The application of Global Burden of Animal Diseases methodology to aquatic animal production.

The Global Burden of Animal Diseases (GBADs) programme's key objective â€" to provide a systematic approach to determine the burden of animal disease â€" is as relevant to aquatic as to terrestrial animal production systems. However, to date GBADs methods have mainly been applied to terrestrial animal production systems. The challenges in applying GBADs methods, notably the Animal Health Loss Envelope (AHLE), vary considerably by production system. The authors demonstrate how the AHLE can be calculated for rainbow trout production in England and Wales and acknowledge that its application to other systems (e.g. hatchery production, polyculture and no-feed mollusc production) is more complex. For example, in small scale tropical fish production the impact of suboptimal nutrition on production would need to be addressed. Recirculating aquaculture systems have inherent high levels of biosecurity and disease control, and thus low levels of disease. Removing the capital and running costs associated with biosecurity fundamentally changes the system and invalidates the AHLE calculation. Lack of data from many systems, notably small-scale tropical finfish farming, means that expert opinion will be needed to support the application of GBADs methods. While calculation of the AHLE is the focus of this article, it should be noted that attribution to causes and value chain modelling are needed to generate data on the wider societal impact of aquatic animal diseases (and possible interventions), which governments require to support decision-making about resource allocation.

Les principaux objectifs du programme " Impact mondial des maladies animales " (GBADs) visent à fournir une méthode systématique pour déterminer l'impact des maladies animales et sont pertinents aussi bien pour les systèmes de production d'animaux terrestres que pour les systèmes aquacoles. Néanmoins, à ce jour, les méthodes du GBADs ont surtout été appliquées aux systèmes de production d'animaux terrestres. Les difficultés d'application des méthodes du GBADs, en particulier le calcul de l'enveloppe des pertes sanitaires animales varient considérablement d'un système de production à l'autre. Les auteurs décrivent la méthode appliquée pour calculer l'enveloppe des pertes sanitaires animales dans les élevages de truites arc-en-ciel en Angleterre et au pays de Galles, méthode dont ils reconnaissent que l'application à d'autres systèmes (par exemple la production en écloserie, la polyculture et la production de mollusques sans intrants de fourrage) est plus complexe. Par exemple, dans la production de poissons tropicaux à petite échelle, l'impact d'une nutrition sous-optimale sur la production devrait être pris en compte. Les systèmes de recirculation fermée en aquaculture garantissent intrinsèquement des niveaux élevés de biosécurité et de contrôle sanitaire qui se traduisent par un niveau faible de maladies. La suppression des coûts d'investissement et de fonctionnement associés à la biosécurité modifie fondamentalement le système et invalide le calcul de l'enveloppe des pertes sanitaires animales. Compte tenu de l'absence de données disponibles concernant un grand nombre de systèmes, notamment les petits élevages de poissons tropicaux, il faudra recourir aux avis d'experts pour étayer l'application des méthodes du GBADs. Si l'article aborde essentiellement le calcul de l'enveloppe des pertes sanitaires animales, les auteurs signalent l'importance de rechercher les causes et de modéliser les chaînes de valeur afin de générer des données représentatives de l'impact sociétal au sens large des maladies affectant les animaux aquatiques (ainsi que des interventions envisageables), outils indispensables pour étayer les décisions gouvernementales concernant les ressources à allouer.

