Towards Sustainable Aquafeeds: Complete Substitution of Fish Oil with Marine Microalga Schizochytrium sp. Improves Growth and Fatty Acid Deposition in Juvenile Nile Tilapia (Oreochromis niloticus).
We conducted a 84-day nutritional feeding experiment with dried whole cells of DHA-rich marine microalga Schizochytrium sp. (Sc) to determine the optimum level of fish-oil substitution (partial or complete) for maximum growth of Nile tilapia. When we fully replaced fish oil with Schizochytrium (Sc100 diet), we found significantly higher weight gain and protein efficiency ratio (PER), and lower (improved) feed conversion ratio (FCR) and feed intake compared to a control diet containing fish oil (Sc0); and no significant change in SGR and survival rate among all diets. The Sc100 diet had the highest contents of 22:6n3 DHA, led to the highest DHA content in fillets, and consequently led to the highest DHA:EPA ratios in tilapia fillets. Schizochytrium sp. is a high quality candidate for complete substitution of fish oil in juvenile Nile tilapia feeds, providing an innovative means to formulate and optimize the composition of tilapia juvenile feed while simultaneously raising feed efficiency of tilapia aquaculture and to further develop environmentally and socially sustainable aquafeeds. Results show that replacing fish oil with DHA-rich marine Sc improves the deposition of n3 LC PUFA levels in tilapia fillet. These results support further studies to lower Schizochytrium production costs and to combine different marine microalgae to replace fish oil and fishmeal into aquafeeds.
Environmental Studies Program, Dartmouth College, Hanover, NH 03755, United States of America.
Pallab K
PK
Sarker
Environmental Studies Program, Dartmouth College, Hanover, NH 03755, United States of America.
Anne R
AR
Kapuscinski
Environmental Studies Program, Dartmouth College, Hanover, NH 03755, United States of America.
Alison J
AJ
Lanois
Environmental Studies Program, Dartmouth College, Hanover, NH 03755, United States of America.
Erin D
ED
Livesey
Environmental Studies Program, Dartmouth College, Hanover, NH 03755, United States of America.
Katie P
KP
Bernhard
Environmental Studies Program, Dartmouth College, Hanover, NH 03755, United States of America.
Mariah L
ML
Coley
D000821:Animal Feed; D000818:Animals; D017756:Aquaculture / Q000379:methods*; D023681:Cichlids / Q000254:growth & development*; D003247:Conservation of Natural Resources; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage; D005227:Fatty Acids / Q000378:metabolism*; D005395:Fish Oils / Q000008:administration & dosage*; D016014:Linear Models; D058086:Microalgae
D004042:Dietary Fats, Unsaturated; D005227:Fatty Acids; D005395:Fish Oils