Effect of digestible protein on intermediate metabolism, hepatic enzyme activities, energy reserves, and growth performance of pacu (Piaractus mesopotamicus) in the finishing growth phase.

This study investigated the effect of different levels of digestible protein (DP) on blood metabolites, hepatic enzyme activity of glycolysis and amino acid metabolism, energy reserves, and the production characteristics of pacu (Piaractus mesopotamicus) during the finishing growth phase. Six semi purified and isoenergetic diets, containing 16.3, 20.1, 23.8, 27.2, 31.5, and 34.8% of balanced DP, provided with essential amino acid balance, were hand-fed to pacu (1100.0 ± 10.3 g, initial weight) three times daily for 7 weeks. The experiment consisted of six treatments, with three randomly arranged replicates (tanks) per treatment. The data obtained from this experiment were analyzed by one-way analysis of variance (ANOVA), and significant differences (p < 0.05) between treatments were determined using Tukey's test. Blood metabolites, except serum ammonia and the hepatic enzymes activities of glycolysis and amino acid metabolism, except hexokinase activity were affected (p < 0.05) by balanced DP. The energy reserve indices, except hepatic total lipid content, were also found associated (p < 0.05) with balanced DP. The test diets significantly (p < 0.05) affected growth performance parameters. Higher dietary proteins led to a greater energy uptake by fish from the protein in feed. Overall, fish fed the intermediate level (23.8%) of balanced DP with digestible energy of 17.95 MJ kg-1 showed better production traits and physio-biochemical health markers. This information could help nutritionists and farmers to develop nutritionally balanced and economically and environmentally sustainable aquafeed for promoting healthy and sustainable production of pacu in intensive culture systems.

Dynamics of Growth and Egg Traits in Three Dietary Balanced Protein Scenarios Applied for Laying Hens.

The objective of this study was to evaluate laying hens from 8 to 102 weeks old, regarding their changes in performance, body composition, and egg components produced in three scenarios of nutrition. Three treatments designed to contain different levels of balanced protein (BP) were randomly assigned to the experimental units, performing ten replicates per treatment with 20 birds each. A standard feed was formulated to meet hen requirements and the ideal ratio between essential amino acids. Then, two experimental feeds were formulated to contain 20% above or below the dietary BP used in the standard feed. The responses evaluated were cumulated feed intake (g), daily feed intake (g/day), body weight (g), body composition (g of protein, fat, and ash), hen-housed egg production (%/hen-housed), egg production (%), egg weight (g), egg mass (g), and egg components (percentages of yolk, albumen, and eggshell). The dietary BP influenced the body composition, egg production, egg weight, and egg mass of white laying hens. The increase in dietary BP was related to an increase in body contents and egg weight, whereas hens consuming the low dietary balanced protein presented a lower body weight, leaner, and produced smaller eggs.

Effect of feed restriction on the maintenance energy requirement of broiler breeders.

OBJECTIVE: This study aimed to evaluate the effect of the ad libitum and restricted feeding regimen on fasting heat production (FHP) and body composition. METHODS: Twelve Hubbard broilers breeders were selected with the same body weight and submitted in two feeding regimes: Restricted (T1) with feed intake of 150 g/bird/d and ad libitum (T2). The birds were randomly distributed on the treatments in two runs with three replications per treatment (per run). The birds were adapted to the feed regimens for ten days. After that, they were allocated in the open-circuit chambers and kept for three days for adaptation. On the last day, oxygen consumption (VO2) and carbon dioxide production (VCO2) were measured by 30 h under fasting. The respiratory quotient (RQ) was calculated as the VCO2/VO2 ratio, and the heat production (HP) was obtained using the Brower equation (1985). The FHP was estimated throughout the plateau of HP 12 hours after the feed deprivation. The body composition was analyzed by dual-energy X-ray absorptiometry scanning at the end of each period. Data were analyzed for one-way analysis of variance using the Minitab software. RESULTS: The daily feed intake was 30 g higher to T2 (p<0.01) than the T1. Also, the birds of the T2 had significatively (p<0.05) more oxygen consumption (+3.1 L/kg0.75/d) and CO2 production (+2.2 L/kg0.75/d). That resulted in a higher FHP 359±14 kJ/kg0.75/d for T2 than T1 296±17.23 kJ/kg0.75/d. In contrast, the RQ was not different between treatments, with an average of 0.77 for the fasting condition. In addition, protein and fat composition were not affected by the treatment, while a tendency (p<0.1) was shown to higher bone mineral content on the T1. CONCLUSION: The birds under ad libitum feeding had a higher maintenance energy requirement but their body composition was not affected compared to restricted feeding.

