Esmaeil Kazemi; Naser Agh; Hosein Moradian; Sajjad Nazari
Volume 12, Issue 2 , April 2014, , Pages 92-102
Abstract
HUFA (highly unsaturated fatty acids) content is one of the most important indices for determination of food value in fish larvae feeding. The HUFA has also an important role in fish larvae health, growth and survival. Because of this, enrichment methods for increasing of HUFA content in Artemia nauplii ...
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HUFA (highly unsaturated fatty acids) content is one of the most important indices for determination of food value in fish larvae feeding. The HUFA has also an important role in fish larvae health, growth and survival. Because of this, enrichment methods for increasing of HUFA content in Artemia nauplii was developed. The aim of this study was to determine the impacts of dietary of fish and vegetable oil on Rainbow trout, Oncorhynchs mykiss, body composition. The experiments were carried out in six different treatments with three replicates for 2 weeks. The feeding treatments during the first 10 days included: 1) Commercial diet, 2) A. Urmiana nauplii enriched with fish oil, 3) A. urmiana nauplii enriched with Sunflower oil, 4) A. urmiana nauplii enriched with Canola oil, 5) A. urmiana nauplii enriched with Soybean oil, 6) Newly hatched un-enriched A. urmiana nauplii. The highest concentrations of fatty acids in diet were oleic, palmitotic, linoleic, eicosapentaenoic acid (EPA) and stearic acid, while in larvae tissue of trout in all treatments were oleic, linolenic, linoleic, stearic and docosahexaenoic acid (DHA), respectively. The concentrations of eicosapentaenoic acid [20:5(n-3)] in contrast with docosahexaenoic acid [22:6(n-3)] in the Commercial diet were significantly reduced (P<0.05). The highest concentrations of EPA was observed in nauplii enriched with fish oil in which statistically significant in comparison with the other treatments (P<0.05). The DHA content in newly hatched non-enriched nauplii and nauplii enriched with vegetable oil were zero. The results showed that vegetable oil (Canola, Sunflower and Soybean) in comparison with fish oil give more suitable results and thus, the present study suggests that early life stage of larvae growth can be feed wih nauplii enriched with Canola oil.
Esmaeil Kazemi; Naser Agh
Volume 11, Issue 3 , November 2012, , Pages 42-51
Abstract
Chronic stresses can influence the behavioral and physiological activities of animals and can lead to reduction of resistance against disease and decrease in growth rate and production.Artemianauplii enriched with essential nutrients particularly fatty acids have been used to promote growth, survival ...
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Chronic stresses can influence the behavioral and physiological activities of animals and can lead to reduction of resistance against disease and decrease in growth rate and production.Artemianauplii enriched with essential nutrients particularly fatty acids have been used to promote growth, survival and resistance of different species of aquatic animals to various environmental stresses as well as infectious diseases. In this study we investigated the resistance to environmental stress (temperature, salinity and hypoxi) in larvae of rainbow trout fed Artemianauplii enriched with vegetable oils. The experiment was carried out in 6 triplicate treatments for a period of 10 days. The feeding treatments included: 1) commercial starter feed for trout (Control) 2) Artemianauplii enriched with fish oil, 3) Artemianauplii enriched with sunflower oil, 4) Artemianauplii enriched with canola oil, 5) Artemianauplii enriched with soybean oil and 6) newly hatched nauplli of Artemia. The results showed significant differences in tolerance of fish larvae to high temperature (20 and 25°C), hypoxia stress (5 ppm) and salinity stress (10, 15 and 20 mg.l-1) among different groups. Highest survival to all experimental stresses (except in one case) was observed in larvae fed Artemianauplii enriched with canola oil compared to those fed control diet ( p<0.05), but in most cases not significant with larvae fed Artemianauplii enriched with fish oil.