El objetivo principal del programa sobre el Impacto Global de las Enfermedades Animales (GBADs), a saber, proporcionar un enfoque sistemático para determinar el impacto de dichas enfermedades, es tan pertinente para los sistemas de producción de animales acuáticos como terrestres. Sin embargo, hasta la fecha, los métodos del GBADs se han aplicado principalmente a los sistemas de producción de animales terrestres. Las dificultades que plantea la aplicación de los métodos del GBADs, en particular la cartera de pérdidas en sanidad animal, varían considerablemente según el sistema de producción. Los autores demuestran cómo puede calcularse la cartera de pérdidas en sanidad animal para la producción de trucha arco iris en Inglaterra y Gales y reconocen que su aplicación en otros sistemas (por ejemplo, la producción en viveros, el policultivo y la producción de moluscos sin insumos alimentarios) es más compleja. Por ejemplo, en la producción de peces tropicales a pequeña escala habría que abordar el impacto de una nutrición subóptima en la producción. Los sistemas de recirculación en acuicultura conllevan altos niveles de bioseguridad y control de enfermedades y, por lo tanto, bajos niveles de enfermedad. Si se eliminan los costos de capital y de explotación asociados a la bioseguridad, el sistema cambia radicalmente e invalida el cálculo de la cartera de pérdidas en sanidad animal. La falta de datos de muchos sistemas, especialmente de la cría de peces tropicales a pequeña escala, implica que se necesitará la opinión de expertos para apoyar la aplicación de los métodos del GBADs. Aunque el presente artículo se centra en el cálculo de la cartera de pérdidas en sanidad animal, cabe señalar que la determinación de las causas y la modelización de la cadena de valor son necesarias para generar datos sobre el impacto social más amplio de las enfermedades de los animales acuáticos (y las posibles intervenciones), que los gobiernos necesitan para respaldar la toma de decisiones sobre la asignación de recursos.

A Collaborating Centre for animal health economics in the Americas.

Countries in the Americas play a vital role in global livestock and aquaculture production. With international trade of livestock and aquaculture products becoming an important source of income for countries, there has been an increased interest in using animal health economics for advocacy and allocation of resources. This article discusses the development of a new Collaborating Centre for the Economics of Animal Health and the applications of the Global Burden of Animal Diseases (GBADs) framework in the Americas region. Incentives for the increased use of economics in animal health decision-making and examples from the Americas region are examined. The article then discusses the newly formed World Organisation for Animal Health Collaborating Centre in the Americas region. Finally, it reviews two ongoing case studies that are implementing the GBADs framework in Peru and the United States of America.

Les pays des Amériques jouent un rôle crucial dans la production mondiale d'animaux d'élevage, qu'il s'agisse d'espèces terrestres ou aquatiques. Le commerce international des produits issus de l'élevage et de l'aquaculture étant désormais une source importante de revenus pour les pays, la possibilité d'utiliser les concepts de l'économie de la santé animale à des fins de plaidoyer et d'allocation des ressources suscite un intérêt croissant. Les auteurs abordent la désignation d'un nouveau Centre collaborateur pour l'économie de la santé animale ainsi que les applications du programme " Impact mondial des maladies animales " (GBADs) dans la région des Amériques. Ils examinent les avantages d'une meilleure prise en compte de l'économie dans les prises de décision en matière de santé animale, illustrés par quelques exemples concrets relevés dans la région. Ils décrivent ensuite la création du nouveau Centre collaborateur de l'Organisation mondiale de la santé animale dans la région des Amériques. Enfin, ils présentent deux études de cas menées actuellement concernant la mise en oeuvre du programme GBADs respectivement au Pérou et aux Etats-Unis d'Amérique.

Los países de las Américas desempeñan un papel fundamental en la producción ganadera y acuícola mundial. Dado que el comercio internacional de productos ganaderos y acuícolas se ha convertido en una importante fuente de ingresos para los países, el interés por utilizar la economía de la sanidad animal en favor de la promoción y la asignación de recursos ha ido en aumento. En este artículo se analiza la creación de un nuevo Centro colaborador para la economía de la sanidad animal y las aplicaciones del marco del impacto global de las enfermedades animales (GBADs) en la región de las Américas. Se examinan los incentivos para un mayor uso de la economía en la toma de decisiones sobre sanidad animal, así como ejemplos de la región. A continuación, en el artículo se presenta el recién creado Centro colaborador de la Organización Mundial de Sanidad Animal en la región de las Américas. Por último, se examinan dos estudios de casos en los que se está poniendo en práctica el marco del GBADs en Perú y los Estados Unidos de América.

The economics of shrimp disease.

Shrimp is not only one of the world's most valuable aquaculture species, but also a species that encounter high economic losses due to diseases. Diseases are sufficiently important to influence global supply and prices for longer periods. Profitability is the driving force behind shrimp farming and high profits associated with the absence of disease largely determines where shrimp production does take place; i.e. prevalence of disease leads to geographic relocation. In this paper, a basic economic model for the impact of the disease on a shrimp farm is provided and a Monte Carlo simulation is provided to illustrate the impact of disease on economic risk. Improved technologies, knowledge, and governance are important elements utilized in the mitigation of diseases in various shrimp producing countries. Economic aspects such as profitability in the absence and presence of diseases and cost of treatment determines the global production of shrimp along with shaping technologies and production systems.

