Effects of dietary supplementation with inactivated Lactobacillus plantarum on growth performance, haemato-biochemical parameters, liver fatty acids profile and intestinal microbiome of Nile tilapia.

This study investigated the effects of dietary supplementation with inactivated Lactobacillus plantarum for Nile tilapia (Oreochromis niloticus). Three treatments, in quintuplicate, were established: a control group, fish fed a diet without additives; LP group, fish fed a diet supplemented with live probiotic; and IP group, fish fed a diet supplemented with inactivated probiotic. Final weights (49.40 ± 3.15 g) and weight gains (38.20 ± 3.23 g) were increased in tilapia in the IP group. Feed conversion (1.32 ± 0.04) decreased significantly in the IP group. Haemato-biochemical parameters were significantly influenced by dietary supplementation. Erythrocyte count (262.74 ± 69.28 × 106 µL-1) was significantly low, while albumin (1.79 ± 1.12 g dL-1) and cholesterol (254.14 ± 98.49 mg dL-1) were high in the control group. Dietary supplementation modified the tilapia microbiome. Rhodobacter was abundant in fish intestines from the control and IP groups. Phreatobacter was abundant in the IP and LP groups, while Aurantimicrobium and Bosea were abundant in the LP group. Oleic acid (C18:1n9) was significantly increased in the LP (3.25 ± 0.49%) and IP (3.02 ± 0.30%) groups. Hexadecatrienoic acid (C16:3n4) was significantly increased (0.04 ± 0.01%) in the IP group, while Cis 11,14,17-eicosatrienoic acid (C20:3n3) (0.31 ± 0.03%) and adrenic acid (C22:4n6) (0.11 ± 0.02%) were significantly decreased in the LP group. Additionally, monounsaturated fatty acids (MUFA) were significantly increased (4.83 ± 0.35%) in the LP group compared to that in the control group. Collectively, these results indicate the potential of inactivated L. plantarum for use in commercial feed, leading to the conclusion that both inactivated and live L. plantarum can improve the Nile tilapia metabolism, altering haematological and biochemical markers.

Impact of reference diet composition on apparent digestibility coefficients of two protein-rich ingredients in Nile tilapia

Protein quality is related to amino acid composition and digestibility. Accurate evaluation of apparent digestibility coefficients (ADCs) of nutrients in commonly used feedstuffs is paramount for formulating efficient aquafeed. ADCs of soybean meal (SBM) and poultry by-product meal (PBM) were evaluated using reference diets formulated with two types of ingredients (semi-purified [SP] and practical [P]) for juvenile Nile tilapia ( Oreochromis niloticus, Linnaeus) of the GIFT strain. Groups of 20 juveniles (65.05 ± 12.37 g) were fed twice a day to apparent satiety with one of the four experimental diets (SBM-SP, SBM-P, PBM-SP, and PBM-P) in quadruplicate for 30 days. After the last feeding, feces were collected by siphoning hourly and the ADCs of dry matter, protein, and amino acids (AAs) were calculated. Nile tilapia exhibited a high capacity to digest SBM and PBM, with most ADCs exceeding 90 %. The type of reference diet affected the ADCs of protein and AAs on the test ingredients, with the SP reference diet providing the highest ADC, mainly in SBM. Digestibility data generated with a P-type reference diet demonstrated more practical relevance than those generated with an SP-type reference diet. They can be applied in digestibility studies for Nile tilapia.(AU)

Oxidative damage in Nile tilapia, Oreochromis niloticus, is mainly induced by water temperature variation rather than Aurantiochytrium sp. meal dietary supplementation.

We investigated whether dietary supplementation with Aurantiochytrium sp. meal, a DHA-rich source (docosahexaenoic acid, 22: 6 n-3), fed during long-term exposure to cold-suboptimal temperature (22 °C, P1), followed by short-term exposure to higher temperatures (28 °C, P2, and 33 °C, P3), would promote oxidative damage in Nile tilapia (Oreochromis niloticus). Two supplementation levels were tested: 1.0 g 100 g-1 (D1) and 4.0 g 100 g-1 (D4). A control diet, without the additive (D0, 0 g 100 g-1), and a positive control diet supplemented with cod liver oil (CLO) were also tested. The concentrations of DHA and total n-3 PUFAs in the CLO diet were similar to those found in diets D1 and D4, respectively. The parameters analyzed included hemoglobin (Hb), the antioxidant enzymes catalase, glutathione peroxidase, total glutathione, non-protein thiols, and the oxidative markers protein carbonyl and erythrocyte DNA damage. Nile tilapia did not present differences in Hb content, regardless of diet composition, but the temperature increase (P1 to P2) led to a higher Hb content. Likewise, the temperature increases promoted alterations in all antioxidant enzymes. The dietary supplementation with 1.0 g 100 g-1 Aurantiochytrium sp. meal after P1 caused minor DNA damage in Nile tilapia, demonstrating that the additive can safely be included in winter diets, despite its high DHA concentration.

Dietary supplementation with increasing doses of an organic micromineral complex on juvenile Nile tilapia: Effects on the antioxidant defense system and tissue deposition.

The effect of increasing amounts (0%, 25%, 50%, 75%, and 100%) of dietary supplementation with an organic micromineral complex (Fe, Zn, Cu, Mn, and Se) on antioxidant defenses and mineral deposition in tissues of Nile tilapia juveniles was evaluated, where 100% supplementation represented the average adopted by the feed industry in Brazil. Fish (initial weight 23.93 ± 0.80 g) were fed until apparent satiation twice a day for 56 days. The maximum deposition of Fe and Zn in the hepatopancreas occurred in fish given approximately 50% supplementation, whereas the deposition of Mn and Se increased linearly with the inclusion of the complex. The activity of catalase and superoxide dismutase in the hepatopancreas decreased in fish fed the 50% dose, when compared to those not receiving mineral supplementation or those receiving higher doses. Glutathione peroxidase (GPx) activity in the hepatopancreas increased as the dietary Se concentration increased. However, the concentration of metallothionein in the hepatopancreas showed an inverse relationship to the increase in dietary supplementation of the organic mineral complex. There was no relationship between the doses of organic micromineral supplementation and the activities of GPx, reduced glutathione, non-protein thiols, or protein carbonylation. However, diets supplemented with 50% to 100% promoted greater GPx activity when compared to the 0% supplemented diet. Supplementation with intermediate doses of organic microminerals, approximately 50% of that used in commercial tilapia diets, promoted the homeostasis of metal metabolism, especially for Fe and Zn.

