Impact of dietary leaf extracts of Black pepper Piper nigrum L on the growth, hematological and immunological parameters of Labeo rohita (Hamilton, 1822) cultured in glass aquaria / Impacto de extratos de folhas da dieta de pimenta-do-reino Piper nigrum L sobre o crescimento, parâmetros hematológicos e imunológicos de Labeo rohita (Hamilton, 1822) cultivado em aquários de vidro

A study was conducted to evaluate the effect of Piper nigrum (black pepper) leaf extract on on the growth performance, proximate composition, hematological parameters, and immune response of Labeo rohita fingerlings with an average weight of 22.14 ± 0.98g. After acclimation for two weeks, fish (n=25) were randomly selected and placed in four glass aquaria (T0, T1, T2 and T3) at constant water temperature (30.0 ± 1.0 °C), pH (7.50 ± 0.5) and total hardness (200 ± 2.0 mgL,-¹) for a period of 12 weeks, with three replicates each. Fish were fed with P. nigrum leaf extract supplemented feed @ 0.0%, 1.0%, 2.0% and 3.0% in T0, T1, T2 and T3, respectively. At the end of experiment, five fish were randomly selected from each aquaria for proximate composition, gut and skin microbial load, hematological parameters. Total proteins, albumins, and globulins were also recorded to evaluate immunological memory. The result revealed that fish in T2 showed better growth performance with an average weight gain of 56.11 ± 0.51 g. Thus, it had been concluded that Piper nigrum, a medicinal plant, can also be used to enhance the growth performance and immune response of Labeo rohita as attractive alternatives against antibiotics and vaccines and has shown no negative side effects on fish health as well as on its environment.

Um estudo foi conduzido para avaliar o efeito do extrato da folha de Piper nigrum (pimenta-do-reino) sobre o desempenho de crescimento, composição centesimal, parâmetros hematológicos e resposta imune de alevinos de Labeo rohita com peso médio de 22,14 ± 0,98g. Após aclimatação por duas semanas, os peixes (n = 25) foram selecionados aleatoriamente e colocados em quatro aquários de vidro (T0, T1, T2 e T3) em temperatura constante da água (30,0 ± 1,0 °C), pH (7,50 ± 0,5) e dureza total (200 ± 2,0 mgL-¹) por um período de 12 semanas, com três repetições cada. Os peixes foram alimentados com ração suplementada com extrato de folha de P. nigrum @ 0,0%, 1,0%, 2,0% e 3,0% em T0, T1, T2 e T3, respectivamente. Ao final do experimento, cinco peixes foram selecionados aleatoriamente de cada aquário para composição centesimal, carga microbiana intestinal e cutânea e parâmetros hematológicos. Proteínas totais, albuminas e globulinas também foram registradas para avaliar a memória imunológica. O resultado revelou que os peixes em T2 apresentaram melhor desempenho de crescimento com ganho de peso médio de 56,11 ± 0,51 g. Assim, concluiu-se que Piper nigrum, uma planta medicinal, também pode ser usado para melhorar o desempenho de crescimento e resposta imunológica de Labeo rohita como alternativas atraentes contra antibióticos e vacinas e não mostrou efeitos colaterais negativos na saúde dos peixes, bem como sobre seu ambiente.

Chromium supplemented carbohydrate diets for Cirrhinus mrigala: effects on body composition, gut enzyme activity and hematological parameters / Dietas com carboidratos suplementados com cromo para Cirrhinus mrigala: efeitos sobre a composição corporal, atividade enzimática intestinal e parâmetros hematológicos

A ninety days nutritional trial was directed to explore the effects of dietary chromium on body composition, gut enzyme activity and physiological status of Cirrhinus mrigala by using G & NG corn. Six experimental diets were prepared by using different levels of chromium chloride hexahydrate (0, 0.2, 0.4 mg/kg, each with G & NG corn). For this experimental trial, 480 fingerlings, irrespective of sex were distributed in six aquariums each with replicate. Results revealed that gelatinized corn along with increasing level of Cr2Cl3.6H2O have a positive impact upon body composition of fish. Hematology was positively correlated with chromium chloride hexahydrate supplementation in gelatinized corn. Amylase gut enzyme also showed significant (P<0.05) increase in group fed with chromium chloride hexahydrate supplemented diet (G corn). However, corn with chromium chloride hexahydrate supplementation did not revealed any significant impact on gut protease enzyme activity. From these results it can be concluded that both chromium chloride hexahydrate and gelatinized corn in fish feed are very beneficial to improve body composition, enzymes activity and physiological health status of fish.