Measuring the potential for sustainable intensification of aquaculture in Bangladesh using life cycle assessment.

Food production is a major driver of global environmental change and the overshoot of planetary sustainability boundaries. Greater affluence in developing nations and human population growth are also increasing demand for all foods, and for animal proteins in particular. Consequently, a growing body of literature calls for the sustainable intensification of food production, broadly defined as "producing more using less". Most assessments of the potential for sustainable intensification rely on only one or two indicators, meaning that ecological trade-offs among impact categories that occur as production intensifies may remain unaccounted for. The present study addresses this limitation using life cycle assessment (LCA) to quantify six local and global environmental consequences of intensifying aquaculture production in Bangladesh. Production data are from a unique survey of 2,678 farms, and results show multidirectional associations between the intensification of aquaculture production and its environmental impacts. Intensification (measured in material and economic output per unit primary area farmed) is positively correlated with acidification, eutrophication, and ecotoxicological impacts in aquatic ecosystems; negatively correlated with freshwater consumption; and indifferent with regard to global warming and land occupation. As production intensifies, the geographical locations of greenhouse gas (GHG) emissions, acidifying emissions, freshwater consumption, and land occupation shift from the immediate vicinity of the farm to more geographically dispersed telecoupled locations across the globe. Simple changes in fish farming technology and management practices that could help make the global transition to more intensive forms of aquaculture be more sustainable are identified.

The genetic correlation between feed conversion ratio and growth rate affects the design of a breeding program for more sustainable fish production.

BACKGROUND: Most fish breeding programs aim at improving growth rate and include feed conversion ratio (FCR) neither in the breeding goal nor in the selection index, although decreasing FCR is known to increase farm profit and decrease environmental impacts. This is because FCR is difficult to measure in fish that live in groups and FCR is assumed to have a favourable (negative) genetic correlation with growth, although the magnitude of this correlation is unknown. We investigated the effect of the genetic correlation between growth and FCR on the economic and environmental responses of a two-trait breeding goal (growth and FCR), compared to a single-trait breeding goal (growth only). Next, we evaluated the weights to assign to growth and FCR in a two-trait breeding goal to maximize sustainability of fish production. METHODS: We used pseudo-best linear unbiased prediction (BLUP) index calculations to simulate a breeding program for sea bass. For the single-trait breeding goal, the trait in the breeding goal and in the index was thermal growth coefficient (TGC) and for the two-trait breeding goal, the traits in the breeding goal were TGC and FCR and the traits in the index were TGC and percentage of fat in the dorsal muscle (an indirect measure of FCR). We simulated responses to selection for genetic and phenotypic correlations between TGC and FCR ranging from 0 to - 0.8. Then, in the two-trait breeding goal, we calculated the economic return and the change in eutrophication when using economic values (EV) or environmental values (ENV). RESULTS: When the genetic correlation between TGC and FCR was lower than - 0.45, we found major differences in economic returns and in eutrophication between single and two-trait breeding programs. At a correlation of - 0.25, the two-trait breeding goal based on EV increased economic return by 25% compared to the single-trait breeding goal, while using ENV decreased eutrophication by 1.34% per ton of fish produced after one generation of selection. CONCLUSIONS: The genetic correlation between TGC and FCR affects the magnitude of economic losses due to omitting FCR in the breeding program. In addition, the genetic correlation affects the importance of choosing EV or ENV to reduce eutrophication and increase profit.

Measuring the impacts of aquatic animal diseases: the role of economic analysis.

Aquaculture is an important industry both economically and socially. The majority of this industry is focused on the production of aquatic animals, which may be substantially adversely affected by disease. Economic analyses may be used to inform decision-makers on the aquatic animal disease control choices that are economically optimal. Examples of such analyses are presented in this paper, ranging from basic cost estimates of disease impact to complex, spatial- temporal, bio-economic models. Regardless of the complexity of the analysis, there is a consistent need to collect and analyse good quality data measuring both the production and health of aquatic animals. This would require a variety of individuals and groups, including farmers, scientists and the government, to collaboratively contribute to this end. Given the necessary data, more sophisticated models may be better used to inform decision-making from the farm to the national level. Finally, economic analyses should not be limited to simple aggregated cost and benefit results but rather should include the social and gender impacts of financial decisions, as well as the potential externalities both within and among the various impacted sectors in order to optimise investment at both the farm and national levels.

