Title: Ability of rainbow trout (Oncorhynchus mykiss) to convert and store EPA and DHA when reared on plant oil replacement feeds Authors
Submitted to: Book of Abstracts Aquaculture America
Publication Type: Abstract Only
Publication Acceptance Date: December 11, 2011
Publication Date: February 29, 2012
Citation: Overturf, K.E., Welker, T.L., Towner, R., Barrows, F., Lapatra, S. 2012. Ability of rainbow trout (Oncorhynchus mykiss) to convert and store EPA and DHA when reared on plant oil replacement feeds. Book of Abstracts Aquaculture America. 1262. Interpretive Summary: This study was conducted to evaluate the potential of rainbow trout to produce healthy long chain omega-3 fatty acids from shorter chain precursors and deposit them in their flesh. Several families of rainbow trout were reared on a plant oil-based sustainable diet that supplied the shorter chain precursors and was low in long chain omega-3 fatty acids. There was a wide range in the levels of long chain omega-3 fatty acids in the tissues of the families studied. From this study we determined that increasing the production of long chain omega 3 fatty acids from shorter chain precursors in rainbow trout can be achieved through selective breeding.
Technical Abstract: To determine the potential for improving the conversion and deposition of the important omega-3 fatty acids docosahexaenoic acid (DHA; 22:6n-3) and eicosapentaenoic acid (EPA; 20:5n-3) in fish, forty-three families of rainbow trout were fed a diet low in these components and then evaluated for their ability to convert and store plant oils that did not contain DHA and EPA in their muscle tissue. The range for EPA and DHA detected in the tissues of different families varied between 10 and 22 mg/ml, and 32 and 74 mg/ml respectively. After adjusting for covariates, an averaged heritability of 0.78±0.11 for DHA and 0.61±0.17 for EPA was calculated. Expression analysis of genes related to the elongation and conversion of lipids were also analyzed and significant differences were found in the expression of some genes between groups of families that were delineated as having relative high, medium and low capabilities of depositing EPA and DHA in their muscle tissue after being reared on the mainly soy/flax oil containing diet. However, none of these genes showed a positive correlation with the high conversion/deposition group.