Development of diets to promote growth and stress resistance in juvenile Atlantic cod (Gadus morhua)

Description

Canadian researchers have already developed initial feed formulations for juvenile and broodstock marine fish, but further research is still needed to optimize growth and health of juvenile marine fish in general, and of Atlantic cod in particular. We propose to further improve these existing feed formulations by testing the impact of different protein contents and arachidonic acid (ARA) supplementations on growth rate of juvenile cod. Fish will be further grown on a selection of these diets and respiratory capacity will be measured to relate differences in growth to metabolic costs and assimilation. Furthermore, tolerance to hypoxia will be measured for cod fed the same diets. In addition to checking for the impact of diet on hypoxia tolerance, this will provide us with precious information to predict how long cod can survive when oxygen is not supplied to a tank, according to number and size of fish and tank volume.

Thus, the objectives of this project will be to:

1. Perform small-scale testing of nine experimental diets on juvenile cod based on three protein contents (40, 50, and 60%) and three ARA supplementations (0.5, 2.25, and 4% of total lipids).
2. Determine the apparent digestibility coefficient of the diets.
3. Measurement of standard metabolic rate (SMR), specific dynamic action (SDA), maximal or active metabolic rate (AMR) in normoxia, mild hypoxia and severe hypoxia for fish fed a selection of diets encompassing the range of growth rates obtained in Activity A. Determine the incipient lethal threshold for dissolved oxygen and verify if it is dependent on diet.
4. Determination of lethal dissolved oxygen threshold (tolerance to hypoxia) using the LC50 method and test of a possible effect of diet on hypoxia tolerance.

Program Name

Aquaculture Collaborative Research and Development Program (ACRDP)

Year(s)

2007 - 2009

Ecoregion(s)

Atlantic: Gulf of Maine, Scotian Shelf

Principal Investigator(s)

Denis Chabot
Email: Denis.Chabot@dfo-mpo.gc.ca