Le secteur de l'aquaculture joue un rôle important aux plans tant économique que social. La majorité des filières du secteur sont axées sur la production d'animaux aquatiques, espèces susceptibles à des maladies à l'impact souvent considérable. Les décideurs ont la possibilité de recourir à des analyses économiques afin de sélectionner les stratégies de lutte contre les maladies des animaux aquatiques optimales au plan économique. L'auteur présente quelques exemples de ce type d'analyses, qui vont de l'estimation basique des coûts liés à l'impact d'une maladie à des modèles analytiques complexes, spatiotemporels et bioéconomiques. Indépendamment de la complexité de l'analyse, il est à chaque fois indispensable de collecter et d'analyser des données de bonne qualité concernant la production et la santé des animaux aquatiques. La réussite d'une telle entreprise nécessite la contribution d'un large éventail d'acteurs individuels et collectifs travaillant en collaboration, dont les éleveurs, les chercheurs et les instances gouvernementales. Dès lors que l'on dispose des données nécessaires, des modèles plus sophistiqués pourront être utilisés afin d'étayer les prises de décision depuis les élevages jusqu'au niveau national. Enfin, les analyses économiques ne devraient pas se limiter à de simples résultats agrégés des coûts et des bénéfices mais devraient prendre en compte les impacts sociaux des décisions financières et leurs répercussions sexospécifiques, ainsi que les effets externes potentiels sur et parmi les divers secteurs affectés, dans le but d'optimiser les investissements réalisés aussi bien au niveau des élevages qu'à l'échelle nationale.

La acuicultura es una actividad industrial importante, a la vez económica y socialmente. El grueso del sector está dedicado a la producción de animales acuáticos, en los que pueden hacer estragos las enfermedades. Los análisis económicos pueden ser utilizados por las instancias decisorias para decidir con conocimiento de causa acerca de las líneas de actuación económicamente idóneas para combatir las enfermedades de dichos animales. El autor presenta ejemplos de este tipo de análisis, que van desde estimaciones básicas del costo de las consecuencias de una enfermedad hasta complejos modelos bioeconómicos que integran la dimensión espaciotemporal. Ahora bien, sea cual sea el nivel de complejidad del análisis, siempre es necesario reunir y analizar datos de buena calidad que midan tanto la producción como el estado de salud de los animales acuáticos. Para hacer posible tal objetivo sería menester que diversas personas y colectividades, entre ellas productores, científicos y administraciones públicas, trabajaran de consuno con este fin. Habida cuenta de los datos necesarios, es posible dar un mejor uso a modelos más sofisticados para fundamentar los procesos decisorios a todos los niveles, desde la explotación hasta el ámbito nacional. Los resultados de los análisis económicos, por último, lejos de ofrecer meras sumas de costos y beneficios, deberían también dar cuenta de los efectos sociales o ligados al género de las decisiones de índole económica, así como de eventuales influencias externas que se dejen sentir en los diversos sectores afectados, o que se ejerzan de uno a otro de esos sectores, con el fin de optimizar las inversiones tanto en cada explotación como a escala nacional.

Complete genome sequence and phylogenetic analysis of megalocytivirus RSIV-Ku: A natural recombination infectious spleen and kidney necrosis virus.

Megalocytiviruses are classified into three genotypes, infectious spleen and kidney necrosis virus (ISKNV), red seabream virus (RSIV), and turbo reddish body iridovirus (TRBIV), based on the major capsid protein and ATPase genes. However, only a few complete genome sequences have been obtained. This paper reports the complete genome sequence and phylogenetic analysis of an RSIV-Ku strain megalocytivirus. The genome sequence comprises 111,154 bp, has 132 putative open reading frames, and is homologous mostly to ISKNV, except for the sequence in the region 58981-66830, which is more closely related to that of the RSIV genotype. The results imply that RSIV-Ku is actually a natural recombinant virus.