Um ensaio nutricional de 90 dias foi dirigido para explorar os efeitos do cromo dietético na composição corporal, atividade enzimática intestinal e estado fisiológico de Cirrhinus mrigala usando milho G & NG. Seis dietas experimentais foram preparadas usando diferentes níveis de cloreto de cromo hexa-hidratado (0, 0,2, 0,4 mg/kg, cada um com milho G e NG). Para este ensaio experimental, 480 alevinos, independentemente do sexo, foram distribuídos em seis aquários, cada um com réplicas. Os resultados revelaram que o milho gelatinizado, juntamente com o aumento do nível de Cr2Cl3.6H2O, tem um impacto positivo na composição corporal dos peixes. A hematologia foi positivamente correlacionada com a suplementação de cloreto de cromo hexa-hidratado em milho gelatinizado. A enzima amilase intestinal também apresentou aumento significativo (P <0,05) no grupo alimentado com dieta suplementada com cloreto de cromo hexa-hidratado (milho G). No entanto, o milho com suplementação de hexahidrato de cloreto de cromo não revelou nenhum impacto significativo na atividade da enzima protease intestinal. Desses resultados, pode-se concluir que tanto o cloreto de cromo hexa-hidratado quanto o milho gelatinizado na alimentação de peixes são muito benéficos para melhorar a composição corporal, a atividade de enzimas e o estado fisiológico de saúde dos peixes.

Impact of Hygrophila auriculata supplementary diets on the growth, survival, biochemical and haematological parameters in fingerlings of freshwater fish Cirrhinus mrigala (Hamilton, 1822).

The present study investigates the effects of Supplementary diet Hygrophila auriculata on the growth, survival, biochemical and haematological parameters of Cirrhinus mrigala. The seaweed was administered to the fish possessing an initial average weight of 14.063 ± 1.828 g. Fish were fed with supplementary diet H. auriculata exhibited significant difference (P < 0.05) in the growth performance, haematological indices such as RBC count, haematocrit volume, haemoglobin, WBC, MCV, MCH and MCHC concentration in contrast to the control after a period of 8 weeks. Also, there were significant differences in biochemical parameters (P < 0.05), between the fish supplemented with dietary H. auriculata extract and the control group. These findings suggest that the administration of H. auriculata extract has a positive effect on the immunological indices and the immune system activity in Mrigal fish.

Exogenous phytase and xylanase supplementation of formulated diets for rohu (Labeo rohita): impact on haematology, histology and IGF I gene expression.

The present study aims to delineate the effect of exogenous enzyme supplementation of fermented or non-fermented de-oiled rice bran (DORB) on haematology, histology and expression of IGF I gene expression of Labeo rohita. Four test diets, namely, T1 (DORB), T2 (fermented DORB), T3 (DORB+exogenous enzyme) and T4 (fermented DORB+exogenous enzyme) were formulated and fed to the L. rohita for a period of 60 days. The test diets T3 and T4 were supplemented with 0.1 g kg-1 xylanase (16,000 U kg-1) and 0.1 g kg-1 phytase (500 U kg-1) enzymes. A total of 120 juveniles of L. rohita (average weight 5.01 ± 0.02 g) were stocked in 12 rectangular tanks with 10 fish per tank in triplicates. At the end of the experiment, haematology, histology and IGF I gene expression of the different groups were analysed. The haemoglobin (Hb) content, RBC count and WBC count of L. rohita varied significantly (p < 0.05) among different groups. T3 diet-fed group had the highest Hb content, RBC count and WBC count as compared to the other groups. The MCV content was significantly (p < 0.05) lower in T3 group. The DORB type, exogenous enzyme supplementation and their interaction have no significant (p > 0.05) effect on MCH, MCHC and lymphocyte content of the cultured fish. The group which were fed T3 diet had significantly (p < 0.05) higher IGF-I gene expression as compared to other groups. The histological examination of liver revealed no pathological alteration of this organ. Similarly, there were no pathological changes observed in intestinal tissue in any dietary treatment group. Based on the findings of the present study, it is concluded that exogenous enzyme supplementation of DORB-based diets improves the physiological status and growth performances of Labeo rohita.

