RESUMO
The primary aim of this study was to comprehensively evaluate the welfare of Nile tilapia (Oreochromis niloticus) throughout their entire life cycle within aquaculture, spanning from reproduction to slaughter. The methodology was structured to identify welfare indicators closely aligned with the principles of animal freedoms defined by the Farm Animal Council, encompassing environmental, health, nutritional, behavioral, and psychological freedom. Notably, psychological freedom was inherently considered within the behavioral and physical analyses of the animals. To accomplish this, an integrative systematic literature review was conducted to define precise indicators and their corresponding reference values for each stage of tilapia cultivation. These reference values were subsequently categorized using a scoring system that assessed the deviation of each indicator from established ideal (score 1), tolerable (score 2), and critical (score 3) ranges for the welfare of the target species. Subsequently, a laboratory experiment was executed to validate the pre-selected health indicators, specifically tailored for the early life stages of tilapia. This test facilitated an assessment of the applicability of these indicators under operational conditions. Building on the insights gained from this experimentation, partial welfare indices (PWIs) were computed for each assessed freedom, culminating in the derivation of a general welfare index (GWI). Mathematical equations were employed to calculate these indices, offering a quantitative and standardized measure of welfare. This approach equips tilapia farmers and processors with the tools necessary for the continuous monitoring and enhancement of their production systems and stimulate the adoption of more sustainable and ethical practices within the tilapia farming.
RESUMO
Gradually, concern for the welfare of aquatic invertebrates produced on a commercial/industrial scale is crossing the boundaries of science and becoming a demand of other societal actors. The objective of this paper is to propose protocols for assessing the Penaeus vannamei welfare during the stages of reproduction, larval rearing, transport, and growing-out in earthen ponds and to discuss, based on a literature review, the processes and perspectives associated with the development and application of on-farm shrimp welfare protocols. Protocols were developed based on four of the five domains of animal welfare: nutrition, environment, health, and behaviour. The indicators related to the psychology domain were not considered a separate category, and the other proposed indicators indirectly assessed this domain. For each indicator, the corresponding reference values were defined based on literature and field experience, apart from the three possible scores related to animal experience on a continuum from positive (score 1) to very negative (score 3). It is very likely that non-invasive methods for measuring the farmed shrimp welfare, such as those proposed here, will become a standard tool for farms and laboratories and that it will become increasingly challenging to produce shrimp without considering their welfare throughout the production cycle.
RESUMO
A feeding trial was performed to assess dietary protein:lipid ratios for the grow-out phase of the bullfrog (Lithobates catesbeianus). Nine balanced isoenergetic diets were formulated, combining three different protein levels (300, 400, and 500 g kg−1) with three different lipid levels (50, 100, and 200 g kg−1), designated as P300/50L, P300/100L, P300/200L, P400/50L, P400/100L, P400/200L, P500/50L, P500/100L, and P500/200L. Additionally, a commercial fish feed, commonly used in Mexico to feed bullfrogs, was also tested during the experiment. Growth performance, animal performance parameters, carcass composition, and fatty acid profiles in muscle and liver were evaluated. The feeding trial results showed that all the experimental diets enhanced growth, feed conversion ratio, and frog-leg weight compared with the commercial diet. Bullfrogs had higher growth with 400 and 500 g kg−1 of dietary protein regardless of dietary lipid content. It was also notable that with the P500/200L diet, frogs doubled the weight of those fed the commercial diet. DHA, EPA, and total omega-3 fatty acids were double in muscle and two to eight times higher in the liver compared with the commercial diet. In all cases, the final proximal composition of carcass reflected the diet composition. It is suggested that a diet containing 400 g kg−1 of protein and 50 g kg−1 lipids (protein/lipid ratio: 7.4; gross energy: 18.2 MJ kg−1) is adequate for bullfrog performance during the grow-out phase to achieve market size in a shorter period, thus, reducing farming risks and production costs.