Cost-benefit analysis of aquaculture breeding programs.

BACKGROUND: Profitability of breeding programs is a key determinant in the adoption of selective breeding, and can be evaluated using cost-benefit analysis. There are many options to design breeding programs, with or without a multiplier tier. Our objectives were to evaluate different breeding program designs for aquaculture and to optimize the number of selection candidates for these programs. METHODS: The baseline was based on an existing breeding program for gilthead seabream, where improvement of the nucleus had priority over improvement of the multiplier tier, which was partly replaced once every 3 years. Alternative breeding programs considered were annual multiplier tier replacement, annual multiplier tier replacement with priority on improvement of the multiplier tier, and a program without a multiplier tier. Cost-benefit analyses were performed to compare breeding programs. The outcomes were used to describe relationships between profitability and the number of selection candidates, length of the time horizon, and production output, and to estimate the optimum numbers of selection candidates. RESULTS: The baseline breeding program was profitable after 5 years and reached a net present value of 2.9 million euro in year 10. All alternative programs were more profitable up to year 17. The program without a multiplier tier was the most profitable one up to year 22, followed by the program with annual multiplier tier replacement and nucleus priority. The optimum number of selection candidates increased with the length of the time horizon and production output. CONCLUSIONS: The baseline breeding program was profitable after 5 years. For a short time horizon, putting priority on improvement of the multiplier tier over the nucleus is more profitable than putting priority on nucleus improvement, and vice versa for a long time horizon. Use of a multiplier tier increases the delay between costs made for selection and resulting benefits. Thus, avoiding the use of a multiplier tier will increase the profitability of the breeding program in the short term. The optimum number of selection candidates increases with the length of the time horizon and production output. Using too many selection candidates relative to the optimum leads to less reduction in profitability than using too few selection candidates.

Crop rotations in the sea: Increasing returns and reducing risk of collapse in sea cucumber fisheries.

Rotational harvesting is one of the oldest management strategies applied to terrestrial and marine natural resources, with crop rotations dating back to the time of the Roman Empire. The efficacy of this strategy for sessile marine species is of considerable interest given that these resources are vital to underpin food security and maintain the social and economic wellbeing of small-scale and commercial fishers globally. We modeled the rotational zone strategy applied to the multispecies sea cucumber fishery in Australia's Great Barrier Reef Marine Park and show a substantial reduction in the risk of localized depletion, higher long-term yields, and improved economic performance. We evaluated the performance of rotation cycles of different length and show an improvement in biological and economic performance with increasing time between harvests up to 6 y. As sea cucumber fisheries throughout the world succumb to overexploitation driven by rising demand, there has been an increasing demand for robust assessments of fishery sustainability and a need to address local depletion concerns. Our results provide motivation for increased use of relatively low-information, low-cost, comanagement rotational harvest approaches in coastal and reef systems globally.

Social and economic aspects of aquatic animal health.

Aquaculture is an increasingly important source of animal protein for a growing global population. Disease is a major constraint to production, with resultant socio-economic impacts for individuals, communities and economies which rely on aquaculture. Aquatic animal health is also strongly influenced by human factors, ranging from international trade regulations to the behaviours of individuals working in aquaculture. This article summarises the human factors associated with aquaculture production using international examples for illustration.

L'aquaculture est une source de protéines animales de plus en plus importante compte tenu des besoins d'une population mondiale toujours plus nombreuse. Les maladies sont un obstacle majeur pour la production du secteur, avec des effets socio-économiques importants pour les individus, les communautés et les économies dépendant de l'aquaculture. La santé des animaux aquatiques subit également l'influence de facteurs anthropiques, depuis les réglementations applicables au commerce international jusqu'au comportement des personnels des fermes aquacoles. Cet article résume les facteurs anthropiques associés à l'aquaculture, à partir d'exemples observés dans divers endroits du monde.