Effects of dietary α-linolenic acid/linoleic acid ratio on growth performance, tissue fatty acid profile, serum metabolites and Δ6 fad and elovl5 gene expression in silver barb (Puntius gonionotus).

BACKGROUND: Silver barb (Puntius gonionotus) is a medium-sized carp that is promising for freshwater aquaculture in Asia. This study's aim was to investigate the ideal dietary α-linolenic acid (ALA): linoleic acid (LA) ratio for maximizing long-chain polyunsaturated fatty acid (LC-PUFA) synthesis and their deposition in the muscle of silver barb, as that of fish oil based control diet. RESULT: Fish (with an initial body weight of 11.07 ± 0.12 g) were fed for 60 days with five experimental iso-proteinous, iso-lipidic, and iso-caloric diets, supplemented with linseed oil and peanut oil at varying levels to obtain ALA:LA ratios of 0.35, 0.51, 0.91, 2.04, 2.66. A control diet was prepared by supplementing fish oil. The dietary ALA:LA ratio did not influence the growth performance of fish. With increased dietary ALA:LA ratios, LA content decreased and ALA content increased in the muscle and liver of silver barb. The n-3 LC-PUFA level in muscle and liver was not influenced by feeding different ratios of ALA:LA, whereas n-6 LC-PUFA was decreased in the muscle and increased in the liver with increased dietary ALA:LA ratios. Increasing dietary ALA:LA ratio increased the Δ6fad and elovl5mRNA expression in the liver, muscle, brain, and intestinal tissues of silver barbs. CONCLUSION: Silver barb possess the ability to elongate and desaturate ALA and LA to their end products EPA and DHA. The highest level expression of Δ6 fad and elovl5 mRNA at the dietary ALA:LA ratio of 2.66 suggests greater affinity of these enzymes towards ALA than LA in silver barb. © 2019 Society of Chemical Industry.

Effects of dietary fenugreek seed extracts on growth performance, plasma biochemical parameters, lipid metabolism, Nrf2 antioxidant capacity and immune response of juvenile blunt snout bream (Megalobrama amblycephala).

Dietary administration of some plant-derived substances have been proved of great economic value in aquaculture. In order to investigate the effects of dietary fenugreek seed extracts (FSE) on juvenile blunt snout bream (Megalobrama amblycephala), a feeding trial was conducted for 8 weeks. The results showed that final weight (FW), weight gain (WG), feed conversion ratio (FCR) and specific growth rate (SGR) were not significantly affected by dietary FSE levels. The whole body lipid contents of fish fed with 0.04%, 0.08% and 0.16% FSE diets were significantly lowered compared to the control group. Dietary FSE diets significantly affected plasma complement component 3 (C3), immunoglobulin M (IgM), albumin (ALB) and total protein (TP). The relative expressions of acetyl CoA carboxylase (ACC), fatty acid synthase (FAS) and sterol regulatory element binding protein-1 (SREBP1) mRNA in the liver of fish decreased significantly with increasing dietary FSE levels from 0% up to 0.04%. FSE supplementation diets lowered the liver pro-inflammatory genes expressions by regulating tumor necrosis factor-α (TNF-α) and interleukin 8 (IL-8) mRNA levels and increased anti-inflammatory genes expression by regulating transforming growth factor (TGF-ß) and interleukin 10 (IL-10). FSE diets increased growth factor-1 (IGF-1) and target of rapamycin (TOR) mRNA levels from 0% up to 0.04%, 0.04% FSE diets significantly increased growth factor-1 (IGF-1) mRNA levels and S6 kinase-polypeptide 1 (S6K1) mRNA levels compared to the control group. 0.04% FSE diets significantly increased superoxide dismutase (SOD) activities and 0.08% FSE diets significantly increased catalase (CAT) and glutathione peroxidase (GPx) activities, 0.16% FSE diets significantly increased total antioxidant capacity (T-AOC) activities compared to the control group. Additionally, compared to the control group, 0.04% dietary FSE significantly up-regulated nuclear factor erythroid 2-related factor 2 (Nrf2) mRNA levels and glutathione peroxidase-1 (GPx1) mRNA levels, at the same time, 0.02%, 0.04%, 0.08%, 0.16% FSE diets significantly down-regulated kelch-like ECH-associated protein 1 (Keap1) mRNA levels. However, no significant effects were observed on copper zinc superoxide dismutase (Cu/Zn-SOD) and manganese superoxide dismutase (Mn-SOD). Our study indicated that dietary FSE could improve plasma biochemical parameters, regulate lipid metabolism related genes, promote Nrf2 antioxidant capacity and enhance immune response of juvenile blunt snout bream.

