Is camelina oil a potential replacement of fish oil in tilapia?
Researchers found that the replacement of fish oil by camelina oil in the tilapia diet reduces the DHA and EPA levels in muscle but maintained an adequate n-3/n-6 ratio for human consumption.
Camelina (Camelina sativa) oil is a potential replacement for fish oil in aquaculture feeds. It is high in α-linolenic acid (ALA) (35%), with an omega-3/omega-6 (n-3/n-6) ratio near 2.
Canadian and Mexican researchers tested its effect on the overall performance of tilapia (Oreochromis niloticus var. GIFT), feed utilization, lipid composition and capacity to synthesize the long-chain fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from ALA. The 8-week trial was performed on juvenile tilapia (28±6 g) in a biofloc system. Four dietary treatments were formulated, two containing either fish oil (TFO) or camelina oil (TCO), and two more where fish oil was replaced by camelina oil at low (Low-CO) and mid (Mid-CO) levels. A commercial diet (COM) was used as a reference diet. Compound-specific stable isotope analysis (CSIA) and stable isotope mixing models were used to calculate the contribution of ALA to EPA and DHA synthesis.
The results showed that replacing fish oil by camelina oil had no effect on growth or total lipids in the muscle. However, the tilapia fed on TCO had significantly more phospholipid in muscle compared to tilapia fed TFO. Also, a higher content of linoleic acid and ALA was revealed. ALA content in muscle followed the ALA content in the diets. By contrast, EPA and DHA decreased significantly as the level of dietary camelina oil increased. Despite the variation in fatty acids, n-3 PUFA and the n-3/n-6 ratio in muscle tissue did not show differences among experimental diets.
SIAR indicated that 28% of DHA, 36% of EPA, and 40% of DPA was synthesized from camelina oil ALA.
Full study is available here.
Photo source: Genome Atlantic.