Alternative procedure for determining lysine maintenance requirement in poultry

The objective with this study was to determine the lysine maintenance requirements (LMR) of male and female broilers as animal models. A total of 252 birds were used for nitrogen balance trials during three periods (I: 6-21, II: 22-37, and III: 38-53 days). Six lysine levels were used (2.76, 5.88, 8.99, 12.1, 15.2, and 18.3 g kg−1) with six replications. A control group also included, totalizing seven treatments for males and females for each assay. The experimental period was 15 days. The response variables included nitrogen intake (NI) and excretion (NEX), and their difference was assumed to be deposited as nitrogen. An exponential regression between NEX and lysine intake (LI) was fitted, and LMR was estimated when LI = 0. The daily values for LMR were 9.29, 33.4, and 40.2 mg BW0.67 kg−1 for males and 9.36, 30.0, and 39.4 mg BW0.67 kg−1 for females. The final value for both sexes were 10.1 (period I), 31.5 (period II), and 39.8 mg BW0.67 kg−1 (period III). Expressed as body protein weight at maturity (BPm), the LMR were 172 and 148 (period I), 216 and 207 (period II), and 189 and 180 mg BPm0.73 kg−1 (period III) for males and females, respectively. The results provided ranges of LMR values recommended in previous studies, validating this procedure. The procedure to estimate the requirements presented here provides new insights into the model of amino acid requirement estimations.(AU)

Eichhornia crassipes biomass as a dietary supplement for Pterophyllum scalare (Schultze, 1823)

Current study evaluates the macrophyte biomass of water hyacinth, Eichhornia crassipes, in diet food to improve the growth and survival of angelfish, Pterophyllum scalare. The liquid (extract) and ground modes are employed. Specific growth rate, weight gain, feed intake and final body weight in basal diet and macrophyte extract biomass diets were similar (p > 0.05). Fish survival was high in all dietary treatments (> 90%), while survival percentage of 100% was reported in ground macrophyte biomass treatment. Ground macrophyte biomass may be included in the diet of P. scalare up to 5%. The inclusion of E. crassipes in the diet of P. scalare proved similar or better results than basal diet. The macrophyte proved to be a food strategy in angelfish diets that may be implemented in the speciess diet at 32% levels of crude protein. The latter, easily found in tropical regions, affects directly the speciess growth and survival rates.(AU)

Eichhornia crassipes biomass as a dietary supplement for Pterophyllum scalare (Schultze, 1823)

Current study evaluates the macrophyte biomass of water hyacinth, Eichhornia crassipes, in diet food to improve the growth and survival of angelfish, Pterophyllum scalare. The liquid (extract) and ground modes are employed. Specific growth rate, weight gain, feed intake and final body weight in basal diet and macrophyte extract biomass diets were similar (p > 0.05). Fish survival was high in all dietary treatments (> 90%), while survival percentage of 100% was reported in ground macrophyte biomass treatment. Ground macrophyte biomass may be included in the diet of P. scalare up to 5%. The inclusion of E. crassipes in the diet of P. scalare proved similar or better results than basal diet. The macrophyte proved to be a food strategy in angelfish diets that may be implemented in the species’s diet at 32% levels of crude protein. The latter, easily found in tropical regions, affects directly the species’s growth and survival rates.

Efficacy of Benzocaine, Eugenol, and Menthol as Anesthetics for Freshwater Angelfish.

For the production and commercialization of ornamental fish species, it is indispensable to collect biometric data that facilitate the selection of animals for trade and genetic improvement of the stock. However, during the handling process, fish receive more stress if proper anesthetics are not used. Thus, application of appropriate anesthetics is an important tool for minimizing stress in animals. The objective of this study was to determine the effective concentrations of benzocaine, eugenol, and menthol for achieving anesthesia in Freshwater Angelfish Pterophyllum scalare and to develop induction and recovery response curves for different concentrations of these anesthetics. In total, 75 fish were exposed to five concentrations of the three anesthetics in a completely randomized design: benzocaine at 60, 85, 110, 135, and 160 mg/L; eugenol at 40, 80, 120, 160, and 200 mg/L; and menthol at 50, 75, 150, 200, and 250 mg/L. Each concentration (5 fish/concentration) consisted of five replicates, with each replicate represented by a single fish. The results indicated that the tested substances met the criteria of anesthetic efficiency. The effective concentrations of benzocaine, eugenol, and menthol for the anesthesia of Freshwater Angelfish were identified as 89.25, 90.6, and 92.1 mg/L, respectively.

Determining the daily digestible protein intake for Nile tilapia at different growth stages / Determinação da ingestão diária de proteína digestível para tilápia-do-Nilo em diferentes fases de crescimento

This study aimed to estimate the utilization efficiency and optimal intake of digestible protein to maximize weight gain and feed conversion in Nile tilapia juveniles at different development stages. Four trials, each lasting 45 days, were performed using sexually inverted Nile tilapia juveniles with an initial average weight of 2.01 g (phase A), 14.26 g (phase B), 59.96 g (phase C), and 149.11 g (phase D). The experimental design was completely randomized with five treatments and four replicates. The levels of digestible protein ranged from 175 to 425 g kg-1 (phase A), 163 to 390 g kg-1 (phase B), 150 to 360 g kg-1 (phase C), and 138 to 330 g kg-1 (phase D). The maximum responses in terms of weight gain were obtained with protein intakes (digestible protein) of 88, 328, 713, and 855 mg fish-1 day-1, respectively, for phases A, B, C, and D. The maximum feed conversion ratio was obtained with protein intakes of 78, 272, 697, and 793 mg fish-1 day-1, respectively, for phases A, B, C, and D. The protein utilization efficiency was 52, 51, 51, and 50% for phases A, B, C, and D, respectively.