La acuicultura constituye una fuente de proteínas animales de creciente importancia para una población mundial que aumenta sin cesar. Las enfermedades, que son el principal factor limitante que pesa sobre la producción, tienen también efectos socioeconómicos para las personas, comunidades y economías que dependen de la acuicultura. La sanidad de los animales acuáticos se ve igualmente muy influida por una panoplia de factores humanos, que van desde los reglamentos de comercio internacional hasta el proceder del personal de las instalaciones acuícolas. Sirviéndose de ejemplos tomados de diferentes países, los autores resumen los factores humanos que influyen en la producción acuícola.

Yeast derived from lignocellulosic biomass as a sustainable feed resource for use in aquaculture.

The global expansion in aquaculture production implies an emerging need of suitable and sustainable protein sources. Currently, the fish feed industry is dependent on high-quality protein sources of marine and plant origin. Yeast derived from processing of low-value and non-food lignocellulosic biomass is a potential sustainable source of protein in fish diets. Following enzymatic hydrolysis, the hexose and pentose sugars of lignocellulosic substrates and supplementary nutrients can be converted into protein-rich yeast biomass by fermentation. Studies have shown that yeasts such as Saccharomyces cerevisiae, Candida utilis and Kluyveromyces marxianus have favourable amino acid composition and excellent properties as protein sources in diets for fish, including carnivorous species such as Atlantic salmon and rainbow trout. Suitable downstream processing of the biomass to disrupt cell walls is required to secure high nutrient digestibility. A number of studies have shown various immunological and health benefits from feeding fish low levels of yeast and yeast-derived cell wall fractions. This review summarises current literature on the potential of yeast from lignocellulosic biomass as an alternative protein source for the aquaculture industry. It is concluded that further research and development within yeast production can be important to secure the future sustainability and economic viability of intensive aquaculture. © 2016 Society of Chemical Industry.

Helminth parasites of finfish commercial aquaculture in Latin America.

Latin America has tripled production by aquaculture up to 78 million tonnes in the past 20 years. However, one of the problems that aquaculture is facing is the presence of helminth parasites and the diseases caused by them in the region. In this review we have collected all the available information on helminths affecting commercial aquaculture in Latin America and the Caribbean (LAC), emphasizing those causing serious economic losses. Monogeneans are by far the most common and aggressive parasites affecting farmed fish in LAC. They have been recognized as serious pathogens in intensive fish culture because they reach high levels of infection rapidly, and can infect other phylogenetically related fish species. The next most important group comprises the larval stages of digeneans (metacercariae) such as Diplostomum sp. and Centrocestus formosanus, which cause serious damage to farmed fish. Since LAC aquaculture has been based mainly on exotic species (tilapia, salmon, trout and carp), most of their parasites have been brought into the region together with the fish for aquaculture. Recently, one of us (A.I.P.-T.) has suggested that monogeneans, which have generally been considered to be harmless, can produce serious effects on the growth of cultured Nile tilapia. Therefore, the introduction of fish together with their 'harmless' parasites into new sites, regions or countries in LAC should be considered a breakdown of biosecurity in those countries involved. Therefore, the application of quarantine procedures and preventive therapeutic treatments should be considered before allowing these introductions into a country.

It is the economy, stupid! Projecting the fate of fish populations using ecological-economic modeling.

Four marine fish species are among the most important on the world market: cod, salmon, tuna, and sea bass. While the supply of North American and European markets for two of these species - Atlantic salmon and European sea bass - mainly comes from fish farming, Atlantic cod and tunas are mainly caught from wild stocks. We address the question what will be the status of these wild stocks in the midterm future, in the year 2048, to be specific. Whereas the effects of climate change and ecological driving forces on fish stocks have already gained much attention, our prime interest is in studying the effects of changing economic drivers, as well as the impact of variable management effectiveness. Using a process-based ecological-economic multispecies optimization model, we assess the future stock status under different scenarios of change. We simulate (i) technological progress in fishing, (ii) increasing demand for fish, and (iii) increasing supply of farmed fish, as well as the interplay of these driving forces under different scenarios of (limited) fishery management effectiveness. We find that economic change has a substantial effect on fish populations. Increasing aquaculture production can dampen the fishing pressure on wild stocks, but this effect is likely to be overwhelmed by increasing demand and technological progress, both increasing fishing pressure. The only solution to avoid collapse of the majority of stocks is institutional change to improve management effectiveness significantly above the current state. We conclude that full recognition of economic drivers of change will be needed to successfully develop an integrated ecosystem management and to sustain the wild fish stocks until 2048 and beyond.

