Influence of taurine on the zootechnical performance and health parameters of juvenile Nile tilapia in a recirculating aquaculture system.

Taurine is considered a conditionally essential amino acid for fish, so its supplementation may improve feed conversion. This study evaluated the supplementation of taurine on growth performance, hematological and immunological parameters, production costs, and survival of Nile tilapia (Oreochromis niloticus) juveniles raised in a recirculating aquaculture system (RAS). A control diet was formulated with 360 g kg-1 of crude protein without fish meal and without taurine supplementation (Control). From the control diet, another diet supplemented with 9.7 g of taurine per kg of feed (Taurine) was produced. Fish fed diet supplemented with taurine had lower daily average weight gain and final average weight compared to the control diet (p < 0.05). It was observed that taurine had no influence on condition factor, survival, or hemato-immunological parameters of Nile tilapia juveniles, but there was a higher mean corpuscular volume and greater nitrogen retention in fish from the control group (p < 0.05). It is concluded that Nile tilapia juveniles do not benefit from taurine supplementation in RAS, even when fed diet containing plant-based protein sources.

Autochthonous and allochthonous lactic acid bacteria: action on the hematological and intestinal microbiota for two species of Astyanax genus.

The objective of this work was to evaluate the effect of autochthonous and allochthonous lactic acid bacteria (LAB) in two species of lambaris (Astyanax bimaculatus and Astyanax fasciatus), and to investigate the effects on intestinal microbiota and hematological changes. Two experiments were carried out, one for each lambari species, both assays were divided into three treatments: autochthonous LAB, allochthonous LAB and control. The 10% inoculum was included on diet in the LAB treatments and sterile medium for control. After 30 days for A. bimaculatus LAB indigenous changes all bacteria groups analyzed, while allochthonous LAB just decrease Staphylococcus spp. count. Though for A. fasciatus his autochthone LAB reduced the staphylococcal count. In hematology, for A. bimaculatus autochthonous LAB showed a higher number of thrombocytes, lymphocytes, monocytes and total leukocytes in the circulatory system than the control. Though for A. fasciatus his autochthone LAB showed a higher number of total lymphocytes and leukocytes than the control, while Lactobacillus sp. acting as an allochthone, it did not differ among treatments. In conclusion, both LAB (Lactobacillus sp. and L. lactis) promoted more beneficial changes in the microbiota and hematological profile when they act as an autochthone probiotic, demonstrating a probiotic-associated host.

Curcuma longa hydrolate improves Nile tilapia survival in a recirculation rearing system, maintaining the animal homeostasis and modulating the gut microbial community.

This study aimed to evaluate the effects of the dietary supplementation Curcuma longa hydrolate on Nile tilapia (Oreochromis niloticus) reared in a recirculation system. Hemato-immunological parameters, growth performance, nitrogen and phosphorus retention, as well as body composition and its interaction with the intestinal microbiota, were studied. Nile tilapia fingerlings (120) were distributed randomly in 8 polyethylene tanks (40 L). The experimental units were divided into two treatments, in quadruplicate: commercial diet supplemented with 2.5% of C. longa hydrolate and commercial diet without supplementation (control). After 45 days, the treatment supplemented hydrolate showed higher survival than the control group, 95.25% and 82.22%, receptively. In the blood profile, fish supplemented with hydrolate had a higher count of total leukocytes and neutrophils, as well as mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration, than control group. The hydrolate group showed a substantial increase in the relative abundance of Cetobacterium and Romboutsia, as well as lower diversity in gut microbiota. The dietary addition of C. longa hydrolate for Nile tilapia seems to have a beneficial effect on gut microbiota, in addition to a likely positive effect on the physiological performance of Nile tilapia by maintaining intestinal homeostasis and promoting survival in reared conditions.