Objetivou-se estimar a eficiência de utilização e a ingestão ótima de proteína digestível para maximizar o ganho de peso e a conversão alimentar de juvenis de tilápia do Nilo em diferentes fases de crescimento. Cada um dos quatro ensaios durou 45 dias, utilizando-se juvenis revertidos sexualmente com peso médio inicial de 2,01g (fase A), 14,26 g (fase B), 59,96 g (fase C) e 149,11 g (fase D). O delineamento adotado foi o inteiramente ao acaso, com cinco tratamentos e quatro repetições. Os níveis de proteína digestível variaram de 175 a 425 g kg-1 (fase A), de 163 a 390 g kg-1 (fase B), de 150 a 360 g kg-1 (fase C) e de 138 a 330 g kg-1 (fase D). As máximas respostas para ganho de peso foram estimadas com ingestões de proteína de 88, 328, 713 e 855 mg peixe-1 dia-1 nas fases A, B, C e D, respectivamente. Para maximizar a conversão alimentar estimaram-se ingestões de proteína de 78, 272, 697 e 793 mg peixe-1 dia-1 para as fases A, B, C e D, respectivamente. As eficiências de utilização da proteína encontradas para as fases A, B, C e D, foram 52, 51, 51 e 50%, respectivamente.

Determining the daily digestible protein intake for Nile tilapia at different growth stages / Determinação da ingestão diária de proteína digestível para tilápia-do-Nilo em diferentes fases de crescimento

This study aimed to estimate the utilization efficiency and optimal intake of digestible protein to maximize weight gain and feed conversion in Nile tilapia juveniles at different development stages. Four trials, each lasting 45 days, were performed using sexually inverted Nile tilapia juveniles with an initial average weight of 2.01 g (phase A), 14.26 g (phase B), 59.96 g (phase C), and 149.11 g (phase D). The experimental design was completely randomized with five treatments and four replicates. The levels of digestible protein ranged from 175 to 425 g kg-1 (phase A), 163 to 390 g kg-1 (phase B), 150 to 360 g kg-1 (phase C), and 138 to 330 g kg-1 (phase D). The maximum responses in terms of weight gain were obtained with protein intakes (digestible protein) of 88, 328, 713, and 855 mg fish-1 day-1, respectively, for phases A, B, C, and D. The maximum feed conversion ratio was obtained with protein intakes of 78, 272, 697, and 793 mg fish-1 day-1, respectively, for phases A, B, C, and D. The protein utilization efficiency was 52, 51, 51, and 50% for phases A, B, C, and D, respectively.(AU)

Objetivou-se estimar a eficiência de utilização e a ingestão ótima de proteína digestível para maximizar o ganho de peso e a conversão alimentar de juvenis de tilápia do Nilo em diferentes fases de crescimento. Cada um dos quatro ensaios durou 45 dias, utilizando-se juvenis revertidos sexualmente com peso médio inicial de 2,01g (fase A), 14,26 g (fase B), 59,96 g (fase C) e 149,11 g (fase D). O delineamento adotado foi o inteiramente ao acaso, com cinco tratamentos e quatro repetições. Os níveis de proteína digestível variaram de 175 a 425 g kg-1 (fase A), de 163 a 390 g kg-1 (fase B), de 150 a 360 g kg-1 (fase C) e de 138 a 330 g kg-1 (fase D). As máximas respostas para ganho de peso foram estimadas com ingestões de proteína de 88, 328, 713 e 855 mg peixe-1 dia-1 nas fases A, B, C e D, respectivamente. Para maximizar a conversão alimentar estimaram-se ingestões de proteína de 78, 272, 697 e 793 mg peixe-1 dia-1 para as fases A, B, C e D, respectivamente. As eficiências de utilização da proteína encontradas para as fases A, B, C e D, foram 52, 51, 51 e 50%, respectivamente.(AU)

An overview of the ongoing insights in selenium research and its role in fish nutrition and fish health.

