Tayebeh Enayat Gholampour, Valiollah Jafari, Mohamad Reza Imanpour, Hamed Kolangi Miandare,
Volume 3, Issue 4 (3-2017)
Abstract
In the research project performed, the effects of different levels of hydro-alcoholic extract Vitex agnus-castus were investigated as nutritional supplement on growth parameters of Danio rerio for 4 months. Since the beginning of the feeding phase up to the age of 4 months (average weight: 2.1±0.1g, length: 5.2±0.3 cm), larvae were fed with expe-rimental diets. Fish treated with diets containing plant extracts had higher growth and survival rate than the control gr-oup (p<0.05). Differences in the level of the extract had no significant effect on the survival rate (p<0.05). The results revealed that the diet containing 15 gr of the extract resulted in the best FCR significantly (p<0.05). By increasing the extract in the diet during the experiment, SGR increased. The highest and the lowest %BWG were observed in treatm-ents T3 and T0 respectively (p<0.05). The highest CF was observed in T3 and the lowest was obtained in T0. All in all, this study proposed that the addition of 15 gr of hydro-alcoholic extract of Vitex agnus-castus in the diet of zebrafish could improve the performance of the growth indices and increase the final biomass. In addition, this extract could be considered as a suitable supplement for Cyprinidae diet.
Mohammadreza Imanpour, Mahrokh Nemati, Hadiseh Afshar, Zahra Roohi,
Volume 5, Issue 1 (6-2018)
Abstract
Feeding frequency and stocking density are important factors affecting growth and maturation of cultured fishes. The aims of this investigation were to determine the effects of stocking density (10, 20, 30 and 40 fish per aquarium) and feeding frequency (2, 3 and 4 times per day) on growth parameters and hematocrit of the Rutilus rutilus caspicus. The experiment was continued for 45 days in two replicates. The results of this study showed that growth parameters, including weigh gain (WG), feed conversion ratio (FCR) and specific growth rate (SGR) were affected significantly by stocking density (P<0.05), but not significantly affected by feeding frequency (P>0.05). The highest WG and SGR were recorded with the lowest stocking density (10 fish / aquarium). The least FCR was obtained in density of 10 fish/aquarium, FCR value was significantly higher with high stocking density (P<0.05). Also, interactions between stocking density and feeding frequency were no significant on growth parameters (P>0.05). Density and feeding frequency hand no significant effect of hematocrit concentration (P>0.05). On the other hand, interactions between stocking density and feeding frequency significantly affected hematocrit levels (P<0.05). The lowest level of hematocrit was observed in density of 10 fish/aquarium at two times / day feeding frequency. The results of this study indicated that density is significantly affected the growth, but increasing of feeding frequency there is not effect on growth in the Rutilus rutilus caspicus.