Dietary fish protein hydrolysates containing bioactive motifs affect serum and adipose tissue fatty acid compositions, serum lipids, postprandial glucose regulation and growth in obese Zucker fa/fa rats.

The world's fisheries and aquaculture industries produce vast amounts of protein-containing by-products that can be enzymatically hydrolysed to smaller peptides and possibly be used as additives to functional foods and nutraceuticals targeted for patients with obesity-related metabolic disorders. To investigate the effects of fish protein hydrolysates on markers of metabolic disorders, obese Zucker fa/fa rats consumed diets with 75 % of protein from casein/whey (CAS) and 25 % from herring (HER) or salmon (SAL) protein hydrolysate from rest raw material, or 100 % protein from CAS for 4 weeks. The fatty acid compositions were similar in the experimental diets, and none of them contained any long-chain n-3 PUFA. Ratios of lysine:arginine and methionine:glycine were lower in HER and SAL diets when compared with CAS, and taurine was detected only in fish protein hydrolysate diets. Motifs with reported hypocholesterolemic or antidiabetic activities were identified in both fish protein hydrolysates. Rats fed HER diet had lower serum HDL-cholesterol and LDL-cholesterol, and higher serum TAG, MUFA and n-3:n-6 PUFA ratio compared with CAS-fed rats. SAL rats gained more weight and had better postprandial glucose regulation compared with CAS rats. Serum lipids and fatty acids were only marginally affected by SAL, but adipose tissue contained less total SFA and more total n-3 PUFA when compared with CAS. To conclude, diets containing hydrolysed rest raw material from herring or salmon proteins may affect growth, lipid metabolism, postprandial glucose regulation and fatty acid composition in serum and adipose tissue in obese Zucker rats.

Defining a breeding objective for Nile tilapia that takes into account the diversity of smallholder production systems.

In general, livestock and fish farming systems in developing countries tend to be highly diverse in terms of agro-ecological conditions and market orientation. There are no studies that have investigated if and how this diversity translates to varying preferences for breeding objective traits. This is particularly important for breeding programmes that are organized on a national level (e.g. government-supported nucleus breeding programmes). The aim of this study was to investigate whether Nile tilapia farmers with diverse production systems and economic constraints have different preferences for breeding objective traits. The second objective was to derive a consensus breeding goal, using weighted goal programming that could be used for a national breeding programme for Nile tilapia. A survey was conducted among 100 smallholder Nile tilapia farmers in Kenya to obtain preference values for traits of economic importance, by using multiple pairwise comparisons. Individual and group preference values were estimated using analytical hierarchy process. Low-income farmers preferred harvest weight, while medium- and high-income farmers preferred growth rate and survival. Grouping farmers according to market objective (fingerling production or fattening) showed that fingerling producers preferred growth rate and survival, while fattening farmers preferred harvest weight, height and thickness. Weighted goal programming was used to obtain consensus preference values, and these were used to derive desired gains for a breeding goal of a national breeding programme that takes into account the diversity of smallholder production systems.

Preparation, characterisation and use for antioxidant oligosaccharides of a cellulase from abalone (Haliotis discus hannai) viscera.

BACKGROUND: In China, abalone (Haliotis discus hannai) production is growing annually. During industrial processing, the viscera, which are abundant of cellulase, are usually discarded or processed into low-value feedstuff. Thus, it is of interest to obtain cellulase from abalone viscera and investigate its application for preparation of functional oligosaccharides. RESULTS: A cellulase was purified from the hepatopancreas of abalone by ammonium sulfate precipitation and two-steps column chromatography. The molecular weight of the cellulase was 45 kDa on SDS-PAGE. Peptide mass fingerprinting analysis yielded 103 amino acid residues, which were identical to cellulases from other species of abalone. Substrate specificity analysis indicated that the cellulase is an endo-1,4-ß-glucanase. Hydrolysis of seaweed Porphyra haitanensis polysaccharides by the enzyme produced oligosaccharides with degree of polymerisation of two to four, whose monosaccharide composition was 58% galactose, 4% glucose and 38% xylose. The oligosaccharides revealed 2,2'-diphenyl-1-picrylhydrazyl free radical as well as hydrogen peroxide scavenging activity. CONCLUSION: It is feasible and meaningful to utilise cellulase from the viscera of abalone for preparation of functional oligosaccharides. © 2015 Society of Chemical Industry.