In the present review, the ongoing researches about selenium research in fish nutrition have been comprehensively discussed. Selenium research is getting popularity in fish nutrition as it is required for the normal growth and proper physiological and biochemical functions in fish. Its deficiency or surplus amounts create severe problems in fish. It is available as inorganic form, organic form, and nano form. In fish, most of the previous research is about the selenium requirements for fish by using only one selenium source mainly the inorganic one. Selenium shows maximum biological activity and bioavailability when it is supplied in proper form. However, to differentiate the more bioavailable and less toxic form of selenium, sufficient information is needed about the comparative bioavailability of different selenium forms in different fish species. In fish, important data about the new forms of selenoproteins is still scarce. Therefore, it is necessary to focus on the determination and elucidation of the new selenoproteins in fish through the utilization of recent approaches of molecular biology and proteomics. The adaptation of these new approaches will replace the old fashioned methodologies regarding the selenium research in fish nutrition. Moreover, the use of molecular biology and proteomics-based new approaches in combination with selenium research will help in optimizing the area of fish nutrition and will improve the feed intake, growth performance, and more importantly the flesh quality which has a promising importance in the consumer market.

Larviculture of siamese fighting fish Betta splendens in low-salinity water / Larvicultura do betta em água levemente salinizada

The low-salinity water may improve live food utilization during larviculture, mainly when larvae are fed with salt water organisms. This study aimed to determine the median lethal concentration (LC50) of NaCl in water for larvae of Betta splendens, an important ornamental species, and to evaluate the effect of low-salinity on the larviculture during the first 15 days of exogenous feeding. In the first experiment, 400 larvae were stocked in forty 250 mL aquariums, and exposed to ten saline concentrations. In the second experiment, 360 larvae were distributed in 24 1 L aquariums, in a factorial design 2x3 comprising two increasing prey densities, starting with 50 and 100 Artemia nauplii larva-1, and three concentrations of NaCl (0, 2 and 4 g NaCl L-1). After 24, 48, 72 and 96 h of exposure, the LC50 were 11.7, 10.1, 8.2 and 7.1 g NaCl L-1, respectively. At the end of the experiment 2, larvae reared in salinity of 2 and 4 g NaCl L-1 and fed with the initial prey density of 100 nauplii larvae-1 were bigger and heavier. The use of low-saline water (2 to 4 g NaCl L-1) is a safe protocol for larviculture of Siamese fighting fish as it does not affect the survival and optimizes the use of Artemia nauplii when higher prey densities are used.(AU)

A água levemente salinizada melhora o aproveitamento do alimento vivo durante a larvicultura, principalmente quando as larvas são alimentadas com organismos de água salgada. Este estudo objetivou determinar a concentração letal (CL50) de NaCl na água para larvas de Betta splendens, uma importante espécie ornamental, e avaliar os efeitos de salinidades baixas na larvicultura durante os primeiros 15 dias de alimentação exógena. No primeiro experimento, 400 larvas foram estocadas em 40 aquários (250 mL) e expostas a dez concentrações salinas. No segundo experimento, 360 larvas foram distribuídas em 24 aquários de 1 L (15 larvas aquário-1), em esquema fatorial 2x3 com duas densidades crescentes de presas, começando com 50 e 100 náuplios de Artemia larva-1, e três concentrações salinas (0, 2 e 4 g NaCl L-1). Após 24, 48, 72 e 96 h de exposição, a CL50 foi de 11,7; 10,1; 8,2 e 7,1 g NaCl L-1, respectivamente. No final do experimento 2, as larvas mantidas nas salinidades de 2 e 4 g NaCl L-1 e alimentadas na densidade inicial de 100 náuplios larva-1 apresentaram crescimento superior. O uso da água levemente salinizada (2 a 4 g NaCl L-1) é um protocolo seguro para a larvicultura de B. splendens, não afeta a sobrevivência das larvas e otimiza o uso dos náuplios de Artemia quando densidades elevadas de presas são utilizadas.(AU)

Larviculture of siamese fighting fish Betta splendens in low-salinity water / Larvicultura do betta em água levemente salinizada

The low-salinity water may improve live food utilization during larviculture, mainly when larvae are fed with salt water organisms. This study aimed to determine the median lethal concentration (LC50) of NaCl in water for larvae of Betta splendens, an important ornamental species, and to evaluate the effect of low-salinity on the larviculture during the first 15 days of exogenous feeding. In the first experiment, 400 larvae were stocked in forty 250 mL aquariums, and exposed to ten saline concentrations. In the second experiment, 360 larvae were distributed in 24 1 L aquariums, in a factorial design 2x3 comprising two increasing prey densities, starting with 50 and 100 Artemia nauplii larva-1, and three concentrations of NaCl (0, 2 and 4 g NaCl L-1). After 24, 48, 72 and 96 h of exposure, the LC50 were 11.7, 10.1, 8.2 and 7.1 g NaCl L-1, respectively. At the end of the experiment 2, larvae reared in salinity of 2 and 4 g NaCl L-1 and fed with the initial prey density of 100 nauplii larvae-1 were bigger and heavier. The use of low-saline water (2 to 4 g NaCl L-1) is a safe protocol for larviculture of Siamese fighting fish as it does not affect the survival and optimizes the use of Artemia nauplii when higher prey densities are used.