Protein requirement for initial rearing phase of pacific white shrimp in biofloc system / Exigência proteica para a fase inicial do camarão-branco-do-pácífico em sistema de bioflocos

This study evaluated the protein requirement of Litopenaeus vannamei post-larvae during the initial rearing phase in a biofloc system. Five different diets were evaluated with increasing concentrations of crude protein: 31.28, 36.29, 41.57, 46.34, and 51.74 g 100 g-¹ CP. Post-larvae (0.16 ± 0.01 g) were stocked at a density of 450 PL m-³ in 400 L tanks. Water quality parameters were maintained within the limits recommended for shrimp farming. After 38 days, a regression analysis revealed that levels of CP content (65.29–72.83%), EE (10.45–11.65%) and body N (10.45–11.64%) increased with increasing protein levels in the diet. A similar trend was observed in the biofloc sludge with respect to CP and N. Survival exceeded 80%, and the shrimp with diets containing 31.28 to 46.34 g 100 g-¹ CP presented an increase in final weight (1.52–2.61 g), productivity (0.69–1.10 kg m-³), weight gain (1.38–2.44 g), and feeding efficiency (77.28–101.68%), whereas these indices decreased to 51.74 g 100 g-¹ CP. Crude protein content from 44.26 to 47.12 g 100 g-¹ provided the best growth performance during the initial rearing phase of Pacific white shrimp L. vannamei in a biofloc system.

Esse estudo avaliou a exigência proteica do Litopenaeus vannamei na fase inicial de cultivo em sistema de bioflocos. Cinco dietas com quantidades crescentes de proteína bruta (31,28; 36,29; 41,57; 46,34 e 51,74 g 100 g-¹ PB) foram avaliadas. As pós-larvas (0,16 ± 0,01 g) foram estocadas na densidade de 450 PL m-³ em tanques de 400 L. A qualidade de água manteve-se dentro dos limites adequados para o cultivo. Após 38 dias, uma análise de regressão revelou que teores de PB (65,29–72,83%), EE (10,45–11,65%) e N corporal (10,45–11,64%) aumentaram com os níveis crescente de proteína na dieta. A mesma análise foi realizada para o lodo do bioflocos, que apresentou aumento crescente de PB e N. A sobrevivência foi superior a 80% e os camarões alimentados com dietas contendo 31,28 à 46,34g 100 g-¹ PB obtiveram aumento no peso final (1,52–2,61 g), produtividade (0,69–1,10 kg m-³), ganho em peso (1,38–2,44 g) e eficiência alimentar (77,28–101,68%), enquanto esses índices decresceram no tratamento 51,74 g 100 g-¹ PB. O conteúdo de proteína bruta entre 44,26 à 47,12 g 100 g-¹ PB proporcionou o melhor desempenho de crescimento durante a fase inicial do cultivo do camarão-branco-do-pacífico L. vannamei em bioflocos.

Protein to energy ratios and cost, performance, and ammonia excretion in juvenile jundiá (Rhamdia quelen), South American catfish

ABSTRACT: The determination of nutritional requirements, based on diets administered in practice, considers physiological specificities and sustainability are essential to the development of suitable aquaculture technologies for novel fish species. The growth of jundiá (Rhamdia quelen Quoy and Gaimard) juveniles (31.54 ± 4.92 g) fed five diets comprising increasing levels of digestible protein (DP: 24, 29, 34, 39, and 44 %) and digestible energy (DE: 12.13, 13.39, 13.81, 14.64, and 15.06 MJ kg1) with DP:DE ratios: 20, 22, 25, 27, and 29 g MJ1, respectively, was evaluated. Each diet was fed to three groups of 25 fish for 75 days. Regression analysis showed that the different DP:DE ratios affected both growth and economic performance as well as excretion of total ammonia nitrogen. Fish fed diets with DP:DE ratios between 22 and 27 g MJ1 achieved a higher daily weight gain, superior apparent net protein utilization, feed conversion rates, and lower feed costs. For the economically viable and environmentally friendly farming of jundiá juveniles in the initial growout stage (30 to 80 g average weight), the best DP:DE ratio was 25 g MJ1 DP:DE (34.05 % DP and 13.81 MJ kg1 DE).

Protein to energy ratios and cost, performance, and ammonia excretion in juvenile jundiá (Rhamdia quelen), South American catfish

The determination of nutritional requirements, based on diets administered in practice, considers physiological specificities and sustainability are essential to the development of suitable aquaculture technologies for novel fish species. The growth of jundiá (Rhamdia quelen Quoy and Gaimard) juveniles (31.54 ± 4.92 g) fed five diets comprising increasing levels of digestible protein (DP: 24, 29, 34, 39, and 44 %) and digestible energy (DE: 12.13, 13.39, 13.81, 14.64, and 15.06 MJ kg−1) with DP:DE ratios: 20, 22, 25, 27, and 29 g MJ−1, respectively, was evaluated. Each diet was fed to three groups of 25 fish for 75 days. Regression analysis showed that the different DP:DE ratios affected both growth and economic performance as well as excretion of total ammonia nitrogen. Fish fed diets with DP:DE ratios between 22 and 27 g MJ−1 achieved a higher daily weight gain, superior apparent net protein utilization, feed conversion rates, and lower feed costs. For the economically viable and environmentally friendly farming of jundiá juveniles in the initial grow–out stage (30 to 80 g average weight), the best DP:DE ratio was 25 g MJ−1 DP:DE (34.05 % DP and 13.81 MJ kg−1 DE).