Induced aerocystitis and hemato-immunological parameters in Nile tilapia fed supplemented diet with essential oil of Lippia alba / Aerocistite induzida e parâmetros hemato-imunológicos em tilápia do Nilo suplementada com óleo essencial de Lippia alba

The present study evaluated the dietary supplementation with essential oil of Lippia alba on the hemato-immunological parameters of Nile tilapia (Oreochromis niloticus) submitted to acute inflammation induced by carrageenin injection in the swim bladder. For a period of 45 days, 96 fish were divided in four treatments in triplicate, as follows: fish fed supplemented diet with essential oil of L. alba (4 mL kg-1 dry ration) injected with carrageenin; fish fed supplemented diet with cereal alcohol injected with carrageenin; fish fed unsupplemented diet with essential oil injected with carrageenin; fish fed unsupplemented diet and noninjected. Cortisol levels, erythrogram, leukogram and the inflammatory infiltrate were analyzed 6 h after inflammatory stimulus. Carrageenin-injected fish showed acute inflammatory reaction in the swim bladder characterized by higher infiltrate of neutrophils and monocytes. The circulating neutrophils number was significantly higher in fish fed L. alba when compared to other treatments. No difference in cortisol levels was found. For dose, time and administration form tested, supplementation with essential oil of L. alba did not present anti-inflammatory activity. On the other hand, influence of dietary supplementation was observed on the neutrophils number after induced aerocystitis highlighting its immunomodulatory characteristic.(AU)

O presente estudo avaliou a suplementação dietária com óleo essencial de Lippia alba sobre os parâmetros hemato-imunológicos em tilápias do Nilo (Oreochromis niloticus) submetidas à inflamação aguda induzida por carragenina na bexiga natatória. Pelo período de 45 dias, 96 peixes foram divididos em quarto tratamentos em triplicata: a) peixes suplementados com óleo esencial de L. alba (4 mL kg-1 de ração) injetados com carragenina; b) peixes suplementados com álcool de cereais injetados com carragenina; peixes não suplementados com óleo essencial injetados com carragenina; c) peixes não suplementados não injetados. Os níveis de cortisol, eritrograma, leucograma e o infiltrado inflamatório foram analisados seis horas após o estímulo inflamatório. Peixes injetados com carragenina apresentaram reação inflamatória aguda na bexiga natatória caracterizada por maior infiltrado de neutrófilos e monócitos. O número de neutrófilos circulantes foi significativamente maior nos peixes suplementados com L. alba quando comparado aos outros tratamentos. Não houve diferença nos níveis de cortisol. Para a dose, o tempo e a forma de administração testada, a suplementação com óleo essencil de L. alba não apresentou atividade anti-inflamatória. Por outro lado, foi constatada influência da suplementação dietária no número de neutrófilos após a aerocistite enfatizando a sua característica imunomoduladora.(AU)

Frequency in the supply of Lactobacillus influence its probiotic effect for yellow tail lambari / Frequência no fornecimento de Lactobacillus influencia seu efeito probiótico para o ambari-do-rabo-amarelo

ABSTRACT: The aim of this research was to evaluate the changes in intestinal tract microbiota, hematological parameters and zootechnical indexes of yellowtail lambaris (Astyanax bimaculatus) fed with different probiotic supply frequencies (Lactobacillus spp.). Lambaris (1,200) were distributed in twelve boxes, divided in three treatments, 100% supply; 25% and 0% (control) of feeds supplemented with probiotic. After 87 days, fish fed with supplemented diet, regardless of frequency (100% and 25%), showed an increase in the total lactic acid bacteria count of 7.99±0.15 log CFU mL-1 and 7.04±1, 29 log UFC mL-¹ respectively, in the intestinal tract and decrease of Pseudomonas spp. in both 100% and 25% (4.09±0.84log UFC mL-1 and 4.00±1.12log UFC mL-1, respectively) in relation to the control treatment (6.74±1.04log UFC mL-1). Fish fed with 100% of diets supplemented with probiotics had a higher leukocyte count (47.7±6.7x103μL-1), lymphocytes (36.0±2.6x103μL1), monocytes (12.0±4.2x103μl-1), as well as higher mean final weight (10.60±0.89g) and weekly growth rate (0.80±0.08g.week-1) than the other treatments (25% of probiotic offered and control). Probiotic (Lactobacillus spp.) offered in 25% of feeds (or more) alters the yellowtail lambari microbiota (A. bimaculatus); however, must be offer in 100% of feeds to improve the hematology profile and productive performance.