Assuntos
Animais , Rana catesbeiana/crescimento & desenvolvimento , Proteínas , Dieta/veterinária , LipídeosRESUMO
Muscle growth is regulated by several factors including the growth differentiation factor 8, known as myostatin, an inhibitor of myocyte differentiation and proliferation. Research on myostatin regulation was already conducted to improve growth rates in farmed animals, including aquatic species. To explore the effects of myostatin inactivation in a commercial marine fish (spotted rose snapper, Lutjanus guttatus) in vivo, we induced post-transcriptional silencing (knockdown) of myostatin-1 (mstn-1) by injecting dsiRNA directly into the muscle of juvenile fish (87 days post-hatch) using a commercial polymer as vehicle. Results show a significant decrease in mstn-1 expression starting at 2 days after injection and for up to 5 days. Knockdown of mstn-1 caused muscle fiber hypertrophy (but not hyperplasia); however, there were no significant changes in weight or length. Although still experimental, this study provides evidence that temporary knockdown of mstn-1 in a commercial marine fish in vivo promotes fiber hypertrophy and therefore could potentially help grow-out programmes in fish aquaculture.
Assuntos
Hipertrofia/genética , Miostatina/genética , Miostatina/metabolismo , Animais , Aquicultura , Peixes/genética , Hiperplasia/genética , Músculo Esquelético/metabolismo , Perciformes/genética , Interferência de RNA/fisiologiaRESUMO
Studies related to nictemeral variation were executed in a fish growing pond, during all the seasons of the year, collecting data for dissolved oxygen; temperature; pH and electrical conductivity at the feeding channel on pond's surface, bottom and at streamlet bed. The results showed that Autumn was the season which had the lowest values of water temperature, the interval points, during Spring time, had superior average values of temperature when compared to the ones that were observed at external points. The lowest and highest index of pH were during Autumn season. The electrical conductivity didn't show significant differences during Autumn season. The samples obtained from the streamlet had very high significant differences with the samples of fish pond inner part, showing that there was an influence on external environment from the effluent which came from the inner part of the fish pond on limnology variables.
Realizou-se o experimento de engorda de peixes em um viveiro escavado em terra, com espelho d'água de 2.250m² e profundidade média de 0,91 m, localizado no município de Apucarana (Lat. S. 23º33'26,7", Long. W. 51º 33' 41,7"), norte do Estado do Paraná, Brasil. Durante o período experimental foram feitos estudos de variações nictemerais, durante as quatro estações climáticas do ano, coletando-se os dados no canal de alimentação (ponto 1), na superfície do viveiro (ponto 2), no fundo do viveiro (ponto 3) e no leito do córrego (ponto 4), com quatro variáveis: Oxigênio dissolvido (mg/L) e ( por cento), temperatura (ºC), pH e condutividade elétrica (µ.S/cm). Coletou-se os dados em intervalos de quatro horas, iniciando-se às 08:00 hs. e concluindo no dia seguinte no mesmo horário. Os resultados obtidos indicaram que o outono foi a estação onde ocorreram os menores valores de temperaturas da água; os pontos internos na primavera apresentaram valores médios de temperatura superiores aos observados nos pontos externos. A amplitude entre as taxas máximas e mínimas de oxigênio dissolvido foi de 10,15 mg/L (concentração de 109 por cento), os quais aconteceram nos períodos entre o outono e verão. Identificou-se um pH mínimo, abaixo dos níveis recomendados para a criação de peixes no nictimeral de inverno em todos os pontos. Os menores índices do pH foram 5,05 no ponto 1 ocorrido no outono, enquanto que nos pontos 2, 3 e 4 ficaram em 5,66, 5,23 e 5,23 respectivamente, e que ocorreram no inverno. O máximo do pH registrado foi de 7,9 no outono. A condutividade elétrica e o pH não apresentaram diferenças significativas, no outono. As amostras obtidas no leito do córrego (ponto 4) apresentaram alta diferença significativa (P<0.05) comparadas as amostras da parte interna do viveiro de engorda, significando que houve influência sobre o ambiente externo através do efluente proveniente da parte interna do viveiro de engorda sobre as variáveis limnológicas.
RESUMO
Realizou-se este experimento no Centro de Tecnologia em Aquicultura da Universidade Federal do Ceará no período de 14 de março a 14 de julho de 2006. O objetivo foi comparar o desenvolvimento de juvenis recentes da Panulirus laevicauda, alimentadas com moluscos (Perna perna e Mytella falcata) e dieta peletizada. Desenvolveram-se três tratamentos (TA P. perna, TB M. falcata e TC dieta peletizada) com quatro repetições, distribuídos em delineamento inteiramente casualizado. A densidade de estocagem foi de um indivíduo por recipiente. A alimentação ofertada foi de 10% da biomassa. Na manutenção do experimento, mediram-se o pH, a temperatura e a salinidade e realizaram-se biometrias mensais. Ampliaram-se os seguintes testes estatísticos: Kolmogorov-Smirnov, teste t de Student, ANOVA e o teste do qui-quadrado. Os parâmetros físico-químicos não diferiram estatisticamente entre si (P > 0,05). As taxas em ganhos, incrementos, números de mudas, frequências de mudas e taxas de sobrevivência não apresentaram diferenças estatísticas entre os tratamentos (P > 0,05). A P. laevicauda tem ótima aceitação de uma dieta peletizada na sua alimentação. Já outras espécies de lagostas não se alimentam de tais dietas.