Protein to energy ratios and cost, performance, and ammonia excretion in juvenile jundiá (Rhamdia quelen), South American catfish

The determination of nutritional requirements, based on diets administered in practice, considers physiological specificities and sustainability are essential to the development of suitable aquaculture technologies for novel fish species. The growth of jundiá (Rhamdia quelen Quoy and Gaimard) juveniles (31.54 ± 4.92 g) fed five diets comprising increasing levels of digestible protein (DP: 24, 29, 34, 39, and 44 %) and digestible energy (DE: 12.13, 13.39, 13.81, 14.64, and 15.06 MJ kg−1) with DP:DE ratios: 20, 22, 25, 27, and 29 g MJ−1, respectively, was evaluated. Each diet was fed to three groups of 25 fish for 75 days. Regression analysis showed that the different DP:DE ratios affected both growth and economic performance as well as excretion of total ammonia nitrogen. Fish fed diets with DP:DE ratios between 22 and 27 g MJ−1 achieved a higher daily weight gain, superior apparent net protein utilization, feed conversion rates, and lower feed costs. For the economically viable and environmentally friendly farming of jundiá juveniles in the initial grow–out stage (30 to 80 g average weight), the best DP:DE ratio was 25 g MJ−1 DP:DE (34.05 % DP and 13.81 MJ kg−1 DE).(AU)

Protein requirement for initial rearing phase of pacific white shrimp in biofloc system / Exigência proteica para a fase inicial do camarão-branco-do-pácífico em sistema de bioflocos

This study evaluated the protein requirement of Litopenaeus vannamei post-larvae during the initial rearing phase in a biofloc system. Five different diets were evaluated with increasing concentrations of crude protein: 31.28, 36.29, 41.57, 46.34, and 51.74 g 100 g-¹ CP. Post-larvae (0.16 ± 0.01 g) were stocked at a density of 450 PL m-³ in 400 L tanks. Water quality parameters were maintained within the limits recommended for shrimp farming. After 38 days, a regression analysis revealed that levels of CP content (65.29–72.83%), EE (10.45–11.65%) and body N (10.45–11.64%) increased with increasing protein levels in the diet. A similar trend was observed in the biofloc sludge with respect to CP and N. Survival exceeded 80%, and the shrimp with diets containing 31.28 to 46.34 g 100 g-¹ CP presented an increase in final weight (1.52–2.61 g), productivity (0.69–1.10 kg m-³), weight gain (1.38–2.44 g), and feeding efficiency (77.28–101.68%), whereas these indices decreased to 51.74 g 100 g-¹ CP. Crude protein content from 44.26 to 47.12 g 100 g-¹ provided the best growth performance during the initial rearing phase of Pacific white shrimp L. vannamei in a biofloc system.(AU)

Esse estudo avaliou a exigência proteica do Litopenaeus vannamei na fase inicial de cultivo em sistema de bioflocos. Cinco dietas com quantidades crescentes de proteína bruta (31,28; 36,29; 41,57; 46,34 e 51,74 g 100 g-¹ PB) foram avaliadas. As pós-larvas (0,16 ± 0,01 g) foram estocadas na densidade de 450 PL m-³ em tanques de 400 L. A qualidade de água manteve-se dentro dos limites adequados para o cultivo. Após 38 dias, uma análise de regressão revelou que teores de PB (65,29–72,83%), EE (10,45–11,65%) e N corporal (10,45–11,64%) aumentaram com os níveis crescente de proteína na dieta. A mesma análise foi realizada para o lodo do bioflocos, que apresentou aumento crescente de PB e N. A sobrevivência foi superior a 80% e os camarões alimentados com dietas contendo 31,28 à 46,34g 100 g-¹ PB obtiveram aumento no peso final (1,52–2,61 g), produtividade (0,69–1,10 kg m-³), ganho em peso (1,38–2,44 g) e eficiência alimentar (77,28–101,68%), enquanto esses índices decresceram no tratamento 51,74 g 100 g-¹ PB. O conteúdo de proteína bruta entre 44,26 à 47,12 g 100 g-¹ PB proporcionou o melhor desempenho de crescimento durante a fase inicial do cultivo do camarão-branco-do-pacífico L. vannamei em bioflocos.(AU)

Isolation and Identification of a Potential Amylolytic Probiotic Bacterium from the Gut of Jundiá Catfish, Rhamdia quelen

ABSTRACT This study aimed to isolate a potential probiotic amylolytic strain from the gut of jundiá catfish to improve carbohydrate digestibility in fish. Two of 31 strains isolated from the foregut of Rhamdia quelen were able to grow on starch-agar medium and were considered amylolytic. The strain that presented higher amylolytic potential, based on a qualitative amylase assay, was chosen. The strain was phenotypically characterized and analysed to determine bile and pH tolerance and extracellular quantitative amylase activity. The probiotic candidate, identified as Aeromonas veronii, showed the ability to survive stresses from a range of pH and bile salt conditions and secreted an interesting enzymatic profile, which may exhibit a synergistic effect when combined with the enzymes secreted by the jundiá catfish, improving carbohydrate digestion in the host. The results demonstrated the potential of A. veronii to improve the digestion process in jundiá by providing exogenous enzymes for the breakdown and absorption of nutrients.

