Growth optimization through compensatory growth in brook trout

Description

The purpose of this project is to develop a feeding program (frequency and rations) that makes it possible to maintain the physiological conditions associated with accelerated growth following a period of fasting (compensatory growth) and particularly an optimization of food conversion in brook trout in commercial contexts. The use of compensatory growth would make it possible to address two major issues in Quebec aquaculture production, i.e., improving conversion efficacy (reduction of costs related to feeding) and reducing organic and phosphorus discharges to the environment. Whereas other projects focus on feed composition, the recommended approach is to optimize the management of feeding in commercial situations, which may be combined advantageously with the use of feed formulations that will have been developed. In order to characterize physiological changes during the period of fasting and the period of accelerated growth following refeeding, concentrations of plasma growth hormones (T3, T4, Gh) will be measured, and trypsin, chymotrypsin and total non-mitochondrial ATP activity and nucleic acid content will be measured in the digestive organs. Muscle nucleic acid content, muscle protein content and muscle water content will also be evaluated. The growth rate of each group will be measured and the conversion rate calculated. The presence of hypertrophy will be evaluated by weighing the various digestive organs targetted, i.e., pylorus and digestive tube.

Program Name

Aquaculture Collaborative Research and Development Program (ACRDP)

Year(s)

2002 - 2005

Ecoregion(s)

National

Principal Investigator(s)

Charley Cyr
Email: Charley.Cyr@dfo-mpo.gc.ca