meal replacement in this species, it displays gut health functional properties already at low inclusion level. • Partial replacement of FM with HI larvae meal did not affect growth and feed utilization. • HI was able to induce a shift in the GM structure at any inclusion level. • HI increased the abundance of Bacillus and Paenibacillus. [ABSTRACT FROM AUTHOR]

Cuchia eel ( Monopterus cuchia ) is among the most sought-after freshwater fish, owing to its exceptional nutritional profile and high consumer demand. The current research aimed to establish baseline data by comparing the proximate composition, hematological, and plasma biochemical indices of Cuchia eel populations across six different geographical locations in Bangladesh: Bogra, Haluaghat, Jamalpur, Moktagacha, Sylhet, and Tangail. By examining these parameters, we aim to gain valuable insights into the nutritional benefits, physiological responses, and potential adaptations of this species to varying environments. The statistical analysis revealed no significant ( P  > 0.05) variances in the whole-body proximate composition of the fish captured from distinct areas. However, it was observed that different geographical regions had remarkable impacts on the variations of the majority of the hematological parameters, except for some cases. Additionally, there was a notable ( P  < 0.05) increase or decrease in most of the serum biochemical contents in certain localities as compared to others in this study. Light microscopic examination of Cuchia eel blood smears exhibited lower numbers but larger sizes of RBCs. The findings of this study lead to the conclusion that different localities had significant impacts on the hematology and blood biochemical indices of Cuchia eel, even though the whole-body proximate composition showed no significant variations. This research contributes to a deeper understanding of the physiological aspects of Cuchia eel., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)