Farmed Fish Benefit From Olive Oil in Their Diets

The results of a new study sug­gests that olive oil extract is ben­e­fi­cial to the health of farmed fish and shows promise as an ingre­di­ent in aqua feed.

The study, ​“Olive oil bioac­tive com­pounds increase body weight, and improve gut health and integrity in gilt­head sea bream” was pub­lished in The British Journal of Nutrition.

During the 90-day study, 1,500 farmed sea breams (sparus aurata) were divided among 20 tanks and fed twice daily. Fish oil in aqua feed was replaced with an olive oil bioac­tive extract (OBE) rich in polyphe­nols. Four con­cen­tra­tions of the OBE were tested; 0.08, 0.17, 0.42, and 0.73 per­cent.

Results showed that the fish fed on the 0.17 and 0.42 per­cent OBE con­cen­trates weighed 5 per­cent more that the other fish. The extract also appeared to reduce the size of fatty deposits in the liver, sug­gest­ing that the extract could poten­tially improve the intesti­nal health of fish.

The research also con­cluded that that the addi­tive had the poten­tial to improve the con­di­tion and defen­sive role of the intes­tine by enhanc­ing the mat­u­ra­tion of ente­ro­cytes, reduc­ing oxida­tive stress, improv­ing the integrity of the intesti­nal epithe­lium and enhanc­ing the intesti­nal innate immune func­tion, as gene expres­sion data indi­cated.

The aqua feed indus­try is under pres­sure to find sus­tain­able veg­etable-based alter­na­tives to marine sourced ingre­di­ents, to meet ris­ing demand for cost-effec­tive feed for farmed fish, which now make up around 50 per­cent of all con­sumed fish.

Yannis Papadopoulos from Corfu Sea Farm told Olive Oil Times, ​“The ingre­di­ents of the fish feed can have a great impact on the health and growth of the fish.”

Challenges to pro­duc­ing plant-based aqua food have included find­ing suit­able veg­etable ingre­di­ents for car­niv­o­rous fish, main­tain­ing sat­is­fac­tory lev­els of omega 3 fatty acids in the fish and per­suad­ing fish farm­ers who demand spe­cific lev­els of oil and fish­meal.

The olive oil-fed sea bream became the lat­est addi­tion to a grow­ing list of farm ani­mals shown to ben­e­fit from a diet that includes olive byprod­ucts. Olive-fed cows on the Japanese island of Shodoshima are health­ier than coun­ter­parts and their Sanuki Wagyu Beef has been hailed for its supe­rior taste and tex­ture.

Earlier this year, Euronews reported on piglets in Belgium fed a mix of olive oil waste, soya and cere­als. The piglets were observed by sci­en­tists to deter­mine if the mix boosted the ani­mals’ health and pro­duc­tiv­ity.

The sci­en­tists focused on deter­min­ing the most ben­e­fi­cial com­po­nents in promis­ing under-val­ued food waste that would be the most ben­e­fi­cial to the ani­mals, build­ing a cat­a­logue of promis­ing waste prod­ucts for feed that could become com­mer­cially avail­able in 2 – 3 years.

• British Journal of Nutrition


• Medical News Bulletin


• Euronews