Serum biochemistry, liver histology and transcriptome profiling of bighead carp Aristichthys nobilis following different dietary protein levels.

Dietary protein plays a major role in determining the rate of fish growth and overall health. Given that the liver is an important organ for metabolism and detoxification, we hypothesized that optimal dietary protein levels may benefit liver function. Herein, we investigated the effects of dietary protein level on serum biochemistry, liver histology and transcriptome profiling of juvenile bighead carp Aristichthys nobilis fed for 8 weeks on a diet supplemented with high protein (HP, 40%), low protein (LP, 24%) or optimal protein (OP, 32%; controls). The results revealed a significant change in liver morphology in LP and HP groups compared with the OP group, coupled with increased serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activity. RNA sequencing (RNA-Seq) analysis of the liver transcriptome yielded 47 million high-quality reads using an Illumina platform, which were de novo assembled into 80,777 unique transcript fragments (unigenes) with an average length of 1021 bp. Subsequent bioinformatics analysis identified 878 and 733 differentially expressed unigenes (DEGs) in liver in response to LP and HP diets, respectively. KEGG enrichment analysis of DEGs identified immune and metabolism-related pathways, including Toll-like receptor signaling, PI3K-Akt signaling, NF-κB signaling, complement and coagulation, peroxisome, nitrogen metabolism, PPAR signaling, and glycolysis and gluconeogenesis pathways. Transcriptome profiling results were validated by quantitative real-time PCR for 16 selected DEGs. The findings expand our understanding of the molecular mechanisms underlying the effects of dietary protein level on liver function in bighead carp.

Evaluation of dietary Hybanthus enneaspermus (Linn F. Muell.) as a growth and haemato-immunological modulator in Labeo rohita.

This study evaluated the effects of Hybanthus enneaspermus aqueous extract (HEE) as a feed supplement on growth, immune responses, haematological, and biochemical parameters of Labeo rohita and its susceptibility to Aeromonas hydrophila infection. Diets containing five variable concentrations of HEE (g kg-1) (0 [basal diet], 1.0 [H1], 2.0 [H2], 3.0 [H3], and 4.0 [H4]) were fed to fish (average weight: 17.2 ± 0.21 g) for 6 weeks. Growth parameters, immune parameters, and haemato-biochemical parameters were examined 6 weeks post-feeding. The results showed that growth parameters, such as final weight (39.47 ± 3.1 g) and specific growth rate (1.92 ± 0.2), were significantly higher in the H3 group than in the control. Immunological parameters such as serum lysozyme (24.73 ± 2.16 U mg-1), phagocytic activity (19.14± 0.26%), and respiratory burst activity (0.307 ± 0.005) were significantly higher in the H3 group, compared with the control. Among the haematological parameters examined, red blood cells, white blood cells, neutrophils, total serum protein, and albumin levels were significantly higher in the H3 group. However, HEE administration had no significant effect on haematocrit, haemoglobin, monocytes, or eosinophils levels. Blood biochemical parameters, including superoxide dismutase and alkaline phosphatase activities, were higher (P < 0.05) in the H3 group than in the control; however, the opposite result was found for aspartate transaminase, alanine transaminase, glucose, and cholesterol. Supplementation with 3 g kg-1 HEE increased the activities of intestinal digestive enzyme (amylase, protease, and lipase) in fish. Moreover, fish fed diets supplemented with 3 g kg-1 HEE exhibited the highest disease resistance against A. hydrophila infection. These results suggest that dietary administration of HEE (at 3 g kg-1) has several positive effects on growth, immune and haematological responses in L. rohita.