Acid silage of tuna viscera: production, composition, quality and digestibility / Silagem ácida de vísceras de atum: produção, composição, qualidade e digestibilidade

Fish waste processed in the form of silage may constitute an alternative to the use of fishmeal (FM). In this study the composition and quality of the acid silage produced from tuna viscera (TV) were characterized and the digestibility of the nutrients of this product was determined for jundia Rhamdia quelen, using ytrium oxide as an inert marker and a completely randomized design. At the end of thirty days, 61.74% of the crude protein of TV was solubilized. Acid silage from TV presented good nutritional composition (high protein, good amino acid profile and essential fatty acids) and good microbiological quality. Crude protein digestibility was similar (88.52%) for TV and FM, but dry matter digestibility was higher (P<0.05) for (TV) (92.20%). Tuna silage presented as a high nutritional quality and nutrient digestibility for jundiá juveniles, R. quelen. Therefore, this novel ingredient has potential as an alternative protein source in aquafeeds.

Resíduos de pescado processados na forma de silagem podem se constituir em uma alternativa ao uso de farinha de peixe (FM). Neste estudo caracterizou-se a composição e qualidade da silagem ácida produzida a partir de vísceras de atum (TV) e determinou-se a digestibilidade dos nutrientes deste produto para jundiá Rhamdia quelen, utilizando-se o óxido de ítrio como marcador inerte em delineamento completamente casualizado. Ao final de trinta dias, 61. 74% da proteína bruta da TV estava solubilizada. A silagem ácida de TV apresentou boa composição nutricional (alta proteína, bom perfil de aminoácidos e de ácidos graxos essenciais) e qualidade microbiológica satisfatória. A digestibilidade da proteína bruta foi similar (88.52%) para TV e FM, mas a da matéria seca foi maior (P<0.05) para a TV (92.20%). A silagem de atum apresentou-se como um ingrediente proteico de alta qualidade nutritiva e digestiva para juvenis de jundiá, R. quelen. Portanto, este novo ingrediente tem potencial como fonte alternativa de proteína para rações de espécies aquícolas.

Acid silage of tuna viscera: production, composition, quality and digestibility / Silagem ácida de vísceras de atum: produção, composição, qualidade e digestibilidade

Fish waste processed in the form of silage may constitute an alternative to the use of fishmeal (FM). In this study the composition and quality of the acid silage produced from tuna viscera (TV) were characterized and the digestibility of the nutrients of this product was determined for jundia Rhamdia quelen, using ytrium oxide as an inert marker and a completely randomized design. At the end of thirty days, 61.74% of the crude protein of TV was solubilized. Acid silage from TV presented good nutritional composition (high protein, good amino acid profile and essential fatty acids) and good microbiological quality. Crude protein digestibility was similar (88.52%) for TV and FM, but dry matter digestibility was higher (P<0.05) for (TV) (92.20%). Tuna silage presented as a high nutritional quality and nutrient digestibility for jundiá juveniles, R. quelen. Therefore, this novel ingredient has potential as an alternative protein source in aquafeeds.(AU)

Resíduos de pescado processados na forma de silagem podem se constituir em uma alternativa ao uso de farinha de peixe (FM). Neste estudo caracterizou-se a composição e qualidade da silagem ácida produzida a partir de vísceras de atum (TV) e determinou-se a digestibilidade dos nutrientes deste produto para jundiá Rhamdia quelen, utilizando-se o óxido de ítrio como marcador inerte em delineamento completamente casualizado. Ao final de trinta dias, 61. 74% da proteína bruta da TV estava solubilizada. A silagem ácida de TV apresentou boa composição nutricional (alta proteína, bom perfil de aminoácidos e de ácidos graxos essenciais) e qualidade microbiológica satisfatória. A digestibilidade da proteína bruta foi similar (88.52%) para TV e FM, mas a da matéria seca foi maior (P<0.05) para a TV (92.20%). A silagem de atum apresentou-se como um ingrediente proteico de alta qualidade nutritiva e digestiva para juvenis de jundiá, R. quelen. Portanto, este novo ingrediente tem potencial como fonte alternativa de proteína para rações de espécies aquícolas.(AU)

Replacement of animal protein sources by soy protein concentrate for juvenile Nile tilapia / Substituição de fontes de proteína animal pelo concentrado proteico de soja para juvenis de tilápia-do-nilo

Soy protein concentrate (SPC) was evaluated as a dietary replacement of animal protein sources (fish meal and poultry by-product meal) (APS) for juvenile Nile tilapia (Oreochromis niloticus). Apparent digestibility coefficients (ADC) of crude protein (CP) and dry matter (DM) were evaluated by feeding tilapia an experimental diet composed of 69.5% reference diet, 30% SPC, and 0.5% chromic oxide as inert marker. Apparent digestibility coefficients were 96.57% for CP and 76.84% for DM. In a feeding trial, increasing levels of dietary SPC (0, 33, 67, and 100%) replaced APS and were fed to tilapia juveniles (10.0 ± 0.18 g) for 60 days. Daily weight gain, specific growth rate, protein retention, feed conversion, body composition and liver histology were not significantly (P>0.05) affected by protein replacement. A second feeding trial compared tilapias growth performance when SPC was supplemented with methionine and threonine (100% SPC+aa, 100% SPC, and 0% SPC) as well as CP and DM digestibility. The amino acid supplementation of SPC significantly increased tilapia daily weight gain. Diets containing 100%SPC and 100% SPC+aa promoted higher protein ADC values than diet containing only APS. However, DM ADC values were significantly higher in fish fed 0% SPC when compared to 100% SPC. Therefore, SPC canreplace poultry by-product meal and fish meal in diets for Nile tilapia without compromising growth performance, protein retention, body composition, liver histology, and protein digestibility. However, SPC supplementation with limiting amino acids, such as methionine and threonine, is advisable since it further increases weight gain and protein digestibility.