RESUMO: O objetivo deste trabalho foi avaliar as alterações na microbiota do trato intestinal, parâmetros hematológicos e índices zootécnicos de lambaris-do-rabo-amarelo (Astyanax bimaculatus) alimentados com diferentes frequências de oferta do probiótico (Lactobacillus spp.). Os lambaris (1.200) foram distribuídos em doze caixas, divididos em três tratamentos, oferta de 100%, 25% e 0% (controle) de alimentações suplementadas com probiótico. Após 87 dias, os peixes alimentados com dieta suplementada, independente da frequência (100% e 25%), apresentaram aumento na contagem total de bactérias ácido láticas 7,99±0,15log UFC mL-¹ e -7,04±1,29log UFC mL-¹, respectivamente, no trato intestinal e redução de Pseudomonas spp. tanto em 100% quanto em 25% (4,09 ± 0,84 log UFC mL-¹ e 4,00±1,12 log UFC mL-¹, respectivamente) em relação ao tratamento controle (6,74±1,04log UFC mL-¹). Os peixes alimentados com 100% das dietas suplementadas com probiótico apresentaram maior contagem de leucócitos (47,7±6,7x103µL-1), linfócitos (36,0±2,6x103µL-1), monócitos (12,0±4,2x103µL-1), assim como maior peso médio final (10,60±0,89g) e taxa de crescimento semanal (0,80±0,08g.semana-1) que os demais tratamentos (25% de oferta de probiótico e controle). O probiótico (Lactobacillus spp.) oferecido em 25% de alimentos (ou mais) altera a microbiota de lambari de rabo amarelo (A. bimaculatus), no entanto, deve ser oferecido em 100% de alimentos para melhorar o perfil hematologia e desempenho produtivo.

Immunization of hybrid surubim (Pseudoplatystoma corruscans x P. fasciatum) against Motile Aeromonas hydrophila septicemia

The aim of this study was to evaluate the immune response of hybrid surubim vaccinated by intraperitoneal injection and by immersion against Aeromonas hydrophila. Vaccine was prepared with formalin-inactivated A. hydrophila. Forty eight fishes (47±9g) were distributed in 12 tanks (4 fish / tank) in the following treatments (4 tanks / treatment): unvaccinated fish, vaccinated intraperitoneally and vaccinated by immersion. After 21 days, intraperitoneally vaccinated fishes showed the highest values of total protein and immunoglobulins, agglutination titer and serum antimicrobial activity. Lysozyme concentration in the serum was higher in the fishes vaccinated by immersion than unvaccinated fishes. Intraperitoneal vaccination induced the highest immune response and could be used to improve the fish resistance against motile Aeromonas.

Cultivation of juvenile fat snook (Centropomus parallelus Poey, 1860) fed probiotic in laboratory conditions

The objective of this study was to investigate the growth of juvenile fat snook (Centropomus parallelus) in laboratory conditions when fed a diet supplemented with the probiotic Lactobacillus plantarum. Changes in the intestinal flora, haematological parameters and growth performance were assessed using 180 fishes (54.2 ± 13.4 g each). The fishes were subjected to two treatments divided into six cages: 1) feed supplemented with probiotic, and 2) feed without probiotic (control). The temperature, dissolved oxygen and salinity were maintained at 25 ± 1 ° C, 4.0 mg.L-1 and 33 ‰, respectively. After 10 weeks of culture, the fishes fed probiotic had reduced viable culturable heterotrophic bacteria and Vibrio spp. and increased lactic acid bacteria in the intestinal tract, as well as a higher number of thrombocytes, leukocytes and lymphocytes in the blood. No significant difference was observed in the growth, survival or body composition, but the hepatosomatic index was significantly higher in the fishes fed with probiotic and control.

