Omidvar Farhadian, Seyed Mojtaba Fallahi, Nasrollah Mahboobi Soofiani,
Volume 1, Issue 1 (3-2013)
Abstract
In order to determine effects of chicken and cattle manures in culture of Chlorococcum, an experiment was designed in six treatments including; 0.1, 0.4, 0.8 g/l of chicken manure and 0.1, 0.4, 0.8 g/l of cattle manure as completely randomize design with three replicates for 28 days. Results showed that the mean maximum density (87.1 × 105 cell/ml), specific growth rate (0.054 day-1), algal dry biomass (0.644 g/l), and chlorophyll a (9.42 mg/l) were obtained with 0.8 mg/l chicken manure. In order to compare performance of these manures with other culture media, second experiment with five treatments including; BBM (control) (Bold’s Basal Medium), BBM + soil extract, 0.8 g/l chicken manure, 0.8 g/l cattle manure and mixture of all treatment (BBM, BBM + soil extract, chicken manure and cattle manure) was designed as completely randomize design with three replicates for 15 days. Comparative results showed that BBM + soil extract had highest algal density (11.6 x 106 cells/ml), highest algal dry biomass (0.81 mg/ml), maximum SGR (0.13 /day), highest chlorophyll a (10.15 mg/l) and minimum doubling time (4.97 days). In conclusion, performance of BBM + soil extract was better in terms of biomass and growth parameters of Chlorococcum.
Elham Dehghan, Abdolsamad Keramat, Hossein Oraji, Khosro Jani Khalili,
Volume 4, Issue 1 (6-2015)
Abstract
The present study was to evaluate the impact of feeding level and fish size on the growth factors,carcass composition and digestibility of rainbow trout. Six experimental treatments were assigned by the use of three feeding levels (maintenance, medium and satiation levels) and two fish sizes (43.02 ± 2.93 and 231.32± 6.74g) according to a 3×2 factorial design. There were three replicates for each treatment and the experiment lasted for 59 days. The results showed that there is a significant interaction effect between fish size and feeding level for body weight gain, final body weight and specific growth (p<0.05). Body composition (dry matter, energy, moisture, fat and protein) was affected by feeding level and size of the fish (p<0.05). However, the interaction effect between fish size and feeding level for body composition was not significant (p>0.05).The digestibility measurements showed that fish size and feeding level changed significantly digestibility of protein, lipid, energy and dry matter in rainbow trout (p<0.05). Maximum growth at satiation feeding level can reduce feed conversion ratio and increase waste production at both fish sizes.
