Strand, Åsa
- Department of Aquaculture, Swedish University of Agricultural Sciences
Abstract
The growth of fish is a complex process which represents the net outcome of a series of behavioral and physiological processes beginning with food intake and terminating in the deposition of animal tissue (Brett & Groves, 1979). In every commercial aquaculture situation, knowledge about actual fish growth rates, feed intake and growth efficiency in different conditions, as well as means for estimating and predicting growth, is essential for the viability of the enterprise. The best way to maximize growth efficiency and improve farm economy might be the use of mathematical models for growth rates and feed requirement. These models could, if used properly, be very useful tools from both a production planning and management point of view, and could aid in comparing the actual state of the farming facility with what could be biological achievable (Iwama & Tautz, 1981; Springborn et al., 1994; Cho & Bureau, 1998; Bureau et al., 2000). However, despite many attempts to develop mathematical expressions for describing fish growth, there exists a large diversity of approaches and concepts. It is common to find growth expressed as centimeters per month, instantaneous growth rates, percentage of change in length or percentage of change in weight, often with no reference to temperatures, feed ration or culture conditions (Iwama & Tautz, 1981). A proper growth model will allow estimations of the fish energy (feed) requirements and of fish growth rates. This information will allow a farmer to solve several growth related problems that arise in routine fish culture. For example predicting the final average weight of the fish after a defined rearing time, estimating the time required to achieve a given market size of the fish when rearing the fish at a defined temperature, or decide which average temperature is needed to produce a certain size of fish in a defined period of time. A good model can also provide information about stock biomass and its daily feed requirement (Iwama & Tautz, 1981; Bureau et al., 2000). The objective of this essay is to summarize available information of bioenergetic and growth models. The basics of bioenergetic models, as well as measurement techniques for different parts of the energy budget, will be presented. Pros and cons with energy budgets will be discussed 3 and an alternative and more simple form of the energy budget will be presented. The essay also covers different growth models and their usefulness in aquaculture. Moreover, factors affecting growth and feed intake will be considered. In the end of the essay, practical examples of the use of growth and energy requirement budgets will be demonstrated
Published in
Rapport / Sveriges lantbruksuniversitet, Vattenbruksinstitutionen
2005, number: 42
Publisher: Vattenbruksinstitutionen, SLU
SLU Authors
UKÄ Subject classification
Fish and Aquacultural Science
Permanent link to this page (URI)
https://res.slu.se/id/publ/5952