Acute inflammatory response in Nile tilapia fed probiotic Lactobacillus plantarum in the diet / Resposta inflamatória aguda em tilápia do Nilo alimentada com probiótico, Lactobacillus plantarum na dieta

The present study evaluated the acute inflammatory response induced by carrageenin (500 µg) injected in the swim bladder of Nile tilapia, after fed or not probiotic supplemented diet. Fifty four fish were distributed in six treatments and three replicates: Group A: Fish fed unsupplemented diet: 0.5 mL saline-injected fish; fish injected with 500 µg carrageenin diluted in 0.5 mL saline; Non-injected. Group B: Fish fed probiotic supplemented diet: saline-injected fish; carrageenin-injected fish; Non-injected. Fifteen days after feeding the fish were injected with carrageenin or saline. After six hours, inflammatory exudate was collected, as well as the blood for hematocrit, red blood cell (RBC) and white blood cell (WBC) counts, differential count of leucocytes and phagocytic activity in the blood. Supplementation with probiotic did not influence the RBC, hematocrit and the numbers of lymphocytes and basophils in the blood. The number of neutrophils was significantly higher in supplemented fish injected with carrageenin. Glucose concentration in supplemented and non-injected fish was higher than that observed in the saline injected ones. Probiotic potentialized the migration of cells to the inflammatory focus in the animals injected with the carrageenin irritant. In fish injected with saline and carrageenin occurred the greatest phagocytic activity in the blood in relation to those treatments.

Este trabalho avaliou a resposta inflamatória aguda induzida por injeção de carragenina (500 g) na bexiga natatória de tilápia do Nilo suplementada ou não com probiótico na ração. Cinquenta e quatro animais foram distribuídos em seis tratamentos com três repetições: Grupo A: peixes alimentados com ração não-suplementada: Controle (injeção de 0,5 mL de solução salina estéril); Carragenina (injeção de 500 µg de carragenina); Não-injetada. Grupo B: peixes alimentados com ração suplementada com probiótico: Controle; Carragenina; Não-injetada. Após 15 dias de alimentação foi injetado carragenina ou salina. Após 6h, realizou-se a coleta de exsudato e sangue para determinação do hematócrito, contagens totais de eritrócitos, leucócitos, contagem diferencial de leucócitos e atividade fagocitária no sangue. A suplementação com probiótico na ração não influenciou o número total de eritrócitos, o hematócrito e os números de linfócitos e basófilos no sangue dos animais. O número de neutrófilos foi maior nos peixes suplementados com probiótico e injetados com carragenina. A glicose nos peixes suplementados com probiótico não-injetados foi maior do que nos injetados com salina. A suplementação com probiótico potencializou a migração de células para o foco inflamatório nos injetados com o flogógeno carragenina. Em peixes injetados com salina e carragenina, ocorreu maior atividade fagocitária no sangue em relação aos demais tratamentos.

Diet supplemented with probiotic for Nile tilapia in polyculture system with marine shrimp.

