Document Type : Research Paper
Authors
1
PhD student, Fisheries Department, Faculty of Natural Resources, University of Guilan, Sowmeh Sara, Guilan, Iran
2
Professor, Fisheries Department, Faculty of Natural Resources, University of Guilan, Sowmeh Sara, Guilan, Iran
3
Professor, Department of Marine Sciences, The Caspian Sea Basin Research Center, University of Guilan, Rasht, Guilan, Iran
4
Assistant professor, International Sturgeon Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Rasht, Iran
Abstract
The aim of this study was to use chironomide as a food in transition to accustom this fish to dry feed and its effect on growth indices, survival, fatty acid profiles and carcass analysis. In order to do the experiment, first, Persian sturgeon larvae were reared for 11 days from the beginning of active feeding with 4 treatments including: 1 (Artemia + Daphnia), 2 (Artemia only), 3 (Artemia + chironomide) and 4 (chironomide only) and in the second stage for transition to the formulated diet, 300 pieces of Persian sturgeon were reared with 3 replicates over 21 days using chironomide and formulated feed. Final weight, growth rate, and feed efficiency were significantly higher in treatment 4 than the other treatments. Specific growth rate and body weight increase in treatment 4 were higher than the other treatments. Feed conversion ratio in treatment 4 was the lowest . The crude protein in the Artemia-fed treatment was higher than the Artemia + Daphnia-fed treatment. Fat and ash contents in the treatment fed with chironomide was higher than the fish fed with Artemia + Daphnia. Analysis of larvae at the end of the first stage showed the effect of live food on fatty acids profile in different treatments (P < 0.05). However, in the adaptation to dry feed, the results changed and no significant differences were observed among the treatments. This study showed that the use of chironomide in the diet of Persian sturgeon at the start of feeding up to the adaption period can increase the DHA/EPA ratio, conversion of short-chain unsaturated fatty acids to long-chain, resulting in an increase in the ratio of n-6 to n-3, as well as more fat absorption in the body and increases growth indices and survival rate in this stage.
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