Physiological and condition-related traits in the gynogenetic-sexual Carassius auratus complex: different investments promoting the coexistence of two reproductive forms?

BACKGROUND: Carassius auratus complex is an extraordinary species complex including the diploid and polyploid forms exhibiting asexual and sexual reproduction modes. The coexistence of both forms in the same habitats is currently reported. The stable coexistence of asexual and sexual forms assumes some disadvantages for asexuals that balance the costs of sex. In our study, we hypothesized and tested the differences in physiological (including heamatological and immunological), growth-related, condition-related, and fitness-related traits between gynogenetic females and sexuals. RESULTS: Our results revealed similar growth performance in gynogenetic females and sexuals measured by body size and weight, or expressed by condition factor. The energy allocation in reproduction measured by the relative size of gonads revealed no difference between gynogenetic and sexual females; in addition, both females in spawning expressed the same estradiol levels in blood plasma. We found a gender specific trade-off between investment in reproduction and immunocompetence (measured by the spleen-somatic index). Higher aerobic performance expressed by the heart index and higher oxygen-carrying capacity were found in sexual males, with increasing values before and during spawning. Our study evidenced significantly lower aerobic performance but higher oxygen-carrying capacity per erythrocyte in gynogenetic females when compared to sexuals. IgM production differed between gynogens and sexuals of C. auratus complex. CONCLUSIONS: Our study indicates that a similar amount of energy is invested by both gynogenetic and sexual females of C. auratus complex in reproductive behaviour. We suggest that lower aerobic performance in gynogens may represent their physiological disadvantage balancing the cost of sexual reproduction. A trade-off between the number of erythrocytes and the oxygen-carrying capacity per erythrocyte in sexual males and gynogenetic females may contribute to the coexistence of gynogenetic and sexual forms. In addition, the differences in specific immunity between gynogens and sexuals may also reduce the evolutionary disadvantage of sexual reproduction. In conclusion, we propose that several mechanisms contribute to the coexistence of the gynogenetic-sexual C. auratus complex.

Economic costs of protistan and metazoan parasites to global mariculture.

Parasites have a major impact on global finfish and shellfish aquaculture, having significant effects on farm production, sustainability and economic viability. Parasite infections and impacts can, according to pathogen and context, be considered to be either unpredictable/sporadic or predictable/regular. Although both types of infection may result in the loss of stock and incur costs associated with the control and management of infection, predictable infections can also lead to costs associated with prophylaxis and related activities. The estimation of the economic cost of a parasite event is frequently complicated by the complex interplay of numerous factors associated with a specific incident, which may range from direct production losses to downstream socio-economic impacts on livelihoods and satellite industries associated with the primary producer. In this study, we examine the world's major marine and brackish water aquaculture production industries and provide estimates of the potential economic costs attributable to a range of key parasite pathogens using 498 specific events for the purposes of illustration and estimation of costs. This study provides a baseline resource for risk assessment and the development of more robust biosecurity practices, which can in turn help mitigate against and/or minimise the potential impacts of parasite-mediated disease in aquaculture.

Vulnerability of coastal livelihoods to shrimp farming: Insights from Mozambique.

Millions of people around the world depend on shrimp aquaculture for their livelihoods. Yet, the phenomenal growth of shrimp farming has often given rise to considerable environmental and social damage. This article examines the impacts of commercial, export-oriented shrimp aquaculture on local livelihood vulnerability by comparing the exposure, sensitivity, and adaptive capacity of shrimp farm employees with non-farm employees in rural Mozambique. Exposure to stressors was similar between the two groups. Shrimp farm employees had higher assets and higher adaptive capacity than non-farm employees. However, because their income is heavily dependent on a single commodity, shrimp farm employees were highly susceptible to the boom crop nature of intensive shrimp farming. The implications for aquaculture policy and vulnerability research are discussed. The article argues that coastal vulnerability is dynamic, variable, and influenced by multiple processes operating at multiple scales.