1-Department of Fisheries, Faculty of Fisheries and Environment, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran , v.jafari.sh110@gmail.com
2- Department of Fisheries, Faculty of Fisheries and Animal Science, Sari University of Agricultural Sciences and Natural Resources, Sari, Iran |
Introduction: From the point of view of biodiversity and gene pool, sturgeons are actually considered to be one of the few living fossils. Therefore, their importance in this aspect is also significant and vital. Considering the growing trend of human population and the increasing demand for animal protein, especially fish and aquatic animals, increasing production, growth and improving the immune system are important solutions in aquaculture. Therefore, the use of food supplements, such as amino acids and fulvic acid, which, in addition to being desirable in breeding and not posing any risks to the environment and humans, is also important. Therefore, the aim of this study is to use the amino acids arginine and fulvic acid individually and in combination in the diet of Persian sturgeon (Acipenser persicus) juveniles, as one of the most important species of sturgeon in the Caspian Sea, to increase growth and improve the immune system and to affect the expression of growth-related genes (GH and IGF-I).
Material and Methods: For this purpose, 270 Persian sturgeon juveniles with an average weight of about 13.5 grams were released in 27 tanks. Nutritional treatments at the desired levels of the combination of these two based on food (Manaco Company) were added to the fish feed by spraying. And for 8 weeks, they were fed diets containing 0 (control), 1 percent folic acid (treatment 1), 2 percent fulvic acid (treatment 2), 3 percent arginine (treatment 3), 4 percent arginine (treatment 4), 1 percent fulvic acid + 3 percent arginine (treatment 5), 1 percent fulvic acid + 4 percent arginine (treatment 6), 2 percent folic acid + 3 percent arginine (treatment 7) and 2 percent folic acid + 4 percent arginine (treatment 8). erformance evaluation after the end of the project, samples were taken from brain and liver tissue to examine the expression indices of growth-related genes. Tissue samples were extracted in the laboratory using an extraction kit and according to the manufacturer's instructions (Ziistfan Pishro Azma). In addition, all fish in each group were weighed using a digital scale and growth performance indices were calculated.
Results and Diseussion: The results obtained from the evaluation of the growth performance of Persian sturgeon after 8 weeks of feeding with diets containing different levels of folic acid and arginine, and according to the evaluations, the highest final weight (FW), weight gain (WG), and specific growth rate (SGR) were in fish that were fed a diet containing a combination of 2% folic acid and 3% arginine, which was significantly different from the control and other treatments (p<0.05). There was no statistically significant difference in the aforementioned indices between fish fed with different levels of folic acid and arginine (p>0.05), although these groups had significant differences with the control (p<0.05). The lowest feed conversion ratio and the highest value at a significant level were observed in treatment 7 and the control group, respectively (p<0.05). Also, the expression level of IGF gene in fish fed with diets containing a combination of different levels of folic acid and arginine did not show a significant difference (p>0.05). However, the highest expression level was observed in the treatment of 1% folic acid and 4% arginine (treatment 7). There was no statistically significant difference between the different levels of folic acid and the control (p>0.05). The results obtained are from the expression of the GH gene. According to the results, the highest expression level of this gene was in treatment 7 (2% folic acid + 3% arginine), which had a significant difference with the other treatments (p<0.05). The lowest expression level of this gene was in the 4% arginine treatment, which was not significantly different from the control and 1% folic acid (p>0.05).
Conclusion: The present study clearly showed that the use of folic acid and arginine in the diet of Persian sturgeon juveniles had a significant effect on growth performance. And the highest final weight, weight gain and specific growth rate were in fish that had 2% folic acid and 3% arginine in their diet. In addition, the use of these compounds in the diet also significantly reduced the feed conversion ratio compared to the control group. The results of this study showed that the use of a combination of folic acid and arginine caused significant changes in the expression levels of GH and IGF genes in Persian sturgeon, which was significantly different from the control group. The results showed that the highest growth performance and the lowest feed conversion ratio were significantly different from the control group in treatment 7 (2% folic acid + 3% arginine). The highest expression levels of GH and IGF genes were also in treatment 7. Therefore, it can be concluded that the use of folic acid and arginine in the diet of Persian sturgeon can have a positive effect on the growth of this species |
