Shahnour Eshghi; Ahmad Imani; Farzaneh Noori; Naser Agh
Volume 5, Issue 4 , May 2017, , Pages 69-78
Abstract
Main purpose of the present research was to study the effects of replacing green algae with agricultural by-products on growth and survival rate of Artemia franciscana. The study was a 4×2 factorial experiment conducted as a completely randomized design. Factors were different types of diet (wheat ...
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Main purpose of the present research was to study the effects of replacing green algae with agricultural by-products on growth and survival rate of Artemia franciscana. The study was a 4×2 factorial experiment conducted as a completely randomized design. Factors were different types of diet (wheat bran, rice bran, mixture of wheat and rice bran and the alge (Dunaliella salina) and probiotic inclusion level (0 and 10% of the daily meal). All treatments were in triplicates and the experiment lasted for 17 days post hatch. At the end of the trial, growth and the survival rates were calculated. Results showed that total length of Artemia fed wheat bran and alge with probiotic (8.20±0.03 mm) was the highest and that of group fed wheat and rice bran and algae (6.76±0.03 mm) was the lowest (p0.05). According to the results, it seems that unicellular algae can be replaced with easily affordable agricultural by-products and artemia could convert waste to wealth for the sake of environment and expanding aquaculture enterprise.
Abdoljabbar Irani*; Abdolmajid Hajimoradlo; Naser Agh; Rasul Ghorbani
Volume 5, Issue 3 , March 2017, , Pages 79-106
Abstract
Nitrification rate of biofilters is influenced by ammonia concentration and levels of ammonia vary in response to feeding time. On the other hand, existence and activity of different groups of bacteria can be expected in the biofilters. Hence in this research, nitrification dynamic of biofilters during ...
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Nitrification rate of biofilters is influenced by ammonia concentration and levels of ammonia vary in response to feeding time. On the other hand, existence and activity of different groups of bacteria can be expected in the biofilters. Hence in this research, nitrification dynamic of biofilters during day hours and also rules of different biofilteration process (nitrification, denitrification and anamox) in aerobic biofilters of Common carp recirculating aquaculture system were surveyed. To conduct of this research 12 pilot recirculating aquaculture systems with barley straw, wood chip, sponge and PVC pure pipe based biofilters were designed. After activation of biofilters, nitrification rates measured at day 46 and 61 in 4 hour interval and via sampling of granules from biofilters at day 62, nitrification, denitrification and anamox process were surveyed. Results indicated that nitrification rates were different during day hours, as so peak rates observed in related to feeding time. Nitrification rates in batch culture of granules were greater than maximum rates obtained for biofilters established in recirculating aquaculture systems and these granules showed not only nitrification but also denitrification and relatively anamox activities. In conclude by modifying the management of biobilters all biofilteration process of inorganic nitrogen wastes can be useful.
A. GH. OWNAGH; N. AGH; H. AZIZI; B. H. RAHMAN
Volume 3, Issue 2 , March 2015, , Pages 21-30
Abstract
Use of growth and feeding stimulators have proven to have an important role in the development of aquaculture industry. In this study, we investigated the effect of Lactobacillus plantarum (L. plantarum) and lactoferrin on growth and feeding indices of rainbow trout (Oncorhynchusmykiss). 900 fish (average ...
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Use of growth and feeding stimulators have proven to have an important role in the development of aquaculture industry. In this study, we investigated the effect of Lactobacillus plantarum (L. plantarum) and lactoferrin on growth and feeding indices of rainbow trout (Oncorhynchusmykiss). 900 fish (average weight 20±2 g) were divided into 6 feeding treatments supplemented with different doses of L. plantarum and lactoferrin and were fed for two months. Growth and feeding parameters including wet weight (wet W), standard length (SL), feed conversion ratio (FCR), specific growth rate (SGR) and condition factor (CF) were measured on days 0, 15, 30, 45 and 60 and compared with the control group. The results showed that treatments receiving diets containing L. plantarum 108cfu/kg and treatments that received 200 mg/kg lactoferrin in diet had significantly higher growth compared to the control group (pL. plantarum and lactoferrin did not show any reinforcing effect on feeding and growth parameters. It seems that supplementation of 108cfu of L. plantarum and 200 mg of lactoferrin per kg of diet, alone, is more effective and less expensive way to enhance growth and feeding indices in rainbow trout compared to their combined use.