Concentrado proteico de soja (CPS) foi avaliado como substituto dietético das farinhas de peixe e vísceras de aves (FP e FVA) para juvenis de tilápia do Nilo (Oreochromis niloticus). Os coeficientes de digestibilidade aparente (CDA) da proteína bruta (PB) e matéria seca (MS) foram avaliados com o fornecimento de dieta experimental composta de 69,5% da dieta referência, 30% CPS e 0,5% de óxido de cromo como marcador inerte. O CDA foi de 96,57% para PB e 76,84% para MS. Em ensaio de alimentação, dietas com níveis crescentes de CPS (0, 33, 67 e 100%) foram oferecidas para juvenis de tilápia (10,0 ± 0,18 g) por 60 dias. Ganho de peso diário, taxa de crescimento específico, retenção proteica, conversão alimentar, composição corporal e histologia hepática não foram afetados (P>0,05) pela substituição. Um segundo ensaio de alimentação comparou crescimento e digestibilidade quando CPS foi suplementado com metionina e treonina (100% CPS+aa, 100% CPS, e 0% CPS). A suplementação resultou em maior ganho de peso diário dos peixes. As dietas 100% e 100% CPS+aa promoveram maiores CDA para proteína que a dieta 0% CPS. No entanto, o CDA para MS foi significativamente maior nos peixes alimentados com 0% CPS quando comparado com 100% CPS. CPS pode substituir FP e FVA em dietas de tilápia do Nilo sem comprometer o desempenho do crescimento, retenção proteica, composição corporal, histologia hepática e digestibilidade proteica. A suplementação de CPS com aminoácidos limitantes, como metionina e treonina, é aconselhável, pois aumenta o ganho de peso e digestibilidade proteica.

Replacement of animal protein sources by soy protein concentrate for juvenile Nile tilapia / Substituição de fontes de proteína animal pelo concentrado proteico de soja para juvenis de tilápia-do-nilo

Soy protein concentrate (SPC) was evaluated as a dietary replacement of animal protein sources (fish meal and poultry by-product meal) (APS) for juvenile Nile tilapia (Oreochromis niloticus). Apparent digestibility coefficients (ADC) of crude protein (CP) and dry matter (DM) were evaluated by feeding tilapia an experimental diet composed of 69.5% reference diet, 30% SPC, and 0.5% chromic oxide as inert marker. Apparent digestibility coefficients were 96.57% for CP and 76.84% for DM. In a feeding trial, increasing levels of dietary SPC (0, 33, 67, and 100%) replaced APS and were fed to tilapia juveniles (10.0 ± 0.18 g) for 60 days. Daily weight gain, specific growth rate, protein retention, feed conversion, body composition and liver histology were not significantly (P>0.05) affected by protein replacement. A second feeding trial compared tilapias growth performance when SPC was supplemented with methionine and threonine (100% SPC+aa, 100% SPC, and 0% SPC) as well as CP and DM digestibility. The amino acid supplementation of SPC significantly increased tilapia daily weight gain. Diets containing 100%SPC and 100% SPC+aa promoted higher protein ADC values than diet containing only APS. However, DM ADC values were significantly higher in fish fed 0% SPC when compared to 100% SPC. Therefore, SPC canreplace poultry by-product meal and fish meal in diets for Nile tilapia without compromising growth performance, protein retention, body composition, liver histology, and protein digestibility. However, SPC supplementation with limiting amino acids, such as methionine and threonine, is advisable since it further increases weight gain and protein digestibility.(AU)

Concentrado proteico de soja (CPS) foi avaliado como substituto dietético das farinhas de peixe e vísceras de aves (FP e FVA) para juvenis de tilápia do Nilo (Oreochromis niloticus). Os coeficientes de digestibilidade aparente (CDA) da proteína bruta (PB) e matéria seca (MS) foram avaliados com o fornecimento de dieta experimental composta de 69,5% da dieta referência, 30% CPS e 0,5% de óxido de cromo como marcador inerte. O CDA foi de 96,57% para PB e 76,84% para MS. Em ensaio de alimentação, dietas com níveis crescentes de CPS (0, 33, 67 e 100%) foram oferecidas para juvenis de tilápia (10,0 ± 0,18 g) por 60 dias. Ganho de peso diário, taxa de crescimento específico, retenção proteica, conversão alimentar, composição corporal e histologia hepática não foram afetados (P>0,05) pela substituição. Um segundo ensaio de alimentação comparou crescimento e digestibilidade quando CPS foi suplementado com metionina e treonina (100% CPS+aa, 100% CPS, e 0% CPS). A suplementação resultou em maior ganho de peso diário dos peixes. As dietas 100% e 100% CPS+aa promoveram maiores CDA para proteína que a dieta 0% CPS. No entanto, o CDA para MS foi significativamente maior nos peixes alimentados com 0% CPS quando comparado com 100% CPS. CPS pode substituir FP e FVA em dietas de tilápia do Nilo sem comprometer o desempenho do crescimento, retenção proteica, composição corporal, histologia hepática e digestibilidade proteica. A suplementação de CPS com aminoácidos limitantes, como metionina e treonina, é aconselhável, pois aumenta o ganho de peso e digestibilidade proteica.(AU)

Exigência de energia em dietas para juvenis de cachara, Pseudoplatystoma reticulatum / Dietary energy requirement for cachara juveniles, Pseudoplatystoma reticulatum

Cachara, Pseudoplatystoma reticulatum, is a carnivorous freshwater catfish with high commercial value in Brazil, but the lack of knowledge about their nutritional requirements hinders the formulation of diets that allow maximum performance. Since cacharas dietary energy requirement is unknown, we tested increasing levels of gross energy (3696, 4049, 4343, 4828 and 5232 kcal kg-1) with isonitrogenous (49% crude protein) diets for juvenile cachara. Groups of nine juveniles (84.43 13.59 g) were stocked into 15 experimental units and fed the experimental diets for 90 days. A polynomial regression analysis revealed a quadratic effect of increasing the concentration of dietary gross energy on weight gain, daily weight gain, specific growth rate, feed conversion, feed efficiency, feed consumption and apparent net protein retention. On the other hand, body fat increased linearly as dietary gross energy increased, contrary to moisture. The digestibility of protein, dry matter and energy did not vary significantly among diets containing 4049, 4343 and 4828 kcal kg-1 gross energy. Therefore, for a maximum daily weight gain, the estimated energy requirement for juvenile cachara of 84.43 g to 240 g is 3497 kcal kg-1 digestible energy equivalent to a 8.08 kcal g-1 digestible energy:digestible protein ratio.