This experiment was carried out at the Technology Center of Aquaculture, Federal University of Ceara during the period of March 14th, 2006 to July 14th, 2006. The objective of this study was to compare the growth of early juveniles of Panulirus laevicauda, fed on molluscs (Perna perna and Mytella falcata) and pelleted feed. The experiments were delineated and conducted using completely randomized distributions. Three treatments (TA P. perna, TB M. falcata and TC pellet feed) were repeated 4 times. Initial density used was one individual per container. The feed rate was 10 % of the individual biomass. The chemical and physical parameters of the experimental water (pH, temperature and salinity) were measured daily and the juveniles were measured verifying cephalotorax and total length and weighed at each 30 days of culture. For the statistical tests Analysis with Kolmogorov-Smirnov the Student Test (chemical and physical parameters), Analysis of Variance (ANOVA) and test CHI-SQUARE, were used. In this work chemical and physical parameters did not show differences among the treatments (P > 0.05). At the end of the experiment, growth rate, number and frequency of molts per individual, and survival rate did not show statistical differences (P > 0.05). P. laevicauda has a good acceptance of pelleted feed but other species of lobster did not feed of this type of diets.
Assuntos
Animais , Moluscos/classificação , Palinuridae/classificação , Aquicultura/instrumentação , Dieta/métodosRESUMO
Realizou-se este experimento no Centro de Tecnologia em Aquicultura da Universidade Federal do Ceará no período de 14 de março a 14 de julho de 2006. O objetivo foi comparar o desenvolvimento de juvenis recentes da Panulirus laevicauda, alimentadas com moluscos (Perna perna e Mytella falcata) e dieta peletizada. Desenvolveram-se três tratamentos (TA P. perna, TB M. falcata e TC dieta peletizada) com quatro repetições, distribuídos em delineamento inteiramente casualizado. A densidade de estocagem foi de um indivíduo por recipiente. A alimentação ofertada foi de 10% da biomassa. Na manutenção do experimento, mediram-se o pH, a temperatura e a salinidade e realizaram-se biometrias mensais. Ampliaram-se os seguintes testes estatísticos: Kolmogorov-Smirnov, teste t de Student, ANOVA e o teste do qui-quadrado. Os parâmetros físico-químicos não diferiram estatisticamente entre si (P > 0,05). As taxas em ganhos, incrementos, números de mudas, frequências de mudas e taxas de sobrevivência não apresentaram diferenças estatísticas entre os tratamentos (P > 0,05). A P. laevicauda tem ótima aceitação de uma dieta peletizada na sua alimentação. Já outras espécies de lagostas não se alimentam de tais dietas.(AU)
This experiment was carried out at the Technology Center of Aquaculture, Federal University of Ceara during the period of March 14th, 2006 to July 14th, 2006. The objective of this study was to compare the growth of early juveniles of Panulirus laevicauda, fed on molluscs (Perna perna and Mytella falcata) and pelleted feed. The experiments were delineated and conducted using completely randomized distributions. Three treatments (TA P. perna, TB M. falcata and TC pellet feed) were repeated 4 times. Initial density used was one individual per container. The feed rate was 10 % of the individual biomass. The chemical and physical parameters of the experimental water (pH, temperature and salinity) were measured daily and the juveniles were measured verifying cephalotorax and total length and weighed at each 30 days of culture. For the statistical tests Analysis with Kolmogorov-Smirnov the Student Test (chemical and physical parameters), Analysis of Variance (ANOVA) and test CHI-SQUARE, were used. In this work chemical and physical parameters did not show differences among the treatments (P > 0.05). At the end of the experiment, growth rate, number and frequency of molts per individual, and survival rate did not show statistical differences (P > 0.05). P. laevicauda has a good acceptance of pelleted feed but other species of lobster did not feed of this type of diets.(AU)