Antinutritional factors present in plant-derived alternate fish feed ingredients and their effects in fish

Continued growth and intensi¢cation of aquaculture production depends upon the development of sustainable protein sources to replace ¢sh meal in aquafeeds. This document reviews various plant feedstuis, which currently are or potentially may be incorporated into aquafeeds to support the sustainable production of various ¢sh species in aquaculture. The plant feedstuis considered include oilseeds, legumes and cereal grains, which traditionally have been used as protein or energy concentrates as well as novel products developed through various processing technologies. The nutritional composition of these various feedstuis are considered along with the presence of any bioactive compounds that may positively or negatively aiect the target organism. Lipid composition of these feedstuis is not speci¢cally considered although it is recognized that incorporating lipid supplements in aquafeeds to achieve proper fatty acid pro¢les to meet the metabolic requirements of ¢sh and maximize human health bene¢ts are important aspects. Speci¢c strategies and techniques to optimize the nutritional composition of plant feedstuis and limit potentially adverse eiects of bioactive compounds are also described. Such information will provide a foundation for developing strategic research plans for increasing the use of plant feedstuis in aquaculture to reduce dependence of animal feedstuis and thereby enhance the sustainability of aquaculture.

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Expanding the utilization of sustainable plant products in aquafeeds: a review

The current status and future focus of probiotic and prebiotic applications for salmonids

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.

Prebiotics in aquaculture: a review

http://digital.csic.es/bitstream/10261/44729/1/Taranger%20et%20al_%2c%20GCE.pdf

Control of puberty in farmed fish

Farming of Atlantic salmon (Salmo salar) began in Norway in the late 1960s. During the 1980s and 1990s the production spread, mainly to other northwestern European countries and to Chile. In 1980 annual world production was less than 10,000 t and this increased to 850,000 t whole fish produced in 2000. It is projected to approach 2 million t in 2010. The growth rate of the fish in the farms is continuously improving, due to genetic selection, improved diets and feeding and improved management. The improvement in growth ascribed to genetic selection can be as much as 15–20% per generation if the salmon are from a combined family–phenotype selection programme (Gjedrem, 1983). Recent Canadian results have shown that transgenic salmon, which express growth hormone receptor activity in muscle tissues, have a growth rate 2.6–2.9 times that of the control population, mainly because of increased feed intake (Cook et al., 2000a). Selection or transgenic techniques may also influence the composition of the growth, result in improved feed conversion (Thodesen et al., 1999; Cook et al., 2000a) and change the rate of metabolism (Thodesen et al., 1999; Cook et al., 2000b,c). Economical feed conversions in Norwegian salmon farming have changed from more than 2 kg feed dry matter (DM) kg−1 gain in 1980 to approximately 1.15 kg kg−1 at the end of the 1990s. In salmon the biological feed conversion can vary from less than 0.6 to more than 1.3 kg intake kg−1 gain, and the proportion of protein and energy in diet partitioned into gain can vary from 25 to 60%, depending on the formulation of the diet and the size of the fish. Thus, requirement figures must be based on the requirements of the animal, related to growth, nutrient partitioning and the specific physiological processes in which the nutrient is required. Requirements differ throughout the life cycle. This is especially important in salmon, which undergo physiological changes during smoltification and transfer from a life in fresh water to salt water. In addition to developing the ability to maintain the ion balance in the hyperosmotic salt water, the salmon also

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Atlantic Salmon, Salmo Salar

The effects of dietary supplementation with mannanoligosaccharide, fructooligosaccharide or galactooligosaccharide on the growth and feed utilization of Atlantic salmon (Salmo salar)

Adaptation to soybean meal in diets for rainbow trout, Oncorhynchus mykiss

Feed intake, growth and feed utilization of offspring from wild and selected Atlantic salmon (Salmo salar)

The apparent digestibility of diets containing fish meal, soybean meal or bacterial meal fed to Atlantic salmon (Salmo salar): evaluation of different faecal collection methods

Ståle J. Helland

Papers

Atlantic Salmon, Salmo Salar

The effects of dietary supplementation with mannanoligosaccharide, fructooligosaccharide or galactooligosaccharide on the growth and feed utilization of Atlantic salmon (Salmo salar)

Adaptation to soybean meal in diets for rainbow trout, Oncorhynchus mykiss

Feed intake, growth and feed utilization of offspring from wild and selected Atlantic salmon (Salmo salar)

The apparent digestibility of diets containing fish meal, soybean meal or bacterial meal fed to Atlantic salmon (Salmo salar): evaluation of different faecal collection methods