A água levemente salinizada melhora o aproveitamento do alimento vivo durante a larvicultura, principalmente quando as larvas são alimentadas com organismos de água salgada. Este estudo objetivou determinar a concentração letal (CL50) de NaCl na água para larvas de Betta splendens, uma importante espécie ornamental, e avaliar os efeitos de salinidades baixas na larvicultura durante os primeiros 15 dias de alimentação exógena. No primeiro experimento, 400 larvas foram estocadas em 40 aquários (250 mL) e expostas a dez concentrações salinas. No segundo experimento, 360 larvas foram distribuídas em 24 aquários de 1 L (15 larvas aquário-1), em esquema fatorial 2x3 com duas densidades crescentes de presas, começando com 50 e 100 náuplios de Artemia larva-1, e três concentrações salinas (0, 2 e 4 g NaCl L-1). Após 24, 48, 72 e 96 h de exposição, a CL50 foi de 11,7; 10,1; 8,2 e 7,1 g NaCl L-1, respectivamente. No final do experimento 2, as larvas mantidas nas salinidades de 2 e 4 g NaCl L-1 e alimentadas na densidade inicial de 100 náuplios larva-1 apresentaram crescimento superior. O uso da água levemente salinizada (2 a 4 g NaCl L-1) é um protocolo seguro para a larvicultura de B. splendens, não afeta a sobrevivência das larvas e otimiza o uso dos náuplios de Artemia quando densidades elevadas de presas são utilizadas.

Determining the daily digestible protein intake for Nile tilapia at different growth stages / Determinação da ingestão diária de proteína digestível para tilápia-do-nilo em diferentes fases de crescimento

This study aimed to estimate the utilization efficiency and optimal intake of digestible protein to maximize weight gain and feed conversion in Nile tilapia juveniles at different development stages. Four trials, each lasting 45 days, were performed using sexually inverted Nile tilapia juveniles with an initial average weight of 2.01 g (phase A), 14.26 g (phase B), 59.96 g (phase C), and 149.11 g (phase D). The experimental design was completely randomized, with five treatments and four replicates. The levels of digestible protein ranged from 175 to 425 g kg-1 (phase A), 163 to 390 g kg-1 (phase B), 150 to 360 g kg-1 (phase C), and 138 to 330 g kg-1 (phase D). The maximum responses in terms of weight gain were obtained with protein intakes (digestible protein) of 88, 328, 713, and 855 mg fish-1 day-1, respectively for phases A, B, C, and D. The maximum feed conversion ratio was obtained with protein intakes of 78, 272, 697, and 793 mg fish-1 day-1, respectively for phases A, B, C, and D. The protein utilization efficiency was 52, 51, 51, and 50% for phases A, B, C, and D respectively.

Objetivou-se estimar a eficiência de utilização e a ingestão ótima de proteína digestível para maximizar o ganho de peso e a conversão alimentar de juvenis de tilápia-do-nilo em diferentes fases de crescimento. Cada um dos quatro ensaios durou 45 dias, utilizando-se juvenis revertidos sexualmente com peso médio inicial de 2,01g (fase A); 14,26 g (fase B); 59,96 g (fase C) e 149,11 g (fase D). O delineamento adotado foi o inteiramente ao acaso, com cinco tratamentos e quatro repetições. Os níveis de proteína digestível variaram de 175 a 425 g kg-1 (fase A), de 163 a 390 g kg-1 (fase B), de 150 a 360 g kg-1 (fase C) e de 138 a 330 g kg-1 (fase D). As máximas respostas para ganho de peso foram estimadas com ingestões de proteína de 88, 328, 713 e 855 mg peixe-1 dia-1 nas fases A, B, C e D respectivamente. Para maximizar a conversão alimentar estimaram-se ingestões de proteína de 78, 272, 697 e 793 mg peixe-1 dia-1 para as fases A, B, C e D respectivamente. As eficiências de utilização da proteína encontradas para as fases A, B, C e D foram 52, 51, 51 e 50% respectivamente.

Determining the daily digestible protein intake for Nile tilapia at different growth stages / Determinação da ingestão diária de proteína digestível para tilápia-do-nilo em diferentes fases de crescimento

This study aimed to estimate the utilization efficiency and optimal intake of digestible protein to maximize weight gain and feed conversion in Nile tilapia juveniles at different development stages. Four trials, each lasting 45 days, were performed using sexually inverted Nile tilapia juveniles with an initial average weight of 2.01 g (phase A), 14.26 g (phase B), 59.96 g (phase C), and 149.11 g (phase D). The experimental design was completely randomized, with five treatments and four replicates. The levels of digestible protein ranged from 175 to 425 g kg-1 (phase A), 163 to 390 g kg-1 (phase B), 150 to 360 g kg-1 (phase C), and 138 to 330 g kg-1 (phase D). The maximum responses in terms of weight gain were obtained with protein intakes (digestible protein) of 88, 328, 713, and 855 mg fish-1 day-1, respectively for phases A, B, C, and D. The maximum feed conversion ratio was obtained with protein intakes of 78, 272, 697, and 793 mg fish-1 day-1, respectively for phases A, B, C, and D. The protein utilization efficiency was 52, 51, 51, and 50% for phases A, B, C, and D respectively.