Cachara, Pseudoplatystoma reticulatum, é um bagre carnívoro de água doce que possui alto valor comercial no Brasil, porém, a falta de informações sobre suas exigências nutricionais dificulta a formulação de dietas que permitam máximo desempenho. Foram avaliadas dietas isonitrogenadas (49% de proteína bruta) com níveis crescentes de energia bruta (3.696, 4.049, 4.343, 4.828 e 5.232 kcal kg-1) para juvenis (84,43 13,59 g) de cachara. Grupos de nove peixes foram estocados em 15 unidades experimentais e alimentados duas vezes ao dia, às 9:00 h e 19:00 h, até a saciedade aparente, com as diferentes dietas experimentais por 90 dias. Pela análise de regressão polinomial foi observado efeito quadrático do aumento da concentração de energia bruta da dieta sobre o ganho em peso, ganho em peso diário, taxa de crescimento específico, conversão alimentar, eficiência alimentar, consumo alimentar e taxa de retenção proteica. A gordura corporal aumentou linearmente com o aumento de energia bruta na dieta, ao contrário da umidade. A digestibilidade da proteína, matéria seca e energia não variaram significativamente entre as dietas contendo 4.049, 4.343 e 4.828 kcal kg-1 de energia bruta. Portanto, para um máximo ganho em peso diário, a exigência energética estimada para juvenis de cachara com peso entre 84,43 g e 240 g é de 3.497 kcal kg-1 de energia digestível e equivale a uma relação energia digestível:proteínadigestível de 8,08 kcal g-1.

Exigência de energia em dietas para juvenis de cachara, Pseudoplatystoma reticulatum / Dietary energy requirement for cachara juveniles, Pseudoplatystoma reticulatum

Cachara, Pseudoplatystoma reticulatum, is a carnivorous freshwater catfish with high commercial value in Brazil, but the lack of knowledge about their nutritional requirements hinders the formulation of diets that allow maximum performance. Since cacharas dietary energy requirement is unknown, we tested increasing levels of gross energy (3696, 4049, 4343, 4828 and 5232 kcal kg-1) with isonitrogenous (49% crude protein) diets for juvenile cachara. Groups of nine juveniles (84.43 13.59 g) were stocked into 15 experimental units and fed the experimental diets for 90 days. A polynomial regression analysis revealed a quadratic effect of increasing the concentration of dietary gross energy on weight gain, daily weight gain, specific growth rate, feed conversion, feed efficiency, feed consumption and apparent net protein retention. On the other hand, body fat increased linearly as dietary gross energy increased, contrary to moisture. The digestibility of protein, dry matter and energy did not vary significantly among diets containing 4049, 4343 and 4828 kcal kg-1 gross energy. Therefore, for a maximum daily weight gain, the estimated energy requirement for juvenile cachara of 84.43 g to 240 g is 3497 kcal kg-1 digestible energy equivalent to a 8.08 kcal g-1 digestible energy:digestible protein ratio.(AU)

Cachara, Pseudoplatystoma reticulatum, é um bagre carnívoro de água doce que possui alto valor comercial no Brasil, porém, a falta de informações sobre suas exigências nutricionais dificulta a formulação de dietas que permitam máximo desempenho. Foram avaliadas dietas isonitrogenadas (49% de proteína bruta) com níveis crescentes de energia bruta (3.696, 4.049, 4.343, 4.828 e 5.232 kcal kg-1) para juvenis (84,43 13,59 g) de cachara. Grupos de nove peixes foram estocados em 15 unidades experimentais e alimentados duas vezes ao dia, às 9:00 h e 19:00 h, até a saciedade aparente, com as diferentes dietas experimentais por 90 dias. Pela análise de regressão polinomial foi observado efeito quadrático do aumento da concentração de energia bruta da dieta sobre o ganho em peso, ganho em peso diário, taxa de crescimento específico, conversão alimentar, eficiência alimentar, consumo alimentar e taxa de retenção proteica. A gordura corporal aumentou linearmente com o aumento de energia bruta na dieta, ao contrário da umidade. A digestibilidade da proteína, matéria seca e energia não variaram significativamente entre as dietas contendo 4.049, 4.343 e 4.828 kcal kg-1 de energia bruta. Portanto, para um máximo ganho em peso diário, a exigência energética estimada para juvenis de cachara com peso entre 84,43 g e 240 g é de 3.497 kcal kg-1 de energia digestível e equivale a uma relação energia digestível:proteínadigestível de 8,08 kcal g-1.(AU)

Characterization of the ovary fatty acids composition of Rhamdia quelen (Quoy & Gaimard) (Teleostei: Siluriformes), throughout their reproductive cycle

Knowledge about gonad fatty acid composition is important for broodstock diet formulation. This study characterized ovary fatty acid composition of wild female jundiá catfish (Rhamdia quelen) in their different gonadal maturation stages. Female jundiá (n = 36, average weight= 383.8 + 208.8 g) were captured in the rio Uruguay, comprising all seasons. Ovaries were extracted and classified according to their gonadal maturation stage. Gonad-somatic ratio varied significantly among seasons, being higher in spring (3.7), followed by summer (2.2), winter (0.9) and autumn (0.6). Main fatty acids groups detected were: saturated (SFA= 35.5%), monounsaturated (MUFA= 28.1%) and polyunsaturated fatty acids (PUFA= 33.5%). Over the four seasons, palmitic acid was recorded in large quantities, followed by docosahexaenoic acid (DHA) and arachidonic acid (ARA). ARA was present in higher concentrations in immature or maturing ovaries, and its content decreased along the maturation process. Conversely, DHA and eicosapentaenoic acid (EPA) contents increased during maturation. Such variation resulted in an increase in EPA/ARA and DHA/ARA ratios in mature gonads, which can be important for successful breeding. Such findings suggest that jundiá broodstock diets should contain lipids that provide long chain polyunsaturated fatty acids from both the n-3 and n-6 series to ensure gonadal maturation completion.

