ARS | Publication request: Growth parameters of rainbow trout at differenct life stages reared on either a fish meal or plant protein based diet.

Submitted to: Book of Abstracts World Aquaculture Society
Publication Type: Abstract Only
Publication Acceptance Date: December 15, 2007
Publication Date: February 9, 2008
Repository URL: http://riley.nal.usda.gov/nal_web/digi/submission.html
Citation: Overturf, K.E., Gaylord, T.G. 2008. Growth parameters of rainbow trout at differenct life stages reared on either a fish meal or plant protein based diet.. Book of Abstracts World Aquaculture Society Feb 9-12 Orlando, Florida.

Technical Abstract: Analysis of growth parameters have been researched in a number of aquaculture species with rainbow trout having received a significant amount of attention. Typically most growth studies have evaluated changes in plasma hormone levels or expression in growth genes in fish at a certain life stage. It has been proposed that regulation of protein accretion by synthesis and/or degradation of muscle proteins is critical for determining growth rates in fish. Earlier we evaluated the expression of a number of muscle specific factors during 9 stages of trout development. In order to understand the role of degradation and synthesis in muscle accretion we evaluated the expression and enzymatic activity of components of the degradation pathways along with other genetic and physical parameters in rainbow trout at time periods correlating with a doubling of their average weight from 5 to 400 grams. From a single family of rainbow trout 200 fish were divided into replicate sample groups and reared on either a fish meal based protein diet or a plant protein formulated diet without fishmeal. Two diets that were equal in energy, protein, and lipid content were utilized in the study to assist in determining what physiological processes are playing significant goals in weight gain and nutrient usage. Muscle, liver, plasma, and fillet samples were taken from each group at every weight doubling. Analysis of gene expression for degradation and metabolic factors was performed in liver and muscle. Enzyme analysis of degradation factors was done for muscle samples. Cortisol and IGF levels were examined from isolated plasma and whole body proximates were obtained from fillet samples.