Dietary supplementation with selenium yeast and tea polyphenols improve growth performance and nitrite tolerance of Wuchang bream (Megalobrama amblycephala).

In order to explore the effects of dietary selenium yeast, tea polyphenols and their combination on growth of Wuchang bream (Megalobrama amblycephala) and its resistance to nitrite stress, 360 healthy Wuchang bream with initial body weight of (55.90 ± 2.60) g were randomly divided into four groups: a control group fed with basal diet and three treated groups fed with basal diets supplemented with 0.50 mg/kg selenium yeast, 50 mg/kg tea polyphenols, and the combination of 0.50 mg/kg selenium yeast and 50 mg/kg tea polyphenols, respectively. After 60 d of feeding, the growth performance of Wuchang bream was measured. Then 25 fish per tank were exposed to nitrite stress of 15.0 mg/L. The serum stress hormones, liver histology and hepatic antioxidant responses were evaluated before nitrite exposure (0 h) and at 6, 12, 24, 48 and 96 h after exposure. The results showed that before nitrite exposure, compared with the control, the weight gain, specific growth rate, liver total antioxidant capacity, the activities and transcriptional levels of hepatic antioxidant enzymes (superoxide dismutase and glutathione peroxidase) in the selenium yeast and combination groups were significantly increased, while feed conversion rate was decreased significantly, which suggested that the combined use of selenium yeast and tea polyphenols as well as the single selenium yeast supplementation improved growth performance and enhanced antioxidant capacity in fish. After nitrite exposure, compared with the control, liver total antioxidant capacity as well as the activities and transcription levels of catalase superoxide dismutase and glutathione peroxidase in three treatment groups were significantly increased in varying degrees whereas serum cortisol contents and liver malondialdehyde levels were decreased significantly. By contrast, the combined use of selenium yeast and tea polyphenols was more effective than the single supplementation with selenium yeast or tea polyphenols. In consistent with this, alterations of the liver histostructure in three treatment groups were slower and less severe than in the control group after nitrite exposure. In conclusion, a basal diet supplemented with the combination of 0.50 mg/kg selenium yeast and 50 mg/kg tea polyphenols could effectively improve growth performance and nitrite resistance in Wuchang bream.

The effects of dietary oxidized konjac glucomannan and its acidolysis products on the immune response, expression of immune related genes and disease resistance of Schizothorax prenanti.

In the present study, KGM was degraded by H2O2 and HCl to obtain two products with different molecular weights: oxidized konjac glucomannan (OKGM, 4.7 × 10(5) Da) and low-molecular-weight oxidized konjac glucomannan (L-OKGM, 9.2 × 10(3) Da). The effects of the two OKGM products on IL-1ß, TNF-α, and TLR22 gene expression, and immune parameters and the resistance to Aeromonas hydrophila of Schizothorax prenanti were determined. The results showed that the lysozyme activity was significantly enhanced by the L-OKGM diets. The SOD activity was significantly increased by both OKGM and L-OKGM diets. The MDA level of fish fed the OKGM and L-OKGM diets was significantly lower than the control group. IL-1ß mRNA level in the spleen significantly increased in all L-OKGM fed groups. The 8.0 g kg(-1) L-OKGM diet also significantly up-regulated IL-1ß gene expression in the head kidney. In the gut, IL-1ß mRNA levels were significantly higher in fish fed with the 8.0 g kg(-1) OKGM and 16.0 g kg(-1) L-OKGM diets. The TNF-α mRNA level of L-OKGM group significantly increased in the spleen, head kidney and gut. High dosing of OKGM significantly up-regulated TNF-α transcription in the head kidney, while only the 8.0 g kg(-1) OKGM group showed significantly higher TNF-α mRNA expression in the mesonephros. Fish fed the L-OKGM diets showed significantly higher expression of TLR22 in the spleen, head kidney and mesonephros. After the injection of A. hydrophila, the 8.0 g kg(-1) L-OKGM group showed a significantly higher survival rate than did the control group. Present study suggests that OKGM and L-OKGM can up-regulate immune-related gene expression and enhance disease resistance in S. prenanti, and L-OKGM exhibits higher immunomodulatory activity.

Effects of dietary pyridoxine on haemato-immunological responses of Labeo rohita fingerlings reared at higher water temperature.