Objetivou-se estimar a eficiência de utilização e a ingestão ótima de proteína digestível para maximizar o ganho de peso e a conversão alimentar de juvenis de tilápia-do-nilo em diferentes fases de crescimento. Cada um dos quatro ensaios durou 45 dias, utilizando-se juvenis revertidos sexualmente com peso médio inicial de 2,01g (fase A); 14,26 g (fase B); 59,96 g (fase C) e 149,11 g (fase D). O delineamento adotado foi o inteiramente ao acaso, com cinco tratamentos e quatro repetições. Os níveis de proteína digestível variaram de 175 a 425 g kg-1 (fase A), de 163 a 390 g kg-1 (fase B), de 150 a 360 g kg-1 (fase C) e de 138 a 330 g kg-1 (fase D). As máximas respostas para ganho de peso foram estimadas com ingestões de proteína de 88, 328, 713 e 855 mg peixe-1 dia-1 nas fases A, B, C e D respectivamente. Para maximizar a conversão alimentar estimaram-se ingestões de proteína de 78, 272, 697 e 793 mg peixe-1 dia-1 para as fases A, B, C e D respectivamente. As eficiências de utilização da proteína encontradas para as fases A, B, C e D foram 52, 51, 51 e 50% respectivamente.

Parasitic infections in ornamental cichlid fish in the Peruvian Amazon.

The aim of this study was to evaluate the prevalence and seasonal distribution of the main parasite species in Amazonian ornamental cichlids that affect their trade. The study was conducted from August 2007 to September 2009. We sampled 3042 specimens from 9 different species, of which 9.47% had at least one type of external parasite. 81.25% of the cases occurred in the dry season. Crenicichla anthurus (28.57%) was the most parasitized, followed by Aequidens diadema (26.32%), Pterophyllum scalare (22.69%), Cichlasoma sp. (9.52%), Apistogramma sp. (3.88%) and Symphysodon aequifasciatus (3.66%). Monogenea was the most abundant group of parasites, occurring in 66.67% of the cases, of which 96.88% occurred in the dry season. This parasite infested 95.68% of Pterophyllum scalare, 76.67% of Apistogramma sp, 33.33% of Cichlasoma sp. and 23.81% of Symphysodon aequifasciatus cases. Ichthyophthirius multifiliis infested 100% of Aequidens diadema, 76.19% of Symphysodon aequifasciatus, 66.67% of Cichlasoma sp, 41.67% of Crenicichla anthurus and 23.33% of Apistogramma sp cases. Myxosporidia infested 58.33% of Crenicichla anthurus. Trichodina infested 4.32% of Pterophyllum scalare. The prevalence of these parasites is related to the season, preferred habitat, fish behavior, individual susceptibility and handling of animals during transportation by fishermen.

Parasitic infections in ornamental cichlid fish in the Peruvian Amazon / Infestação parasitária em ciclídeos ornamentais da Amazônia de Peru

The aim of this study was to evaluate the prevalence and seasonal distribution of the main parasite species in Amazonian ornamental cichlids that affect their trade. The study was conducted from August 2007 to September 2009. We sampled 3042 specimens from 9 different species, of which 9.47% had at least one type of external parasite. 81.25% of the cases occurred in the dry season. Crenicichla anthurus (28.57%) was the most parasitized, followed by Aequidens diadema (26.32%), Pterophyllum scalare (22.69%), Cichlasoma sp. (9.52%), Apistogramma sp. (3.88%) and Symphysodon aequifasciatus (3.66%). Monogenea was the most abundant group of parasites, occurring in 66.67% of the cases, of which 96.88% occurred in the dry season. This parasite infested 95.68% of Pterophyllum scalare, 76.67% of Apistogramma sp, 33.33% of Cichlasoma sp. and 23.81% of Symphysodon aequifasciatus cases. Ichthyophthirius multifiliis infested 100% of Aequidens diadema, 76.19% of Symphysodon aequifasciatus, 66.67% of Cichlasoma sp, 41.67% of Crenicichla anthurus and 23.33% of Apistogramma sp cases. Myxosporidia infested 58.33% of Crenicichla anthurus. Trichodina infested 4.32% of Pterophyllum scalare. The prevalence of these parasites is related to the season, preferred habitat, fish behavior, individual susceptibility and handling of animals during transportation by fishermen.(AU)