O conhecimento da composição de ácidos graxos da gônada, como dos fatores que a influenciam são importantes na formulação de dietas para reprodutores de qualquer espécie. O presente estudo caracteriza a composição de ácidos graxos da gônada de fêmeas de jundiá (Rhamdia quelen) selvagens em seus diferentes estágios de maturação gonadal. Fêmeas de jundiá (n = 36) com peso médio de 383,8 + 208,8 g foram capturadas no alto rio Uruguai, ao longo de um ano, abrangendo as quatro estações. As gônadas foram extraídas, classificadas e posteriormente sua composição de ácidos graxos foi determinada. A relação gônado-somática variou significativamente entre as estações, sendo maior na primavera (3,7), seguida de verão (2,2), inverno (0,9) e no outono (0,6). Os principais grupos de ácidos graxos detectados foram: saturados (35,5 + 3,5%), monoinsaturados (28,1 + 4,3%) e ácidos graxos poli-insaturados (33,5 + 3,0%), com aproximadamente 30% para cada grupo. Ao longo das quatro estações, o ácido palmítico foi registrado em grandes quantidades, seguido do ácido docosahexaenóico (DHA) e ácido araquidônico (ARA). O ácido araquidônico estava presente em concentrações mais elevadas nas gônadas imaturas que nas gônadas maturas, e seu conteúdo diminuído ao longo do processo de maturação. Inversamente, o conteúdo de DHA e ácido eicosapentaenoico (EPA) aumentaram durante o processo de maturação. Tal variação resultou num aumento das relações EPA/ARA e DHA/ARA nas gônadas maturas, fato que pode ser importante para o sucesso da reprodução no jundiá. Tais resultados sugerem que dietas para reprodutores da espécie devem conter fontes de lipídios que proporcionem ácidos graxos de cadeia longa de ambas series (n-3 e n-6) para assegurar uma correta maturação final da gônada.

Characterization of the ovary fatty acids composition of Rhamdia quelen (Quoy & Gaimard) (Teleostei: Siluriformes), throughout their reproductive cycle

Knowledge about gonad fatty acid composition is important for broodstock diet formulation. This study characterized ovary fatty acid composition of wild female jundiá catfish (Rhamdia quelen) in their different gonadal maturation stages. Female jundiá (n = 36, average weight= 383.8 + 208.8 g) were captured in the rio Uruguay, comprising all seasons. Ovaries were extracted and classified according to their gonadal maturation stage. Gonad-somatic ratio varied significantly among seasons, being higher in spring (3.7), followed by summer (2.2), winter (0.9) and autumn (0.6). Main fatty acids groups detected were: saturated (SFA= 35.5%), monounsaturated (MUFA= 28.1%) and polyunsaturated fatty acids (PUFA= 33.5%). Over the four seasons, palmitic acid was recorded in large quantities, followed by docosahexaenoic acid (DHA) and arachidonic acid (ARA). ARA was present in higher concentrations in immature or maturing ovaries, and its content decreased along the maturation process. Conversely, DHA and eicosapentaenoic acid (EPA) contents increased during maturation. Such variation resulted in an increase in EPA/ARA and DHA/ARA ratios in mature gonads, which can be important for successful breeding. Such findings suggest that jundiá broodstock diets should contain lipids that provide long chain polyunsaturated fatty acids from both the n-3 and n-6 series to ensure gonadal maturation completion.(AU)

O conhecimento da composição de ácidos graxos da gônada, como dos fatores que a influenciam são importantes na formulação de dietas para reprodutores de qualquer espécie. O presente estudo caracteriza a composição de ácidos graxos da gônada de fêmeas de jundiá (Rhamdia quelen) selvagens em seus diferentes estágios de maturação gonadal. Fêmeas de jundiá (n = 36) com peso médio de 383,8 + 208,8 g foram capturadas no alto rio Uruguai, ao longo de um ano, abrangendo as quatro estações. As gônadas foram extraídas, classificadas e posteriormente sua composição de ácidos graxos foi determinada. A relação gônado-somática variou significativamente entre as estações, sendo maior na primavera (3,7), seguida de verão (2,2), inverno (0,9) e no outono (0,6). Os principais grupos de ácidos graxos detectados foram: saturados (35,5 + 3,5%), monoinsaturados (28,1 + 4,3%) e ácidos graxos poli-insaturados (33,5 + 3,0%), com aproximadamente 30% para cada grupo. Ao longo das quatro estações, o ácido palmítico foi registrado em grandes quantidades, seguido do ácido docosahexaenóico (DHA) e ácido araquidônico (ARA). O ácido araquidônico estava presente em concentrações mais elevadas nas gônadas imaturas que nas gônadas maturas, e seu conteúdo diminuído ao longo do processo de maturação. Inversamente, o conteúdo de DHA e ácido eicosapentaenoico (EPA) aumentaram durante o processo de maturação. Tal variação resultou num aumento das relações EPA/ARA e DHA/ARA nas gônadas maturas, fato que pode ser importante para o sucesso da reprodução no jundiá. Tais resultados sugerem que dietas para reprodutores da espécie devem conter fontes de lipídios que proporcionem ácidos graxos de cadeia longa de ambas series (n-3 e n-6) para assegurar uma correta maturação final da gônada.(AU)

Crescimento e perfil enzimático do camarão branco do Pacífico alimentado com extrato de Porphyridium cruentum / Growth and enzymatic profile of the Pacific white shrimp fed with Porphyridium cruentum extract

