Abstract
This study was conducted to investigate the effects of different levels of Bentomax Plus supplementation on the growth performance, feeding utilization, and body biochemical composition of common carp (Cyprinus carpio) for 64 days. The 450 fish with an initial average weight of 5.25 ± 0.60 g were stocked in the six treatments. The experimental treatments included treatment 1 (control, without adding supplements) and five experimental treatments with diets containing 1, 3, 5, 7, and 9 g/kg of diet. At the end of the experimental period, a significant difference was observed in the weight gain, body length increase, and specific growth rate between the experimental treatments. Treatment 1 showed the lowest amount. Although, there was not a significant difference between treatments 3 and 6 in the specific growth rate. No significant difference was observed in survival and condition factors between the treatments. Nevertheless, the feed conversion ratio and survival were found to be negatively correlated using the correlation coefficient test. The control treatment had the highest feed conversion ratio measurements, and treatment 6 had the lowest. In the economic conversion ratio, the highest rate was recorded in treatment 1 and the lowest rate in treatment 6. A comparison of changes in weight gain and economic conversion ratio showed a reverse trend between these two indicators. Compared to the control treatment, supplements-containing treatments had higher protein contents; the highest protein contents were found in treatments 3 and 4, while the lowest protein contents were found in treatments 1 and 2. Treatments 4 and 1 had the highest and lowest lipid contents, respectively. Between experimental treatments, there was not a significant difference in the ash or moisture contents. The findings of the current study demonstrated that common carp's growth performance, feeding efficiency, and body biochemical compositions are all improved by using Bentomax Plus as a dietary supplement. Therefore, based on the overall results of this study, it is recommended that common carp supplement their diet with at least 3 to 9 g/kg of Bentomax Plus.
Introduction
Bentomax Plus is a commercial supplement that consists of several substances including beta-glucanase enzyme, yeast cell wall, lactobacillus bacteria, aluminum silicates (montmorillonite), and organic acids (lactic acid). This supplement has gained attention due to the presence of substances like organic acids, minerals, and beta-glucanase enzymes, and their potential impact on growth and nutrition variables. The Bentomax Plus is now available in the market. However, there is no scientific report available yet on the performance and effects of different levels of this supplement on growth indicators, feeding, and biochemical compositions of any aquatic species. Considering the composition of this supplement, the importance of common carp as a cultured species, and the previous studies in this regard, this research aims to investigate the effects of different levels of Bentomax Plus supplement on the growth, feeding, economic indicators, and the biochemical body composition of common carp (C. carpio).
Materials and methods
Six experimental treatments were designed in three replications. Therefore, treatment 1 has no supplement (control treatment), treatment 2 includes 1 g/kg supplement in the diet, treatment 3 includes 3 g/kg supplement in the diet, treatment 4 includes 5 g/kg supplement in the diet, and treatment 5 includes 7 g/kg supplement in the diet. kg of supplement in diet and treatment 6, including 9 g/kg of supplement in diet, were considered. Bentomax Plus was obtained from Chitica (Iran). 450 common carp with an average initial weight of 5.25 ± 0.60 g were prepared for a study at Khorramshahr University of Marine Sciences and Technologies. They were transferred to a wet laboratory and adapted to the conditions there for 7 days. During this period, they were fed a basic commercial diet (control treatment) three times a day until they were full. After the adaptation period, the fish were divided into tanks with a density of 25 fish per 300-litre polyethylene tank and cultured for 64 days. The experimental fish were weighed and measured at the beginning and end of the experiment period.
Results
At the end of the experimental period, a significant difference was observed in the weight gain, body length increase, and specific growth rate between the experimental treatments. Treatment 1 showed the lowest amount. Although there was not a significant difference between treatments 3 and 6 in the specific growth rate. No significant difference was observed in survival and condition factors between the treatments. Nevertheless, the feed conversion ratio and survival were found to be negatively correlated using the correlation coefficient test. The control treatment had the highest feed conversion ratio measurements, and treatment 6 had the lowest. In the economic conversion ratio, the highest rate was recorded in treatment 1 and the lowest rate in treatment 6. A comparison of changes in weight gain and economic conversion ratio showed a reverse trend between these two indicators. Compared to the control treatment, supplements-containing treatments had higher protein contents; the highest protein contents were found in treatments 3 and 4, while the lowest protein contents were found in treatments 1 and 2. Treatments 4 and 1 had the highest and lowest lipid contents, respectively. Between experimental treatments, there was not a significant difference in the ash or moisture contents.
Discussion
Based on the findings of this research study, it was observed that adding Bentomax Plus supplement to the diet of carp during a 64-day culturing period had a positive effect on growth, feeding, economics, and biochemical composition. Among all the treatments, Treatment 6 (9 g/kg) yielded the best growth in terms of body length and SGR, along with the highest protein content and lowest FCR and ECR. These results indicate that Bentomax Plus can be a beneficial supplement for the diet of common carp, improving growth indicators and body biochemical compositions. The study suggests that adding at least 3 to 9 g/kg of Bentomax Plus supplement to the diet of common carp (Cyprinus carpio) can be beneficial.