O objetivo deste estudo foi avaliar a prevalência e distribuição sazonal das principais espécies de parasitas em ciclídeos ornamentais amazônicos que afetam seu comércio. O estudo foi realizado entre agosto de 2007 e setembro de 2009. Foram amostrados 3042 espécimes de 9 espécies diferentes, das quais 9,47% tinham pelo menos um tipo de parasita externo. Na estação seca, ocorreram 81,25% dos casos. Crenicichla anthurus (28,57%) foi o mais parasitado, seguido por Aequidens diadema (26,32%), Pterophyllum scalare (22,69%), Cichlasoma sp. (9,52%), Apistogramma sp. (3,88%), e Symphysodon aequifasciatus (3,66%). Monogenea foi o grupo mais abundante de parasitas, ocorrendo em 66,67% dos casos. Na estação seca, ocorreram 96,88% deles. Este parasita infestou 95,68% dos casos em Pterophyllum scalare, 76,67% em Apistogramma sp., 33,33% em Cichlasoma sp. e 23,81% em Symphysodon aequifasciatus. Ichthyophthirius multifiliis infestou 100% dos casos em Aequidens diadema, 76,19% em Symphysodon aequifasciatus, 66,67% em Cichlasoma sp., 41,67% em Crenicichla anthurus e 23,33% em Apistogramma sp.; Myxosporidia infestou 58,33% dos casos em Crenicichla anthurus; Trichodina infestou 4,32% dos casos em Pterophyllum scalare. A prevalência desses parasitas está relacionada com a época do ano, hábitat preferido, comportamento dos peixes, suscetibilidade individual e manejo dos animais durante o transporte pelos pescadores.(AU)

Parasitic infections in ornamental cichlid fish in the Peruvian Amazon / Infestação parasitária em ciclídeos ornamentais da Amazônia de Peru

The aim of this study was to evaluate the prevalence and seasonal distribution of the main parasite species in Amazonian ornamental cichlids that affect their trade. The study was conducted from August 2007 to September 2009. We sampled 3042 specimens from 9 different species, of which 9.47% had at least one type of external parasite. 81.25% of the cases occurred in the dry season. Crenicichla anthurus (28.57%) was the most parasitized, followed by Aequidens diadema (26.32%), Pterophyllum scalare (22.69%), Cichlasoma sp. (9.52%), Apistogramma sp. (3.88%) and Symphysodon aequifasciatus (3.66%). Monogenea was the most abundant group of parasites, occurring in 66.67% of the cases, of which 96.88% occurred in the dry season. This parasite infested 95.68% of Pterophyllum scalare, 76.67% of Apistogramma sp, 33.33% of Cichlasoma sp. and 23.81% of Symphysodon aequifasciatus cases. Ichthyophthirius multifiliis infested 100% of Aequidens diadema, 76.19% of Symphysodon aequifasciatus, 66.67% of Cichlasoma sp, 41.67% of Crenicichla anthurus and 23.33% of Apistogramma sp cases. Myxosporidia infested 58.33% of Crenicichla anthurus. Trichodina infested 4.32% of Pterophyllum scalare. The prevalence of these parasites is related to the season, preferred habitat, fish behavior, individual susceptibility and handling of animals during transportation by fishermen.

O objetivo deste estudo foi avaliar a prevalência e distribuição sazonal das principais espécies de parasitas em ciclídeos ornamentais amazônicos que afetam seu comércio. O estudo foi realizado entre agosto de 2007 e setembro de 2009. Foram amostrados 3042 espécimes de 9 espécies diferentes, das quais 9,47% tinham pelo menos um tipo de parasita externo. Na estação seca, ocorreram 81,25% dos casos. Crenicichla anthurus (28,57%) foi o mais parasitado, seguido por Aequidens diadema (26,32%), Pterophyllum scalare (22,69%), Cichlasoma sp. (9,52%), Apistogramma sp. (3,88%), e Symphysodon aequifasciatus (3,66%). Monogenea foi o grupo mais abundante de parasitas, ocorrendo em 66,67% dos casos. Na estação seca, ocorreram 96,88% deles. Este parasita infestou 95,68% dos casos em Pterophyllum scalare, 76,67% em Apistogramma sp., 33,33% em Cichlasoma sp. e 23,81% em Symphysodon aequifasciatus. Ichthyophthirius multifiliis infestou 100% dos casos em Aequidens diadema, 76,19% em Symphysodon aequifasciatus, 66,67% em Cichlasoma sp., 41,67% em Crenicichla anthurus e 23,33% em Apistogramma sp.; Myxosporidia infestou 58,33% dos casos em Crenicichla anthurus; Trichodina infestou 4,32% dos casos em Pterophyllum scalare. A prevalência desses parasitas está relacionada com a época do ano, hábitat preferido, comportamento dos peixes, suscetibilidade individual e manejo dos animais durante o transporte pelos pescadores.

Induced reproduction and early development histology of Oscar Astronotus ocellatus (Agassiz, 1831).