A sixty-day feeding trial was carried out to elucidate the effect of dietary pyridoxine (PN) on hemato-immunological parameters in Labeo rohita fingerlings exposed to an elevated temperature (ET) of 33 °C. Two hundred and seventy fingerlings (6.71 ± 0.32 g) were randomly distributed into six treatments in triplicates (15 fish/tank). Five iso-nitrogenous (356.3 ± 2.7 g/kg crude protein) purified diets were prepared with graded levels (0, 10, 50, 100 and 200 mg/kg diet) of PN. Six treatment groups were P10T26 (10 mg PN + ambient temperature (26 °C), P0T33 (0 mg PN + ET), P10T33 (10 mg PN + ET), P50T33 (50 mg PN + ET), P100T33 (100 mg PN + ET) and P200T33 (200 mg PN + ET). The responses of L. rohita fingerlings to dietary PN were assessed in terms of growth and by analysing some hemato-immunological parameters. When PN supplementation increased from 10 to 200 mg/kg diet, a significant improvement in weight gain percentage was observed. Erythrocyte (RBC) count, leucocyte (WBC) count, haemoglobin content and respiratory burst activity were significantly (p < 0.05) higher in 100 mg PN/kg diet-fed group than their non-PN-fed counterpart. Also, serum albumin, globulin and lysozyme activity were found significantly (p < 0.05) higher in PN-fed groups. The overall results indicated that dietary PN supplementation at 100 mg/kg diet may reverse the negative effects caused by ET and may protect the haemato-immunological status of L. rohita fingerlings reared at higher water temperature.

Yeast extract, brewer's yeast and spirulina in diets for Labeo rohita fingerlings affect haemato-immunological responses and survival following Aeromonas hydrophila challenge.

A feeding trial was conducted for 60 days to study the immunomodulatory role of three different immunostimulants yeast extract (YE), brewer's yeast (BY) and spirulina (SP) in Labeo rohita fingerlings. Four hundred and fifty fingerlings (avg. wt 3.35±0.15 g) were randomly distributed in ten treatments and fed with either of ten iso-nitrogenous and iso-caloric semi-purified diets, prepared with three incremental levels (1%, 2% and 4%) of different immunostimulants except the control. Growth parameters did not vary significantly (p>0.05) among the experimental groups. Haematology and serum parameters was performed before Aeromonas hydrophila challenge whereas respiratory burst activity was analysed following challenge. The respiratory burst activity, total leucocyte count, serum total protein and globulin was significantly higher (p<0.05) in YE 1% supplemented group. The survival (%) after challenging with A. hydrophila was also highest in the YE fed groups. The results indicate that among the different sources and levels of immunostimulants, YE at lower inclusion level is more effective in promoting the immune status of L. rohita fingerlings.

Biomonitoring of genotoxicity using micronuclei assay in native population of Astyanax jacuhiensis (Characiformes: Characidae) at sites under petrochemical influence.

Bom Jardim brook is a small stream that flows through an area under the influence of a Petrochemical Complex, demanding control over its quality, so a genotoxic evaluation was performed. This study was conducted in situ, based on previous analysis on the same subject. These were performed both in vitro, with Salmonella typhimurium and human lymphocytes, and in vivo, using bioassays with fish exposed to water from the study area. The purpose of this research was to assess the quality of the aquatic environment and possible effects from petrochemical pollution to surrounding native populations. Micronuclei (MNE) and nuclear abnormalities (NA) frequencies in peripheral blood of Astyanax jacuhiensis, a native fish species collected from the study area, were used as biomarkers. Study period was from summer/99 to spring/2001, using samples obtained seasonally at two ponds upstream from the industrial area (BJN and BJPa) and two sites in Bom Jardim brook (BJ002 and BJ000), which are subject to Complex influence. MNE and NA frequencies found in individuals from BJ002 and BJ000 were similar, showing positive genotoxic responses related to control sites BJN and BJPa. No differential sensitivity could be verified for micronuclei induction between genders of A. jacuhiensis in the studied population. This study showed that sites subject to petrochemical influence were under higher genotoxic impact. Biomarkers adequacy to the case and the sensitivity of A. jacuhiensis for water monitoring could be also inferred.