The study was developed to evaluate the influence of diet supplementation of a polysaccharide extract from the microalgae Porphyridium cruentum, on weight gain, digestive enzyme activity, and Litopenaeus vannamei juvenile survival. The polysaccharides crude extract from microalgae P. cruentum was added at different concentrations (0, 0.5, 1, 1.5, and 2.0%) in a commercial diet and provided to juvenile L. vannamei (6.6 ± 0.2 g). The shrimps (n = 2,000) were fed ad libitum for 30 days in circular tanks with 12 m2 of bottom area (100 shrimp tank-1) and environmental variables (temperature, salinity, dissolved oxygen, photoperiod and levels of total ammonia) were controlled. The supplemented diet with 1% crude extract was responsible for the biggest weight gain (7.28 g) in 30 days. The shrimp body muscle centesimal composition and survival were not affected by the polysaccharide extract supplementation. It was observed a shift in the activity of digestive enzymes from the hepatopancreas to the anterior midgut and mid midgut portions in shrimps with diet supplemented with 1% polysaccharide extract, which may have contributed to a better digestive efficiency. The results indicate that dietary supplementation with crude extract of P. cruentum polysaccharides in a range between 1 and 1.5% increases weight gain and enhances the activity of digestive enzymes in L. vannamei juveniles.

O estudo foi desenvolvido para avaliar a influência da suplementação dietética do extrato de polissacarídeo da microalga Porphyridium cruentum no ganho em peso, na atividade das enzimas digestivas e na sobrevivência de juvenis do camarão Litopenaeus vannamei. O extrato bruto de polissacarídeos, extraído da microalga P. cruentum, foi adicionado em diferentes concentrações (0, 0,5, 1, 1,5 e 2,0%) a uma dieta comercial fornecida a juvenis de L. vannamei (6,6 ± 0,2 g). Os camarões (n = 2.000) foram alimentados ad libitum, durante 30 dias, em tanques circulares com 12 m2 de área de fundo (100 camarões tanque-1) e as variáveis ambientais (temperatura, salinidade, oxigênio dissolvido, fotoperíodo e níveis de amônia total) foram controladas. A dieta suplementada com 1% de extrato bruto foi o responsável pelo maior ganho em peso (7,28 g) em 30 dias, porém, a composição centesimal muscular e a sobrevivência não foram afetadas pela suplementação. Entretanto, verificou-se um deslocamento da atividade das enzimas digestivas do hepatopâncreas para as porções anterior e média do intestino médio nas suplementações com até 1% do extrato, o que pode ter contribuido para uma melhor eficiência digestiva. Os resultados indicam que a suplentação da dieta com extrato bruto de polissacarídeos de P. cruentum numa concentração entre 1 e 1,5% aumenta o ganho em massa e melhora a atividade das enzimas digestivas de juvenisde L. vannamei.

Crescimento e perfil enzimático do camarão branco do Pacífico alimentado com extrato de Porphyridium cruentum / Growth and enzymatic profile of the Pacific white shrimp fed with Porphyridium cruentum extract

The study was developed to evaluate the influence of diet supplementation of a polysaccharide extract from the microalgae Porphyridium cruentum, on weight gain, digestive enzyme activity, and Litopenaeus vannamei juvenile survival. The polysaccharides crude extract from microalgae P. cruentum was added at different concentrations (0, 0.5, 1, 1.5, and 2.0%) in a commercial diet and provided to juvenile L. vannamei (6.6 ± 0.2 g). The shrimps (n = 2,000) were fed ad libitum for 30 days in circular tanks with 12 m2 of bottom area (100 shrimp tank-1) and environmental variables (temperature, salinity, dissolved oxygen, photoperiod and levels of total ammonia) were controlled. The supplemented diet with 1% crude extract was responsible for the biggest weight gain (7.28 g) in 30 days. The shrimp body muscle centesimal composition and survival were not affected by the polysaccharide extract supplementation. It was observed a shift in the activity of digestive enzymes from the hepatopancreas to the anterior midgut and mid midgut portions in shrimps with diet supplemented with 1% polysaccharide extract, which may have contributed to a better digestive efficiency. The results indicate that dietary supplementation with crude extract of P. cruentum polysaccharides in a range between 1 and 1.5% increases weight gain and enhances the activity of digestive enzymes in L. vannamei juveniles.(AU)

O estudo foi desenvolvido para avaliar a influência da suplementação dietética do extrato de polissacarídeo da microalga Porphyridium cruentum no ganho em peso, na atividade das enzimas digestivas e na sobrevivência de juvenis do camarão Litopenaeus vannamei. O extrato bruto de polissacarídeos, extraído da microalga P. cruentum, foi adicionado em diferentes concentrações (0, 0,5, 1, 1,5 e 2,0%) a uma dieta comercial fornecida a juvenis de L. vannamei (6,6 ± 0,2 g). Os camarões (n = 2.000) foram alimentados ad libitum, durante 30 dias, em tanques circulares com 12 m2 de área de fundo (100 camarões tanque-1) e as variáveis ambientais (temperatura, salinidade, oxigênio dissolvido, fotoperíodo e níveis de amônia total) foram controladas. A dieta suplementada com 1% de extrato bruto foi o responsável pelo maior ganho em peso (7,28 g) em 30 dias, porém, a composição centesimal muscular e a sobrevivência não foram afetadas pela suplementação. Entretanto, verificou-se um deslocamento da atividade das enzimas digestivas do hepatopâncreas para as porções anterior e média do intestino médio nas suplementações com até 1% do extrato, o que pode ter contribuido para uma melhor eficiência digestiva. Os resultados indicam que a suplentação da dieta com extrato bruto de polissacarídeos de P. cruentum numa concentração entre 1 e 1,5% aumenta o ganho em massa e melhora a atividade das enzimas digestivas de juvenisde L. vannamei.(AU)