Oscar (Astronotus ocellatus) is an important fish from the Amazon Basin that has great potential for fish farming, human consumption, sport fishing and fish keeping. This study aimed to evaluate the effect of two hormonal treatments on the induction of artificial reproduction in broodstock and to describe the histological development of embryos and larvae. Broodstocks were selected and induced using two different hormones: (i) extract of carp pituitary (ECP); and (ii) synthetic human chorionic gonadotropin (hCG). Spawnings were transferred to hatcheries, collected at pre-established times, processed and analysed by histology. Astronotus ocellatus did not respond well to induced reproduction. From 16 couples of breeding fish, only five out of the eight females released oocytes after the hormonal action time, three with hCG and two with ECP; just one male responded positively to hCG. Oscar eggs were oval, and semi-adhesive, the yolk contained granules, and egg diameter was approximately 1.65 ± 0.057 to 1.98 ± 0.038 mm. Development from the initial collection (IC) point until the total absorption of the yolk lasted 315 h, at an average temperature of 27.45 ± 2.13°C. Several events marked embryonic and larval development, including the formation of the optic cup, forebrain, otic vesicle and cephalic divisions. The newly hatched larvae had non-pigmented eyes, and a closed mouth and anus, as well as the presence of adhesive glands on the head. Larval development was characterized by formation of the heart, liver, gaseous bladder, gills, pronephros, brain, fins and also the digestive tract. These results provide important information for the rearing and reproduction of A. ocellatus.

Early development of Betta splendens under stereomicroscopy and scanning electron microscopy.

Betta splendens is a very important ornamental species. The current paper describes the embryonic and larval development of B. splendens under stereomicroscopy and scanning electron microscopy. Eggs and larvae from natural spawning were collected at different developmental stages at previously established intervals and analysed. The eggs of B. splendens are yellowish, clear, spherical, demersal, translucent and telolecithal with a large amount of yolk. Between 0-2 h post-initial collection (hpIC), the eggs were at the egg cell, first cleavage and morula stages. The blastula stage was identified at 2-3 hpIC and the early gastrula phase was observed at 3-4 hpIC with 20% epiboly, which was finalized after 13-18 hpIC. When the pre-larvae were ready to hatch, the appearance of somites and the free tail were observed, at 23-25 hpIC. At 29 hpIC, the majority of larvae had already hatched at an average temperature of 28.4 ± 0.2°C. The newly hatched larvae measured 2.47 ± 0.044 mm total length. The mouth opened at 23 h post-hatching (hPH) and the yolk sac was totally absorbed at 73 hPH. After 156 hPH, the heart was pumping blood throughout the entire larval body. The caudal fin, operculum and eyes were well developed at 264 hPH. When metamorphosis was complete at 768 hPH, the larvae became juveniles. The current study presents the first results about early development of B. splendens and provides relevant information for its reproduction, rearing and biology.

A procedure to evaluate the efficiency of utilization of dietary amino acid for poultry / Um procedimento para avaliar a eficiência de utilização do aminoácido dietético para aves

The aim of this study was to develop a procedure based on Gompertz function to determine the efficiency of utilization of amino acid. The procedure was applied to determine the efficiency of utilization of dietary lysine, methionine+cystine and threonine by growing pullets and based on the efficiencies were estimated the requirements for the growth phase of birds. The Gompertz function was fitted to the data of feed intake, body weight, feather-free body protein weight and feather protein weight of four strains of laying hens in the growth phase. The rates of consumption and daily protein deposition (PD) were calculated. The amino acid deposition was obtained by multiplying the PD by the amino acid concentration in feather protein and feather-free body protein. The results showed that the efficiency of utilization of amino acid decreased with maturity and, conversely, there was a proportional increase of the requirement per kg of weight gain. The procedure based on the Gompertz function to determine the efficiency of utilization of amino acid proved to be suitable to evaluate the efficiency of utilization of amino acid and can be a useful tool to diagnose the effectiveness of the nutritional management, aiding in decision-making on the nutritional management.(AU)

O objetivo deste estudo foi desenvolver um procedimento baseado na função Gompertz para determinar a eficiência de utilização do aminoácido. O procedimento foi aplicado para determinar a eficiência de utilização da lisina, metionina+cistina e treonina da dieta de frangas de postura em crescimento, e com base nas eficiências foram estimadas as exigências para fase de crescimento das aves. A função Gompertz foi ajustada aos dados de consumo de ração, peso corporal, peso proteico do corpo depenado e peso de penas de quatro linhagens de aves de postura na fase de crescimento. As taxas de consumo e deposição diária de proteína (DP) foram calculadas. A deposição do aminoácido foi obtida multiplicando a DP pela concentração do aminoácido nas penas e corpo depenado. Os resultados obtidos demonstraram que as eficiências de utilização dos aminoácidos diminuíram com a maturidade e,inversamente, houve um aumento proporcional da exigência por kg de ganho de peso. O procedimento baseado na função Gompertz para determinar a eficiência de utilização do aminoácido mostrou ser adequado para avaliar a eficiência de utilização do aminoácido e pode ser uma ferramenta útil para diagnosticar a eficácia do manejo nutricional auxiliando na tomada de decisões sobre o manejo nutricional.(AU)