The aim of this study was to assess the effect of a probiotic (Lactobacillus plantarum) supplemented diet on Nile tilapia (Oreochromis niloticus) in a polyculture system with marine shrimp (Litopenaeus vannamei) as regards culture performance, hematology, and gut bacterial microbiota. Ten 20-m² pens were arranged in one earthen pond and stocked with 2 fish (41.9 g) m(-2) and 10 shrimp (2.3 g) m(-2), in total of 40 Nile tilapias and 200 shrimp per experimental unit. Tilapia groups in five of the experimental units were fed a commercial diet supplemented with L. plantarum and the other five with an unsupplemented commercial diet (control). After 12 weeks of culture, the tilapia groups fed the probiotic-supplemented diet presented values 13.6, 7.5, and 7.1% higher for feed efficiency, yield, and final weight, respectively. Viable culturable heterotrophic bacteria counts were reduced, and the number of lactic acid bacteria was increased in the gut of fish and shrimp fed the probiotic-supplemented diet. Hematological analyses showed higher number of thrombocytes and leukocytes in tilapia fed the supplemented diet. L. plantarum utilized in this study colonized the gut of tilapia and shrimp and resulted in reduced number of total bacteria and increased tilapia final weight and feed efficiency.

Hematological and immunological responses of Nile tilapia after polyvalent vaccine administration by different routes / Resposta hematológica e imunológica de tilápia do Nilo após administração de vacina polivalente por diferentes vias

The efficacy of a polyvalent bacterin vaccine against Aeromonas hydrophila, Pseudomonas aeroginosa and Enterococcus durans administered by different routes in Nile tilapia was assessed by analyzing hematological and immunological parameters 7 and 21 days after vaccination. Treatments consisted of: non-vaccinated tilapia; tilapia vaccinated by intraperitoneal injection with 2x10(8) formalin-inactivated bacteriaÀmL-1; tilapia vaccinated orally with 2x10(7) formalin-inactivated bacteriaÀg-1, feed for 5 days; tilapia vaccinated by immersion bath in 2x10(7) formalin-inactivated bacteriaÀmL-1, for 20 minutes. Vaccinated fish groups presented higher hematocrit, number of erythrocytes and leukocytes than the non-vaccinated group. Serum agglutination titer of intraperitoneally vaccinated fish was higher on both evaluation periods for the three bacteria strains. Only on day 21 post-vaccination fish from the oral and immersion vaccination groups presented higher serum agglutination titer than the non-vaccinated fish for A. hidrophyla and E. durans. Serum antimicrobial activity in vaccinated fish was higher for P. aeroginosa and E. coli than in non-vaccinated fish on both evaluation periods. The different vaccine administration routes stimulated hematological and immunological responses in Nile tilapia 21 days post-vaccination, but intraperitoneal vaccination presented higher total number of leukocytes, lymphocytes and serum agglutination titer.

Este estudo avaliou a eficácia da administração de vacina polivalente (bacterina), contra Aeromonas hydrophila, Pseudomonas aeroginosa e Enterococcus durans, por diferentes vias de aplicação em tilápia do Nilo, analisando parâmetros hematológicos e imunológicos no 7º e 21º dia após vacinação. Os tratamentos consistiram de: tilápias não vacinadas; tilápias vacinadas via injeção intraperitoneal (i.p.) contendo 2x10(8) bactérias inativadasÀmL-1; tilápias alimentadas com ração contendo vacina na proporção de 2x10(7) bactérias inativadasÀg-1, durante 5 dias; tilápias vacinadas por banho de imersão em 2x10(7) bactérias inativadasÀmL-1, durante 20 minutos. Os peixes vacinados apresentaram maior porcentagem de hematócrito, número de eritrócitos e leucócitos durante o período do experimento, em relação aos não vacinados. O título de aglutinação do soro dos peixes vacinados intraperitonealmente foi superior nos dois períodos de avaliação para todas as bactérias. Apenas no 21º dia os peixes vacinados oralmente e por imersão apresentaram título de aglutinação superior aos peixes não vacinados para A. hidrophyla e E. durans. O soro dos peixes vacinados apresentou maior atividade antimicrobiana para P. aeroginosa e E. coli, do que os peixes não vacinados, nos dois períodos. As diferentes vias de administração da vacina estimularam a resposta hematológica e imunológica da tilápia do Nilo após 21 dias de vacinadas, sendo que o número total de leucócitos, linfócitos, título aglutinante do soro dos vacinados i.p. foi maior do que os demais.