Enrichment of Artemia nauplii with essential fatty acids and vitamin C: effect on rainbow trout (Oncorhynchus mykiss) larvae performance

The effect of essential fatty acids (EFA) and vitamin C-enriched Artemia nauplii on growth, survival, and resistance to temperature (high) stress in rainbow trout larvae reared in tanks were investigated. The larvae (average weight ۱۲۰.۴۳mg±۱۳.۵) were fed ۶ times daily starting at the onset of exogenous feeding for ۱ week. Triplicate groups of fish were offered one of four treatments (۱) commercial starter food for rainbow trout، (۲) newly hatched Artemia nauplii (unenriched) ،(۳) highly unsaturated fatty acid (HUFA) + vitamin C-enriched Artemia nauplii and (۴) combination of ۱۰ % HUFA+ vitamin C enriched nauplii and commercial starter food. After ۱ week, all groups of fish were switched to the commercial diet for an additional period of ۳ weeks. Statistical analysis of growth after the first week and at the end of the experiment, showed that growth of larvae in various treatments was significantly different (P<۰.۰۵). After ۴ weeks, the larvae in treatment ۳ with the average weight of ۶۵۷.۵۰ ± ۵۷.۹۳ mg had the highest body weight (P<۰.۰۵). The highest percentage of survival (۹۶%) was observed in treatment ۳ (P<۰.۰۵). Proximate compositions of trout larvae after one week feeding with experimental diets showed that the protein in the larvae of treatments ۳ and ۴ was significantly different compared to other treatments (P<۰.۰۵). The best result of resistance to temperature (up to ۲۴ºC) was observed in larvae reared on treatment ۳ with ۹۱.۳۴ ± ۱.۵۲ percent (P<۰.۰۵).

کلیدواژه ها:

Essential fatty acid ، vitamin C ، Oncorhynchus mykiss ، stress resistance ، growth and survival