Aquaculture Nutrition 

About: Aquaculture Nutrition is an academic journal published by Wiley-Blackwell. The journal publishes majorly in the area(s): Fish meal & Feed conversion ratio. It has an ISSN identifier of 1353-5773. Over the lifetime, 2420 publications have been published receiving 75941 citations.

Carbohydrates in fish nutrition: effects on growth, glucose metabolism and hepatic enzymes

Abstract: The utilisation of dietary carbohydrates and their effects on fish metabolism are reviewed. Details on how dietary carbohydrates affect growth, feed utilisation and deposition of nutrients are discussed. Variations in plasma glucose concentrations emphasizing results from glucose tolerance tests, and the impact of adaptation diets are interpreted in the context of secondary carbohydrate metabolism. Our focus then shifts to selected aspects of hormonal regulation of carbohydrate metabolism and dietary carbohydrates and their variable effects on glycogen and glucose turnover. We analyse the interaction of carbohydrates with other nutrients, especially protein and protein sparing, and de novo synthesis of lipids, and finish by discussing the correlation of dietary carbohydrates with fish health.

A feed is only as good as its ingredients – a review of ingredient evaluation strategies for aquaculture feeds

Abstract: The evaluation of feed ingredients is crucial to nutritional research and feed development for aquaculture species. In evaluating ingredients for use in aquaculture feeds, there are several important knowledge components that should be understood to enable the judicious use of a particular ingredient in feed formulation. This includes information on (1) ingredient digestibilities, (2) ingredient palatability and (3) nutrient utilization and interference. Diet design, feeding strategy, faecal collection method and method of calculation all have important implications on the determination of the digestible value of nutrients from any ingredient. There are several ways in which palatability of ingredients can be assessed, usually based on variable inclusion levels of the ingredient in question in a reference diet and feeding of those diets under an apparent satietal or selfregulating feeding regimes. However, the design of the diets, the parameters of assessment and the feeding regime can all be subject to variation depending on subtleties of the experimental design. Clearly, issues relating to feed intake are the key performance criteria in palatability assessments, and it is important that such experiments maintain sufficient stringency to allow some self-discrimination of the test feeds by the fish. The ability of fish to use nutrients from the test ingredient, or defining factors that interfere with that process, is perhaps the most complex and variable part of the ingredient evaluation process. It is crucial to discriminate effects on feed intake from effects on utilization of nutrients from ingredients (for growth and other metabolic processes). To allow an increased focus on nutrient utilization by the animals, there are several experimental strategies that can be adopted, which are based on variations in diet design and feeding regime used. Other issues such as ingredient functionality, influence on immune status and effects on organoleptic qualities are also important consideration in determining the value of ingredients in aquaculture feed formulations. A key aspect to note is the need to design all experiments with sufficient experimental capacity to detect significant effects.

Effects of graded levels of standard soybean meal on intestinal structure, mucosal enzyme activities, and pancreatic response in Atlantic salmon (Salmo salar L.)

Abstract: Duplicate tanks of c.280 g Atlantic salmon (Salmo salar L.) were fed for 60 days on diets in which fishmeal was substituted with graded levels of extracted soybean meal (SBM) comprising 0%, 10%, 15%, 20%, 25% or 35% of total protein. The effects on feed intake, growth, feed conversion, apparent digestibility and utilization of macronutrients and energy, pathohistological response of the distal intestine (DI), activities of digestive enzymes in the mid and distal intestinal mucosa, and faecal trypsin and plasma insulin concentrations were studied. A negative, dose-dependent effect of SBM was observed on nearly all performance parameters with a notable exception of feed intake. The lowest SBM inclusion level of 10% resulted in moderate pathohistological changes in the DI. Each subsequent increase in SBM level increased the number of fish displaying severe changes. In contrast to the mid-intestine (MI), all enzyme activities in the distal intestinal mucosa decreased dose-dependently with increasing SBM inclusion. Faecal trypsin increased up to an SBM inclusion level of 20% and then levelled off. Plasma insulin increased from 0% to 15% SBM inclusion and then decreased. The results suggest that caution should be exercised in the use of even low levels of extracted SBM in salmon feeds.

Prebiotics in aquaculture: a review

Abstract: A prebiotic is a non-digestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or the activity of one or a limited number of bacteria in the colon. Despite the potential benefits to health and performance as noted in various terrestrial animals, the use of prebiotics in the farming of fish and shellfish has been less investigated. The studies of prebiotics in fish and shellfish have investigated the following parameters: effect on growth, feed conversion, gut microbiota, cell damage/morphology, resistance against pathogenic bacteria and innate immune parameters such as alternative complement activity (ACH50), lysozyme activity, natural haemagglutination activity, respiratory burst, superoxide dismutase activity and phagocytic activity. This review discusses the results from these studies and the methods used. If the use of prebiotics leads to health responses becoming more clearly manifested in fish and shellfish, then prebiotics might have the potential to increase the efficiency and sustainability of aquaculture production. However, large gaps of knowledge exist. To fully conclude on the effects of adding prebiotics in fish diets, more research efforts are needed to provide the aquaculture industry, the scientific community, the regulatory bodies and the general public with the necessary information and tools.

Carbohydrates in fish nutrition: digestion and absorption in postlarval stages

Abstract: This review summarizes information regarding digestion and absorption of carbohydrates in cultivated fish Relevant results of studies of digestive enzymes, eg amylase, chitinase, cellulase and brush border disaccharidases are presented Fish amylases appear to be molecularly closely related and to have characteristics comparable to mammalian amylases Whether chitinases and cellulases are endogenous enzymes of some fish species is still a matter of speculation, although recent molecular evidence, at least for chitinase seems to settle the issue in favour of endogenous sources Feed and intestinal microbes may be the source of polysaccharidases in fish feeding on nutrients-containing non-starch polysaccharides Knowledge regarding monosaccharide transport in fish intestine as interpreted from studies of brush border membrane vesicles, everted sleeves of fish intestinal sections and molecular biology is discussed Glucose transporters of the intestinal brush border show characteristics similar to those found in mammals A tabulatory presentation of experimental details and results reported in the literature regarding starch digestibility is included as a basis for discussion Although numerous investigations on digestion of starch and other carbohydrates in fish have been published, the existing information is highly fragmentary As yet, it is impossible to derive a cohesive picture on the integrated process of carbohydrate hydrolysis and absorption and interaction with diet composition for any of the fish species under cultivation The physiological mechanisms behind the species differences are not known